Towards routine, reusable space launch.

[Robert Clark]

Several companies are proposing satellite megaconstellations that would
require hundreds to thousands of communications satellites. This may finally
provide the impetus to produce reusable launchers.

Proponents of reusable launchers such as SpaceX have argued by producing
them the costs of launch will be reduced which will drive an increase in the
market that will pay for their development. However, the OldSpace companies
have maintained the market for launch is not enough to justify the expense
of developing reusable launchers. But without reusability the price for
launch is too high to generate a large market. So we have a "chicken or the
egg" type problem.

But the hundreds to perhaps thousands of launches required for the new
megaconstellations may finally provide the necessary market. The NewSpace
companies SpaceX and Blue Origin are already committed to reusability. But
in a surprise the OldSpace company Arianespace while previously discounting
the viability of reusable launchers has announced they will transition to
reusable launchers also, citing the impending market provided by the
megaconstellation satellites.

Here's a discussion of a fast route to reusable launchers for ArianeSpace
that could lead to a manned launcher as well:

A half-size Ariane for manned spaceflight.
https://exoscientist.blogspot.com/2014/11/a-half-size-ariane-for-manned.html

Bob Clark

------------------------------------------------------------------
Single-stage-to-orbit was already shown possible 50 years ago
with the Titan II first stage.
In fact, contrary to popular belief SSTO's are actually easy.
Just use the most efficient engines and stages at the same time,
and the result will automatically be SSTO.
Blog: Http://Exoscientist.blogspot.com
------------------------------------------------------------------

[Robert Clark]

=========================================================
"Robert Clark" wrote in message news:pfc49a$gv2$***@dont-email.me...

Here's a discussion of a fast route to reusable launchers for ArianeSpace
that could lead to a manned launcher as well:

A half-size Ariane for manned spaceflight.
https://exoscientist.blogspot.com/2014/11/a-half-size-ariane-for-manned.html

===========================================================

Sorry, that link should have been:

Half-size Ariane core stage for a reusable launcher.
http://exoscientist.blogspot.com/2018/06/half-size-ariane-core-stage-for.html

Bob Clark


------------------------------------------------------------------
Single-stage-to-orbit was already shown possible 50 years ago
with the Titan II first stage.
In fact, contrary to popular belief SSTO's are actually easy.
Just use the most efficient engines and stages at the same time,
and the result will automatically be SSTO.
Blog: Http://Exoscientist.blogspot.com
------------------------------------------------------------------

[Fred J. McCall]

Post by Robert Clark
Several companies are proposing satellite megaconstellations that would
require hundreds to thousands of communications satellites. This may finally
provide the impetus to produce reusable launchers.
Proponents of reusable launchers such as SpaceX have argued by producing
them the costs of launch will be reduced which will drive an increase in the
market that will pay for their development. However, the OldSpace companies
have maintained the market for launch is not enough to justify the expense
of developing reusable launchers. But without reusability the price for
launch is too high to generate a large market. So we have a "chicken or the
egg" type problem.

A big driver is that the cost of launching tends to drive the cost of
what you launch. If you're going to have to spend $200 million to get
your payload on station, you're going to spend a lot of money making
your payload large, reliable, and capable so that you're not wasting
that money. That drives the cost of your payload up.

Cut the cost of launching to 30% of that and suddenly launching
cheaper and less capable payloads becomes practical. The problem is
that nobody really knows what the elasticity of demand is for
launches.

[Doc O'Leary]

For your reference, records indicate that

Post by Robert Clark
Several companies are proposing satellite megaconstellations that would
require hundreds to thousands of communications satellites. This may finally
provide the impetus to produce reusable launchers.

What are the actual numbers when it comes to savings from a reusable
rocket? It’d also be interesting to know how new technologies might
impact the economics of launching items into space (including just making
disposable launch vehicles much cheaper). Once you start to contemplate
the need for multiple daily launches, even recovering boosters to reuse
them seems like a slow and labor-intensive process. On the path to a
space elevator, it seems like there should be many more ways to reach
escape velocity that do a better job than what Musk is doing today.

[Sergio]

Post by Doc O'Leary
On the path to a
space elevator, it seems like there should be many more ways to reach
escape velocity that do a better job than what Musk is doing today.

space elevator - ever do any calculations on that ? like lift power
required, mechanical loads, electrical losses, how to aim, ....

It is simply a mechanical constraint on launching a rocket, like the
rail gun, seems like a nice idea until you try to build one. (navy has
discontinued rail gun)

[Fred J. McCall]

Post by Doc O'Leary
For your reference, records indicate that

Post by Robert Clark
Several companies are proposing satellite megaconstellations that would
require hundreds to thousands of communications satellites. This may finally
provide the impetus to produce reusable launchers.

What are the actual numbers when it comes to savings from a reusable
rocket?

That depends on a lot of things.

Post by Doc O'Leary
It’d also be interesting to know how new technologies might
impact the economics of launching items into space (including just making
disposable launch vehicles much cheaper).

Real reuse will always be cheaper. If you can make disposable launch
vehicles much cheaper, the same technologies allow making reusable
launch vehicles much cheaper.

Post by Doc O'Leary
Once you start to contemplate
the need for multiple daily launches, even recovering boosters to reuse
them seems like a slow and labor-intensive process.

But orders of magnitude faster than throwing them away and building a
new one.

Post by Doc O'Leary
On the path to a
space elevator, it seems like there should be many more ways to reach
escape velocity that do a better job than what Musk is doing today.

You've discovered a good supply of unobtainium, have you? Otherwise,
rockets are your man for getting stuff to orbit for the foreseeable
future.

[Doc O'Leary]

For your reference, records indicate that

Post by Fred J. McCall

Post by Doc O'Leary
What are the actual numbers when it comes to savings from a reusable
rocket?

That depends on a lot of things.

Well, sure, but it always helps to have some data to work with before
beginning an optimization process. Best/worst cases or averages or
whatever. What the savings is related to the total cost of the launch
is going to be guiding factor on how much effort it makes sense to
expend to re-use different parts of the system.

Post by Fred J. McCall

Post by Doc O'Leary
It’d also be interesting to know how new technologies might
impact the economics of launching items into space (including just making
disposable launch vehicles much cheaper).

Real reuse will always be cheaper. If you can make disposable launch
vehicles much cheaper, the same technologies allow making reusable
launch vehicles much cheaper.

That is non-obvious. Ideally, I would think a “zero waste” system
would be cheapest; every kg of mass that gets sent up either stays up
(doing something useful) or was the fuel. All this booster landing
(and subsequent refurbishing for relaunch) we’re seeing, while cool,
is definitely *not* the most efficient use of resources.

Post by Fred J. McCall

Post by Doc O'Leary
Once you start to contemplate
the need for multiple daily launches, even recovering boosters to reuse
them seems like a slow and labor-intensive process.

But orders of magnitude faster than throwing them away and building a
new one.

But that’s still assuming old technologies rather than new ones. You
don’t “throw away” a space elevator. Nor a mag-lev cannon. I’m not
sure how viable a high-altitude balloon launch would be, but it may
also be cheaper than traditional first-stage rockets.

Post by Fred J. McCall

Post by Doc O'Leary
On the path to a
space elevator, it seems like there should be many more ways to reach
escape velocity that do a better job than what Musk is doing today.

You've discovered a good supply of unobtainium, have you? Otherwise,
rockets are your man for getting stuff to orbit for the foreseeable
future.

It’s always a good idea to noodle around with other technologies, no
matter how impossible they appear to be today. Because, yes, rockets
are the way to get to orbit, but I’m most interested in the
*unforeseeable* future that has humans on other planets around other
stars. Just being satisfied with rockets is not going to make that
happen.

[Jeff Findley]

In article <pfh27b$ghr$***@dont-email.me>, droleary@
2017usenet1.subsume.com says...

Post by Doc O'Leary
For your reference, records indicate that

Post by Fred J. McCall

Post by Doc O'Leary
What are the actual numbers when it comes to savings from a reusable
rocket?

That depends on a lot of things.

Well, sure, but it always helps to have some data to work with before
beginning an optimization process. Best/worst cases or averages or
whatever. What the savings is related to the total cost of the launch
is going to be guiding factor on how much effort it makes sense to
expend to re-use different parts of the system.

Post by Fred J. McCall

Post by Doc O'Leary
It?d also be interesting to know how new technologies might
impact the economics of launching items into space (including just making
disposable launch vehicles much cheaper).

Real reuse will always be cheaper. If you can make disposable launch
vehicles much cheaper, the same technologies allow making reusable
launch vehicles much cheaper.

That is non-obvious. Ideally, I would think a ?zero waste? system
would be cheapest; every kg of mass that gets sent up either stays up
(doing something useful) or was the fuel. All this booster landing
(and subsequent refurbishing for relaunch) we?re seeing, while cool,
is definitely *not* the most efficient use of resources.

Falcon 9 is the "first generation" reuse for SpaceX. For "zero waste",
you'll have to wait for their "second generation" which will be BFR/BFS.

Post by Doc O'Leary

Post by Fred J. McCall

Post by Doc O'Leary
Once you start to contemplate
the need for multiple daily launches, even recovering boosters to reuse
them seems like a slow and labor-intensive process.

But orders of magnitude faster than throwing them away and building a
new one.

But that?s still assuming old technologies rather than new ones. You
don?t ?throw away? a space elevator. Nor a mag-lev cannon. I?m not
sure how viable a high-altitude balloon launch would be, but it may
also be cheaper than traditional first-stage rockets.

High altitude balloon launch is a tad risky and only gains you a bit of
altitude and zero velocity. Not worth the complexity and cost, IMHO.

Post by Doc O'Leary

Post by Fred J. McCall

Post by Doc O'Leary
On the path to a
space elevator, it seems like there should be many more ways to reach
escape velocity that do a better job than what Musk is doing today.

You've discovered a good supply of unobtainium, have you? Otherwise,
rockets are your man for getting stuff to orbit for the foreseeable
future.

It?s always a good idea to noodle around with other technologies, no
matter how impossible they appear to be today. Because, yes, rockets
are the way to get to orbit, but I?m most interested in the
*unforeseeable* future that has humans on other planets around other
stars. Just being satisfied with rockets is not going to make that
happen.

Sure, but SpaceX has proven that you can reduce costs dramatically by
using existing technology and introducing reuse of as many components as
possible. They're getting close to catching fairings and they have some
ideas for second stage reuse too. That would be very close to "zero
waste" with Falcon, if they can get to that point.

BFR/BFS is planned to be "zero waste" from the very beginning. Fully
reusable TSTO with "gas and go" like operations.

Also don't count out Blue Origin. They're off to a slow start, but have
a very reliable funding source in Jeff Bezos ($1 billion a year).

Besides, how you going to get those space elevator bits into orbit?
That's right, conventional (hopefully reusable) launch vehicles.

Jeff

[Doc O'Leary]

For your reference, records indicate that

Post by Jeff Findley
High altitude balloon launch is a tad risky and only gains you a bit of
altitude and zero velocity. Not worth the complexity and cost, IMHO.

Like I said, it might not *currently* be viable, but as an alternative
technology it brings new sets of trade-offs to the table such that a few
tweaks here and there might make it viable for certain kinds of launches
(e.g., “bulky” items that are hard to make aerodynamically efficient
benefit from starting at the highest possible altitude).

Post by Jeff Findley
BFR/BFS is planned to be "zero waste" from the very beginning. Fully
reusable TSTO with "gas and go" like operations.

But that’s not the true “zero waste” I was talking about. Any resources
that you’re sending up *and* down, along with any fuels you burn to do it
safely, is a waste. It may be a necessary waste for the current launch
technologies, so it’s good to minimize it, but I still say it’s a good
idea to think about ways to shoot stuff into space that doesn’t involve a
lot of heavy stuff coming back to Earth.

Post by Jeff Findley
Also don't count out Blue Origin. They're off to a slow start, but have
a very reliable funding source in Jeff Bezos ($1 billion a year).

I’m not counting them out, but when the topic is cost/efficiency, the
basic question is still how much energy is being expended to get each
kg into orbit. So long as the idea is still to send a lot of
supporting (non-fuel) heavy stuff up only to have most of it come back
down, there are wastes that a new technology can come in and improve
upon.

Post by Jeff Findley
Besides, how you going to get those space elevator bits into orbit?
That's right, conventional (hopefully reusable) launch vehicles.

Hope for bigger things. I fully believe that, for a society to be
advanced enough to make a space elevator project realistic, it’s value
would be more incremental than revolutionary. Rockets are the best we
have right now, but we’re stuffed if that’s the best we can do.

[Sergio]

Post by Doc O'Leary
For your reference, records indicate that
Hope for bigger things. I fully believe that, for a society to be
advanced enough to make a space elevator project realistic, it’s value
would be more incremental than revolutionary.

A space elevator is not possible in reality. It is a running joke in
engineering land.

calculate the mechanical loads.

calculate the weight of copper cables, and the mechanical cables

calculate the weight of the tower, and estimate the sizes of tower
sections to support the weight at different levels

estimate the weight of the electric motor 150 HP

going to use a counterweight ?


just ballpark it, assume 0.1 m/sec and 2000 # weight of cargo, and
100,000 foot high.

[Thomas Koenig]

Post by Doc O'Leary
I’m not counting them out, but when the topic is cost/efficiency, the
basic question is still how much energy is being expended to get each
kg into orbit.

At the moment, not at all. Ballpark calculation:

An older version of a Falcon 9 reportedly had 488 tons of total
fuel, 147 of it RP-1 (a modified kerosene). Liquid oxygen is
quite cheap, and if we give RP-1 a cost of 1 dollar per kg,
we probably are in the right ballpark. So, around 150 000 Dollar
per launch.

This is _very_ low compared to all the other costs. A launch
cost around 50 to 60 million dollars now, if I remember the
figures right.

[Doc O'Leary]

For your reference, records indicate that

Post by Thomas Koenig
An older version of a Falcon 9 reportedly had 488 tons of total
fuel, 147 of it RP-1 (a modified kerosene). Liquid oxygen is
quite cheap, and if we give RP-1 a cost of 1 dollar per kg,
we probably are in the right ballpark. So, around 150 000 Dollar
per launch.
This is _very_ low compared to all the other costs. A launch
cost around 50 to 60 million dollars now, if I remember the
figures right.

That’s just the problem: you’re only accounting for the cost of the fuel, whereas I would consider large parts of “all the other costs” as inherently part of the efficiency equation. After all, if we found a way to eliminate the boosters entirely, the savings is obviously not just from the decrease in fuel.

[Fred J. McCall]

Post by Doc O'Leary
For your reference, records indicate that

Post by Thomas Koenig
An older version of a Falcon 9 reportedly had 488 tons of total
fuel, 147 of it RP-1 (a modified kerosene). Liquid oxygen is
quite cheap, and if we give RP-1 a cost of 1 dollar per kg,
we probably are in the right ballpark. So, around 150 000 Dollar
per launch.
This is _very_ low compared to all the other costs. A launch
cost around 50 to 60 million dollars now, if I remember the
figures right.

That’s just the problem: you’re only accounting for the cost of the fuel, whereas I would consider large parts of “all the other costs” as inherently part of the efficiency equation. After all, if we found a way to eliminate the boosters entirely, the savings is obviously not just from the decrease in fuel.

Yes, if you postulate the existence of magic everything gets much
easier.

[Jeff Findley]

In article <pfmsfl$mab$***@dont-email.me>, droleary@
2017usenet1.subsume.com says...

Post by Doc O'Leary
For your reference, records indicate that

Post by Thomas Koenig
An older version of a Falcon 9 reportedly had 488 tons of total
fuel, 147 of it RP-1 (a modified kerosene). Liquid oxygen is
quite cheap, and if we give RP-1 a cost of 1 dollar per kg,
we probably are in the right ballpark. So, around 150 000 Dollar
per launch.
This is _very_ low compared to all the other costs. A launch
cost around 50 to 60 million dollars now, if I remember the
figures right.

That?s just the problem: you?re only accounting for the cost of
the fuel, whereas I would consider large parts of ?all the other
costs? as inherently part of the efficiency equation. After all,
if we found a way to eliminate the boosters entirely, the savings
is obviously not just from the decrease in fuel.

Sure, sure, Star Trek style transporters with infinite range. I'll get
right on that.

Meanwhile, in the real world, that's not how to optimize the cost of a
transportation system in order to minimize the $ per kg to orbit.

Jeff

[Doc O'Leary]

For your reference, records indicate that

Post by Jeff Findley
Sure, sure, Star Trek style transporters with infinite range. I'll get
right on that.

No, you won’t. But you apparently *will* use it as a straw man to avoid
actually addressing the likelihood that new technologies developed in
the future will change the economies of space launches. Hell, that’s
essentially what SpaceX is demonstrating today.

[Fred J. McCall]

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
Sure, sure, Star Trek style transporters with infinite range. I'll get
right on that.

No, you won’t. But you apparently *will* use it as a straw man to avoid
actually addressing the likelihood that new technologies developed in
the future will change the economies of space launches. Hell, that’s
essentially what SpaceX is demonstrating today.

Nope. SpaceX is using OLD technologies in slightly new ways. That's
what engineers do. What you're talking about is, well, what loons do.

[Jeff Findley]

In article <pfolpv$t6n$***@dont-email.me>, droleary@
2017usenet1.subsume.com says...

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
Sure, sure, Star Trek style transporters with infinite range. I'll get
right on that.

No, you won?t. But you apparently *will* use it as a straw man to avoid
actually addressing the likelihood that new technologies developed in
the future will change the economies of space launches. Hell, that?s
essentially what SpaceX is demonstrating today.

Bullshit. SpaceX is not demonstrating any new technologies. They've
combined existing technologies in novel ways to solve the problems
involved in building Merlin engines and Falcon launch vehicles. There
is zero new tech in them. If you believe differently, name a new
technology they're using in their engines, launch vehicles, Dragon, and
etc.

The fact is that any other engine manufacturer, launch vehicle provider,
and spacecraft manufacturer could have done the same things. In fact,
Blue Origin *is* doing much the same with New Glenn.

Jeff

[JF Mezei]

Post by Jeff Findley
Bullshit. SpaceX is not demonstrating any new technologies.

Is friction fit welding for the tanks a first for rockets?

I know it isn't "new" since it was used by Airbus and others, but
wondering if it was first use in rockets/tanks.


Since SpaceX is developping composite tanks for BFR, was there any
though of puttting composite tanks for Block 5 Falcon 9? Just
wondering if there would be a big payback in weight or if the difference
not worth the trouble of developping/testing/certifying such a tank.

[Fred J. McCall]

Post by JF Mezei

Post by Jeff Findley
Bullshit. SpaceX is not demonstrating any new technologies.

Is friction fit welding for the tanks a first for rockets?
I know it isn't "new" since it was used by Airbus and others, but
wondering if it was first use in rockets/tanks.

I suspect it was used for wheels on rail cars and other similar things
long before it was used on aircraft (and frankly it seems a poor fit
for aircraft use).

Post by JF Mezei
Since SpaceX is developping composite tanks for BFR, was there any
though of puttting composite tanks for Block 5 Falcon 9? Just
wondering if there would be a big payback in weight or if the difference
not worth the trouble of developping/testing/certifying such a tank.

I doubt it. They were more interested in fixing the existing COPV
design than grounding waiting for a whole new technology.

[Jeff Findley]

Post by JF Mezei

Post by Jeff Findley
Bullshit. SpaceX is not demonstrating any new technologies.

Is friction fit welding for the tanks a first for rockets?
I know it isn't "new" since it was used by Airbus and others, but
wondering if it was first use in rockets/tanks.

Doesn't matter if it's a "first for rockets", it's been done before in
other industries (aerospace at that). So, it's absolutely existing
tech. Again, SpaceX hasn't invented any new technologies here.

Post by JF Mezei
Since SpaceX is developping composite tanks for BFR, was there any
though of puttting composite tanks for Block 5 Falcon 9? Just
wondering if there would be a big payback in weight or if the difference
not worth the trouble of developping/testing/certifying such a tank.

Composite structures/tanks are also not new. Composites are heavily
used in aerospace. For space specifically, the X-33 program designed
and built cryogenic composite tanks. They failed during testing more
due to their complex geometry than anything else. So no new tech there.

BFR/BFS avoids the complex geometry problem and goes back to a more
"delta clipper" sort of design. Also not new, at least in concept.

Jeff

[JF Mezei]

Post by Jeff Findley
Composite structures/tanks are also not new. Composites are heavily
used in aerospace. For space specifically, the X-33 program designed
and built cryogenic composite tanks. They failed during testing...

Have cryogenic fuel/O2 tanks made solely of composites ever been
sucesfully used in production rockets?

If BFR manages to have all composite tanks that work, doesn't that
constitute innovation?

Composites were not new to airplanes. But Boeing (with NASA funding)
developped the tech and knowledge of how to produce single piece
sections of fuselages, complete with the stringers (787 programme).
While the material was not new, its application was.

[Fred J. McCall]

Post by JF Mezei

Post by Jeff Findley
Composite structures/tanks are also not new. Composites are heavily
used in aerospace. For space specifically, the X-33 program designed
and built cryogenic composite tanks. They failed during testing...

Have cryogenic fuel/O2 tanks made solely of composites ever been
sucesfully used in production rockets?
If BFR manages to have all composite tanks that work, doesn't that
constitute innovation?

'Innovation' using an existing technology.

Post by JF Mezei
Composites were not new to airplanes. But Boeing (with NASA funding)
developped the tech and knowledge of how to produce single piece
sections of fuselages, complete with the stringers (787 programme).
While the material was not new, its application was.

So it was existing technology.

[Jeff Findley]

Post by JF Mezei

Post by Jeff Findley
Composite structures/tanks are also not new. Composites are heavily
used in aerospace. For space specifically, the X-33 program designed
and built cryogenic composite tanks. They failed during testing...

Have cryogenic fuel/O2 tanks made solely of composites ever been
sucesfully used in production rockets?

No, but it was a clearly existing technology applied in a new way, so
it's not a new technology. Just because I fly something into space for
the first time doesn't mean it's new technology.

When the two Raspberry Pi single board computers flew to ISS for the
first time, they weren't new technology. The only thing different
between them and the ones in my own house were the fancy milled aluminum
cases/heatsinks and the "sense HAT" add-on board that you can buy off
the shelf. No new tech there.

https://www.raspberrypi.org/education/programmes/astro-pi/

https://makezine.com/2015/12/01/raspberry-pi-iss/

Post by JF Mezei
If BFR manages to have all composite tanks that work, doesn't that
constitute innovation?

Innovation in terms of engineering, but not new technology.

Post by JF Mezei
Composites were not new to airplanes. But Boeing (with NASA funding)
developped the tech and knowledge of how to produce single piece
sections of fuselages, complete with the stringers (787 programme).
While the material was not new, its application was.

NASA and Boeing weren't the first to put composites into aircraft. As
you say, they were working on larger single piece composites. It was
important R&D work to expand the use of composites, but they didn't
invent carbon fiber composites and they weren't the first to try to use
them to build complete fuselages (Scaled Composites certainly did this
earlier than Boeing).

the rise of carbon fiber reinforced plastics
http://www.craftechind.com/the-rise-of-carbon-fiber-reinforced-plastics/

From above:

In the 1960?s, Dr. Akio Shindo at the Agency of Industrial Science
and Technology in Japan developed a carbon fiber based on
polyacrylonitrile (PAN). The resulting fiber contained 55% carbon.

The PAN-based conversion process quickly became the primary method
for producing carbon fiber. Ninety percent of carbon fibers today
are made from polyacrylonitrile (C3H3N)n or PAN a synthetic,
semi-crystalline organic polymer resin.

So, those Boeing fueslages, and the upcoming tanks/structure of BFR/BFS,
are both based on carbon fiber composite technologies that are well over
half a century old.

3D printing is a newer technology now being applied to aircraft engines
and liquid fueled rocket engines. It appeared in the late 20th century.
Specifically selective laser sintering (SLS) was "developed and
patented" in the mid 1980s. The original patents have since expired, so
the technology is now seeing quite wide spread use.

https://en.wikipedia.org/wiki/Selective_laser_sintering

Yes, rocket engines with 3D printed parts are relatively new, but
they're built using SLS technology which was developed in the 1980s,
over 30 years ago.

Jeff

[JF Mezei]

Post by Jeff Findley
Innovation in terms of engineering, but not new technology.

OK, I understand your argument.

But just because carbon fibre has existed for some time does not
automatically "void" the "new technology" when it is used in new
applications such as cryo tanks or aircraft fuselage.


Carbon/fibreglass were originally just "fabric" that was cut to right
shape, layed up and resin applied to it and let it cure.

Wouldn't you agree that it is new technology to take the raw strands in
a large spool, and lay individual strands in a computer optimized
position/direction just after the strand has been impregentated with resin?

This new tech allows totally new applications that were not possible
before with that same material.

Airbus for instance developped new tech to combine 2 existing materials:
glass fibre and aluminium (Glare which has layers of aluminium, layes of
glass fibtre composited together). You can view this as either a new
material, or just "engineering" of 2 existing materials.


Coming back to SpaceX, I am not sure if their building an all composite
cryo tank for BFR represents new tech or not. If they are using the same
techniques/equipment as Boeing uses for the 787 for instance, it woudn't
be "new technology". But it is also possible that they develop new way
to lay the fibre to make the tank. There is also the issue of the resin
and how it is cured which could potentially represent new tech
(especially if they do away with an autoclave or curing oven).

[Jeff Findley]

Post by JF Mezei

Post by Jeff Findley
Innovation in terms of engineering, but not new technology.

OK, I understand your argument.
But just because carbon fibre has existed for some time does not
automatically "void" the "new technology" when it is used in new
applications such as cryo tanks or aircraft fuselage.
Carbon/fibreglass were originally just "fabric" that was cut to right
shape, layed up and resin applied to it and let it cure.

True, but that's essentially still the state of the art today.
Composite layup machines have been around for decades. A guy I used to
work with wrote the layup software for the Cincinnati Milacron machines
back in the 1980s. What they sell today evolved from those machines:

https://metal-cutting-
composites.fivesgroup.com/products/composites/fiber-placement-
systems/cincinnati-viper-fps.html

Post by JF Mezei
Wouldn't you agree that it is new technology to take the raw strands in
a large spool, and lay individual strands in a computer optimized
position/direction just after the strand has been impregentated with resin?

Nope, as I said, been done at least since the 1980s in an automated
fashion. Sure the tech keeps getting better allowing for bigger
structures, but it's an evolution of tech that's decades old.

Post by JF Mezei
This new tech allows totally new applications that were not possible
before with that same material.
glass fibre and aluminium (Glare which has layers of aluminium, layes of
glass fibtre composited together). You can view this as either a new
material, or just "engineering" of 2 existing materials.

Materials tech is always evolving. This is a tad different than carbon
fiber layup, so I'd count that as new, whenever it was first done. I'm
not a materials engineer, so I don't know when that would be for glass
fiber and aluminum.

Post by JF Mezei
Coming back to SpaceX, I am not sure if their building an all composite
cryo tank for BFR represents new tech or not. If they are using the same
techniques/equipment as Boeing uses for the 787 for instance, it woudn't
be "new technology". But it is also possible that they develop new way
to lay the fibre to make the tank. There is also the issue of the resin
and how it is cured which could potentially represent new tech
(especially if they do away with an autoclave or curing oven).

X-33 attempted to do just that. It failed due to the complex geometry.
BFR/BFS is sticking with traditional cylindrical tanks, which is a
proven geometry for carbon fiber composites. They're being pretty
conservative as far as their use of carbon fiber goes, IMHO.

From what I've read, they'll be sticking with traditional techniques to
minimize development risks. I fully expect them to cure it in an
autoclave.

Orbital ATK, or whatever it's called now, is doing much the same with
their OmegA SRB segments. Again, this is a proven technology used by
Orbital ATK for many programs. NASA had a composite wound SRB program
many decades ago. It was canceled due to cost overruns, but that
technology is in use today and proposed for SRB upgrades for SLS, but
that wouldn't fly for maybe 10+ years given the pace of SLS Block 1
development.

http://www.spaceflightinsider.com/organizations/nasa/one-on-one-with-
atks-charlie-precourt-about-composite-materials-and-nasas-space-launch-
system/

Jeff

[JF Mezei]

Post by Jeff Findley
True, but that's essentially still the state of the art today.
Composite layup machines have been around for decades.

Wasn't aware of that. If that is the case, then you are correct.

Post by Jeff Findley
fiber layup, so I'd count that as new, whenever it was first done. I'm
not a materials engineer, so I don't know when that would be for glass
fiber and aluminum.

Developped by/for Airbus as part of many years og R&D un mid/late 1990s
when Airbus wanted to make the A380 but knew it woudln't be economical
(too heavy) with current tech. It wasn't till they solved a number of
weight and landing gear problems that they could launch the project
formally.

BFR/BFS may have similar scalability problems since weight is also a big
issue. But they won't have to worry about landing pad being strong
enough for it since they can build their own.

Post by Jeff Findley
X-33 attempted to do just that. It failed due to the complex geometry.
BFR/BFS is sticking with traditional cylindrical tanks, which is a
proven geometry for carbon fiber composites. They're being pretty
conservative as far as their use of carbon fiber goes, IMHO.

Had forgotten about the odd shape for X33 tanks being reason for failure.

Post by Jeff Findley
From what I've read, they'll be sticking with traditional techniques to
minimize development risks. I fully expect them to cure it in an
autoclave.

Yet, that BFR all composite tank is at a scale nobody has productized
before. Just because they seem to have been able to build/test it
doesn't mean that it is "conventional" in design or using off-the-shelf
resin.

[Jeff Findley]

Post by JF Mezei

Post by Jeff Findley
True, but that's essentially still the state of the art today.
Composite layup machines have been around for decades.

Wasn't aware of that. If that is the case, then you are correct.

Post by Jeff Findley
fiber layup, so I'd count that as new, whenever it was first done. I'm
not a materials engineer, so I don't know when that would be for glass
fiber and aluminum.

Developped by/for Airbus as part of many years og R&D un mid/late 1990s
when Airbus wanted to make the A380 but knew it woudln't be economical
(too heavy) with current tech. It wasn't till they solved a number of
weight and landing gear problems that they could launch the project
formally.
BFR/BFS may have similar scalability problems since weight is also a big
issue. But they won't have to worry about landing pad being strong
enough for it since they can build their own.

Post by Jeff Findley
X-33 attempted to do just that. It failed due to the complex geometry.
BFR/BFS is sticking with traditional cylindrical tanks, which is a
proven geometry for carbon fiber composites. They're being pretty
conservative as far as their use of carbon fiber goes, IMHO.

Had forgotten about the odd shape for X33 tanks being reason for failure.

Post by Jeff Findley
From what I've read, they'll be sticking with traditional techniques to
minimize development risks. I fully expect them to cure it in an
autoclave.

Yet, that BFR all composite tank is at a scale nobody has productized
before. Just because they seem to have been able to build/test it
doesn't mean that it is "conventional" in design or using off-the-shelf
resin.

They already built the thing and it's stitting inside a tent at the
BFR/BFS production facility:

SpaceX moving fast on Mars rocket development, BFR tent spied with more
tooling

https://www.teslarati.com/spacex-bfr-tent-spy-shot-mars-rocket-tooling-
molds/

It's big, but others have build quite large autoclaves:

ASC Process Systems Manufactured the World's Largest Autoclave System.
http://www.aschome.com/index.php/en/products/control-systems/2-
uncategorised/327-world-s-largest-composites-autoclave

From above:

Inside working diameter: 30ft. (9.26M)
Inside working length: 76 ft. (23.5M)

From Orbital ATK's arsenal:

https://en.wikipedia.org/wiki/Castor_(rocket_stage)

Scroll down to Castor-600, which is to be used for OmegA:

Based on a 2-segment Space Shuttle SRB, the Castor 600 measures
860 inches (22 m) in length and 146.1 inches (3.71 m) in
diameter, and it weighs approximately 600,000 pounds (270,000
kg). Instead of using a D6AC steel case and PBAN binder like
the Space Shuttle SRB, it will instead use the technology
derived from the GEM motors which have carbon composite cases
and HTPB binder. The carbon composite design eliminates the
factory joint common on all Space Shuttle SRBs.

If Orbital ATK can made SRB casings out of carbon composites (very large
size and pressures inside an SRB casing), then making a few tanks for
BFR/BFS out of carbon composites will be a lot eaiser.

This stuff really isn't as uncommon as you think.

Jeff

[JF Mezei]

Post by Jeff Findley
They already built the thing and it's stitting inside a tent at the

Just because they already built it doesn't negate the potential for them
to have needed breaktrough to scale this not only for size but also
repeated cryo load/unload cycles.

Just because they built test articles using conventional stuff available
from yor local hardware store doesn't mean that the final product will
not be highly propriettary with new version of fibres and resin.

Quickly building one with available composites allows them to make
initial tests on strength and then do the fatique tests quickly, see
if/how it fails and then develop what is needed to make this long
lasting tanks.

The fact that SpaceX is tight lipped about how it built its tanks points
to them already beyond using already commercial available materials and
process. There is more to a picture of a mandrel in making a large
composite cylinder.

Also note: neither SpaceX nor orbital ATK have this in production yet.
Either could hit stumbling blocks on the way.

Using composite for room temperature + very hot SRBs is not the same as
a tank that goes from room temperature to very cold in cryo to very hot
once expose to sun in space.

Also, is Castor going to be re-usable?

[Fred J. McCall]

Post by JF Mezei

Post by Jeff Findley
They already built the thing and it's stitting inside a tent at the

Just because they already built it doesn't negate the potential for them
to have needed breaktrough to scale this not only for size but also
repeated cryo load/unload cycles.

Yes, they could always discover that magical unicorns are attracted to
it to shit on it and that breaks it, but having run full pressure
tests and burst tests that's pretty damned unlikely.

Post by JF Mezei
Just because they built test articles using conventional stuff available
from yor local hardware store doesn't mean that the final product will
not be highly propriettary with new version of fibres and resin.

Yes, because engineering organizations always build shit that isn't
representative of what they're actually building.

Post by JF Mezei
Quickly building one with available composites allows them to make
initial tests on strength and then do the fatique tests quickly, see
if/how it fails and then develop what is needed to make this long
lasting tanks.

Not how engineering works. Can you really be this clueless?

Post by JF Mezei
The fact that SpaceX is tight lipped about how it built its tanks points
to them already beyond using already commercial available materials and
process. There is more to a picture of a mandrel in making a large
composite cylinder.

Hogwash!

Post by JF Mezei
Also note: neither SpaceX nor orbital ATK have this in production yet.
Either could hit stumbling blocks on the way.

Yes, and monkeys might fly out your butt.

Post by JF Mezei
Using composite for room temperature + very hot SRBs is not the same as
a tank that goes from room temperature to very cold in cryo to very hot
once expose to sun in space.

What makes you think the case on an SRB gets all that hot? Tanks only
get exposed to sun in space if you plan on peeling the shell of the
spacecraft off. I don't know of any spacecraft that do that.

[JF Mezei]

Post by Fred J. McCall
Not how engineering works. Can you really be this clueless?

Engineering tries to PREDICT how a structure will behave.

Guess what? it is only a prediction whcih is why they have to do lots of
testing to validate the engineering.

Otherwise, they'd just build a totally new rocket with totally new
engines, bring it to the launchpad, add a very expensive payload, fuel
and press "GO" and be confident nothing will go wrong.

Did engineering predict the metal/composite tank problem when they
changed fueling sequence ?

Did SpaceX succeed on first go with its launches?
Did SpaceX succeed on first go with its landings?


Yes, they built a prototype of BFR tank. Yes, they filled it and it
worked. Yes, they filled it beyond that to measure at what presssure it
would break (and how it would fail).

But that in no way means they have a finished product. For instance,
when it broke when filled beyond limits, it may have broken in an
unforeseen way.

Just because the SpaceX PR made this look like a great success, it
doesn't mean that problems weren't found during those tests.

Whether those problems require just fine tuning of the layup to add a
few layers of fibres, or whether they may require major R&D to develop
new resin that widthstands the extremes over repeated load/unload of
cryos, I have no idea. But neither do you because SpaceX wouldn't reveal
that.

If building large cryo tanks have been so easy, and materials available
since the 1960s, surely it would have been done before. Why not used for
Shuttle? Why not used for all rockets built after Saturn 5?

[Jeff Findley]

Post by JF Mezei

Post by Fred J. McCall
Not how engineering works. Can you really be this clueless?

Engineering tries to PREDICT how a structure will behave.

<snip?

I snipped the rest of your rambling post. You really should stop
telling engineers how you think engineering works.

Also, you act like they've done zero cryogenic testing on this composite
cryogenic tank design. This is utterly false. Here is a cite from
Composites Manufacturing Magazine:

SpaceX Successfully Tests Carbon Fiber Tank for Mars Spaceship
Evan Milberg, November 29, 2016
http://compositesmanufacturingmagazine.com/2016/11/spacex-successfully-
tests-carbon-fiber-tank-mars-spaceship/

You seem to keep assuming SpaceX engineers don't perform any sort of
ground testing and just "wing it" every time they fly. The facts do not
support that assertion.

Note also that this article was from November 29, 2016. It's quite
likely SpaceX has performed other tests between then and now, nearly two
years later. But, since they're a private company, they don't *have* to
tell us anything, now do they?

Jeff

[JF Mezei]

Post by Jeff Findley
Also, you act like they've done zero cryogenic testing on this composite
cryogenic tank design. This is utterly false. Here is a cite from

I mentioned that they built one, filled it succesfully, then
destructively tested it to see at what pressure it failed. I did not
ignore this. The article you linked is older and doesn't mention the
destructive test SpaceX did (which I mentioned).

These tests do not mean the tank is ready. There are other tests they
need to do, in particulat measure how many fill/empty cycles can be made
before flaws start to appear. And if that number if below expectations,
fix the design to add longevity.

This is a normal part of development. Nothing nefarious about it. But
just because they did 2 tests doesn't mean that they did all the tests.

Post by Jeff Findley
You seem to keep assuming SpaceX engineers don't perform any sort of
ground testing and just "wing it" every time they fly. The facts do not
support that assertion.

I was responding to McCall who claimed engineers can build stuff that
works (in response to my arguments they need to test to validate the
designs and in doing so, can possibly find problems that need to be fixed.

[Fred J. McCall]

Post by JF Mezei

Post by Jeff Findley
Also, you act like they've done zero cryogenic testing on this composite
cryogenic tank design. This is utterly false. Here is a cite from

I mentioned that they built one, filled it succesfully, then
destructively tested it to see at what pressure it failed. I did not
ignore this. The article you linked is older and doesn't mention the
destructive test SpaceX did (which I mentioned).

You also claimed that what they built and tested wasn't representative
of what they intend to build as a final article and fly, which is just
a stupid assertion.

Post by JF Mezei
These tests do not mean the tank is ready. There are other tests they
need to do, in particulat measure how many fill/empty cycles can be made
before flaws start to appear. And if that number if below expectations,
fix the design to add longevity.
This is a normal part of development. Nothing nefarious about it. But
just because they did 2 tests doesn't mean that they did all the tests.

Just because they only told you about two tests doesn't mean they
didn't do any others.

Post by JF Mezei

Post by Jeff Findley
You seem to keep assuming SpaceX engineers don't perform any sort of
ground testing and just "wing it" every time they fly. The facts do not
support that assertion.

I was responding to McCall who claimed engineers can build stuff that
works (in response to my arguments they need to test to validate the
designs and in doing so, can possibly find problems that need to be fixed.

Apparently your deficiency in knowledge of engineering is only
surpassed by your defective English skills, since I said no such
thing. My responses were replies to your massively stupid assertion
that they just built any old tank and tested that without any idea at
all of what they're actually going to build.

[JF Mezei]

Post by Fred J. McCall
You also claimed that what they built and tested wasn't representative
of what they intend to build as a final article and fly, which is just
a stupid assertion.

I did no such thing. I claimed that it was not necessarily what the
final would be because during testing, they discovery problems that
require changes.

Post by Fred J. McCall
Just because they only told you about two tests doesn't mean they
didn't do any others.

And just because of that, you can't claim they performed those tests
succesfully either.

My point is that you can't claim "mission accomplished" on those tanks
just because of 2 tests that SpaceX chose to make public.

[Fred J. McCall]

Post by JF Mezei

Post by Fred J. McCall
You also claimed that what they built and tested wasn't representative
of what they intend to build as a final article and fly, which is just
a stupid assertion.

I did no such thing. I claimed that it was not necessarily what the
final would be because during testing, they discovery problems that
require changes.

Of course you did. You said that they built their test tank out of
existing resins using existing processes but that would not be what
they built the 'real' tank using.

Post by JF Mezei

Post by Fred J. McCall
Just because they only told you about two tests doesn't mean they
didn't do any others.

And just because of that, you can't claim they performed those tests
succesfully either.
My point is that you can't claim "mission accomplished" on those tanks
just because of 2 tests that SpaceX chose to make public.

They've made more than two of them public. Your perpetual
underinformed state is your personal problem.

[Fred J. McCall]

Post by JF Mezei

Post by Fred J. McCall
Not how engineering works. Can you really be this clueless?

Engineering tries to PREDICT how a structure will behave.

Like I said, not how engineering works. You really don't understand
any of this except in the most simplistic ways, do you?

<snip idiocy>

[Doc O'Leary]

For your reference, records indicate that

Post by Jeff Findley
2017usenet1.subsume.com says...

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
Sure, sure, Star Trek style transporters with infinite range. I'll get
right on that.

No, you won?t. But you apparently *will* use it as a straw man to avoid
actually addressing the likelihood that new technologies developed in
the future will change the economies of space launches. Hell, that?s
essentially what SpaceX is demonstrating today.

Bullshit. SpaceX is not demonstrating any new technologies. They've
combined existing technologies in novel ways to solve the problems
involved in building Merlin engines and Falcon launch vehicles. There
is zero new tech in them. If you believe differently, name a new
technology they're using in their engines, launch vehicles, Dragon, and
etc.

<Sigh> Of *course* there’s no “new technology” in *anything* that’s
in the world today. Your engineering mindset has you in a motivated
reasoning spiral. The fact remains that, over the course of time,
new technologies have been developed that have made their way into
space programs. SpaceX is taking advantage of some of those
technologies today. It is a safe bet that such innovations will occur
in the future, and somebody will take advantage of them.

[Fred J. McCall]

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
2017usenet1.subsume.com says...

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
Sure, sure, Star Trek style transporters with infinite range. I'll get
right on that.

No, you won?t. But you apparently *will* use it as a straw man to avoid
actually addressing the likelihood that new technologies developed in
the future will change the economies of space launches. Hell, that?s
essentially what SpaceX is demonstrating today.

Bullshit. SpaceX is not demonstrating any new technologies. They've
combined existing technologies in novel ways to solve the problems
involved in building Merlin engines and Falcon launch vehicles. There
is zero new tech in them. If you believe differently, name a new
technology they're using in their engines, launch vehicles, Dragon, and
etc.

<Sigh> Of *course* there’s no “new technology” in *anything* that’s
in the world today. Your engineering mindset has you in a motivated
reasoning spiral. The fact remains that, over the course of time,
new technologies have been developed that have made their way into
space programs. SpaceX is taking advantage of some of those
technologies today. It is a safe bet that such innovations will occur
in the future, and somebody will take advantage of them.

And it's an even safer bet that none of those 'new technologies' are
going to replace "throwing stuff aft to move forward". A space
elevator on Earth requires not 'new technology', but 'new physics'.

[JF Mezei]

Post by Fred J. McCall
And it's an even safer bet that none of those 'new technologies' are
going to replace "throwing stuff aft to move forward".

Now now. We already know we'll test drive warp drive in 2063. They've
even already made a movie about it. (and on same day, we meet the
Vulcans in northern USA (I think it was Montana).

Until then, the accelerate mass backwards" may remain primary mode of
propulsion, but there could still be much innovation in how you do it.


Out of curiosity, if you detonated an atomic bomb inside an engine bell
(assume engine bell is infinitely strong).


does f=ma stll apply in terms of the mass being limited to the mass of
the bomb? Or do many other factors kick in in a nuclear explosion
because mass doesn't remain constant?


Is knowledge enough today that would allow micro nuclear explosions that
can be focused in trhowing its mass backwards at very high speed? (aka:
regular micro explosions to slowly accelerate ship)

Or must one have critiocal mass of nuclear material to cause an exlosion
so the smallest explosioon that can happen is HUGE ?

[Fred J. McCall]

Post by JF Mezei

Post by Fred J. McCall
And it's an even safer bet that none of those 'new technologies' are
going to replace "throwing stuff aft to move forward".

Now now. We already know we'll test drive warp drive in 2063. They've
even already made a movie about it. (and on same day, we meet the
Vulcans in northern USA (I think it was Montana).

I'm sure that makes perfect sense to 'Doc'.

Post by JF Mezei
Until then, the accelerate mass backwards" may remain primary mode of
propulsion, but there could still be much innovation in how you do it.
Out of curiosity, if you detonated an atomic bomb inside an engine bell
(assume engine bell is infinitely strong).

Not how you want to do it.

Post by JF Mezei
does f=ma stll apply in terms of the mass being limited to the mass of
the bomb? Or do many other factors kick in in a nuclear explosion
because mass doesn't remain constant?

Pretty much yes, although you'd probably get a decent 'photon drive'
component.

Post by JF Mezei
Is knowledge enough today that would allow micro nuclear explosions that
regular micro explosions to slowly accelerate ship)

This technology was investigated over half a century ago. See?
Existing technology.

https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)

Post by JF Mezei
Or must one have critiocal mass of nuclear material to cause an exlosion
so the smallest explosioon that can happen is HUGE ?

Forty tons (the smallest bomb we built in the 1950's) is not
particularly 'huge'. In fact, it was regarded as too small for
anything but an orbital test program.

[Doc O'Leary]

For your reference, records indicate that

Post by JF Mezei
Is knowledge enough today that would allow micro nuclear explosions that
regular micro explosions to slowly accelerate ship)
Or must one have critiocal mass of nuclear material to cause an exlosion
so the smallest explosioon that can happen is HUGE ?

<https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)>

[Alain Fournier]

Post by Fred J. McCall

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
2017usenet1.subsume.com says...

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
Sure, sure, Star Trek style transporters with infinite range. I'll get
right on that.

No, you won?t. But you apparently *will* use it as a straw man to avoid
actually addressing the likelihood that new technologies developed in
the future will change the economies of space launches. Hell, that?s
essentially what SpaceX is demonstrating today.

Bullshit. SpaceX is not demonstrating any new technologies. They've
combined existing technologies in novel ways to solve the problems
involved in building Merlin engines and Falcon launch vehicles. There
is zero new tech in them. If you believe differently, name a new
technology they're using in their engines, launch vehicles, Dragon, and
etc.

<Sigh> Of *course* there’s no “new technology” in *anything* that’s
in the world today. Your engineering mindset has you in a motivated
reasoning spiral. The fact remains that, over the course of time,
new technologies have been developed that have made their way into
space programs. SpaceX is taking advantage of some of those
technologies today. It is a safe bet that such innovations will occur
in the future, and somebody will take advantage of them.

And it's an even safer bet that none of those 'new technologies' are
going to replace "throwing stuff aft to move forward". A space
elevator on Earth requires not 'new technology', but 'new physics'.

It would be possible to build a space elevator using materials available
today without any major new technology. But that wouldn't be economical.
Not even remotely close to being economical. New materials would be
needed to build a sane space elevator, but new physics isn't needed.

See for instance
http://space.nss.org/media/2000-Space-Elevator-NASA-CP210429.pdf


Alain Fournier

[Fred J. McCall]

Post by Alain Fournier

Post by Fred J. McCall

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
2017usenet1.subsume.com says...

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
Sure, sure, Star Trek style transporters with infinite range. I'll get
right on that.

No, you won?t. But you apparently *will* use it as a straw man to avoid
actually addressing the likelihood that new technologies developed in
the future will change the economies of space launches. Hell, that?s
essentially what SpaceX is demonstrating today.

Bullshit. SpaceX is not demonstrating any new technologies. They've
combined existing technologies in novel ways to solve the problems
involved in building Merlin engines and Falcon launch vehicles. There
is zero new tech in them. If you believe differently, name a new
technology they're using in their engines, launch vehicles, Dragon, and
etc.

<Sigh> Of *course* there’s no “new technology” in *anything* that’s
in the world today. Your engineering mindset has you in a motivated
reasoning spiral. The fact remains that, over the course of time,
new technologies have been developed that have made their way into
space programs. SpaceX is taking advantage of some of those
technologies today. It is a safe bet that such innovations will occur
in the future, and somebody will take advantage of them.

And it's an even safer bet that none of those 'new technologies' are
going to replace "throwing stuff aft to move forward". A space
elevator on Earth requires not 'new technology', but 'new physics'.

It would be possible to build a space elevator using materials available
today without any major new technology. But that wouldn't be economical.
Not even remotely close to being economical. New materials would be
needed to build a sane space elevator, but new physics isn't needed.
See for instance
http://space.nss.org/media/2000-Space-Elevator-NASA-CP210429.pdf

I recall reading at least some analyses that said that the tensile
strength required exceeded atomic forces (in other words, an
impossibly strong material).

[Alain Fournier]

Post by Fred J. McCall

Post by Alain Fournier

Post by Fred J. McCall

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
2017usenet1.subsume.com says...

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
Sure, sure, Star Trek style transporters with infinite range. I'll get
right on that.

No, you won?t. But you apparently *will* use it as a straw man to avoid
actually addressing the likelihood that new technologies developed in
the future will change the economies of space launches. Hell, that?s
essentially what SpaceX is demonstrating today.

Bullshit. SpaceX is not demonstrating any new technologies. They've
combined existing technologies in novel ways to solve the problems
involved in building Merlin engines and Falcon launch vehicles. There
is zero new tech in them. If you believe differently, name a new
technology they're using in their engines, launch vehicles, Dragon, and
etc.

<Sigh> Of *course* there’s no “new technology” in *anything* that’s
in the world today. Your engineering mindset has you in a motivated
reasoning spiral. The fact remains that, over the course of time,
new technologies have been developed that have made their way into
space programs. SpaceX is taking advantage of some of those
technologies today. It is a safe bet that such innovations will occur
in the future, and somebody will take advantage of them.

And it's an even safer bet that none of those 'new technologies' are
going to replace "throwing stuff aft to move forward". A space
elevator on Earth requires not 'new technology', but 'new physics'.

It would be possible to build a space elevator using materials available
today without any major new technology. But that wouldn't be economical.
Not even remotely close to being economical. New materials would be
needed to build a sane space elevator, but new physics isn't needed.
See for instance
http://space.nss.org/media/2000-Space-Elevator-NASA-CP210429.pdf

I recall reading at least some analyses that said that the tensile
strength required exceeded atomic forces (in other words, an
impossibly strong material).

Without having checked, I would guess that that applies for a non
tapered cable. But if you taper the cable, it is physically possible to
build a cable using several existing materials.


Alain Fournier

[Jeff Findley]

Post by Alain Fournier

Post by Fred J. McCall

Post by Alain Fournier
It would be possible to build a space elevator using materials available
today without any major new technology. But that wouldn't be economical.
Not even remotely close to being economical. New materials would be
needed to build a sane space elevator, but new physics isn't needed.
See for instance
http://space.nss.org/media/2000-Space-Elevator-NASA-CP210429.pdf

I recall reading at least some analyses that said that the tensile
strength required exceeded atomic forces (in other words, an
impossibly strong material).

Without having checked, I would guess that that applies for a non
tapered cable. But if you taper the cable, it is physically possible to
build a cable using several existing materials.

That's my understanding as well. Better materials would make a tapered
cable practical. Today's materials result in a very huge tapered cable
necessitating a huge counterweight making the whole thing impractical.

So, we're arguing about impossible versus impractical here. Either way,
it's not going to be built with today's materials.

Jeff

[Alain Fournier]

Post by Jeff Findley

Post by Alain Fournier

Post by Fred J. McCall

Post by Alain Fournier
It would be possible to build a space elevator using materials available
today without any major new technology. But that wouldn't be economical.
Not even remotely close to being economical. New materials would be
needed to build a sane space elevator, but new physics isn't needed.
See for instance
http://space.nss.org/media/2000-Space-Elevator-NASA-CP210429.pdf

I recall reading at least some analyses that said that the tensile
strength required exceeded atomic forces (in other words, an
impossibly strong material).

Without having checked, I would guess that that applies for a non
tapered cable. But if you taper the cable, it is physically possible to
build a cable using several existing materials.

That's my understanding as well. Better materials would make a tapered
cable practical. Today's materials result in a very huge tapered cable
necessitating a huge counterweight making the whole thing impractical.
So, we're arguing about impossible versus impractical here. Either way,
it's not going to be built with today's materials.

Yes. But I think I am a little less optimistic than you about it
becoming practical in the future. If we have fantastic materials in the
future, maybe an elevator will become more practical, but SpaceX is
likely to figure how to build fantastic rockets if you give them
fantastic materials. So if you can build an elevator that would seem
practical today, that elevator might compete with a rocket that can be
reused 1000 times between inspections AND have high orbital mass fraction.

It is possible that we find a way to build a practical cable but not
find any major improvement to rocket technology. But I wouldn't count
too much on that.

Of course maybe I just read too much into your sentence "Better
materials would make a tapered cable practical."


Alain Fournier

[Sergio]

Post by Alain Fournier

Post by Alain Fournier

Post by Fred J. McCall

Post by Alain Fournier
It would be possible to build a space elevator using materials available
today without any major new technology. But that wouldn't be economical.
Not even remotely close to being economical. New materials would be
needed to build a sane space elevator, but new physics isn't needed.
See for instance
http://space.nss.org/media/2000-Space-Elevator-NASA-CP210429.pdf

I recall reading at least some analyses that said that the tensile
strength required exceeded atomic forces (in other words, an
impossibly strong material).

Without having checked, I would guess that that applies for a non
tapered cable. But if you taper the cable, it is physically possible to
build a cable using several existing materials.

That's my understanding as well.  Better materials would make a tapered
cable practical.  Today's materials result in a very huge tapered cable
necessitating a huge counterweight making the whole thing impractical.
So, we're arguing about impossible versus impractical here.  Either way,
it's not going to be built with today's materials.

Yes. But I think I am a little less optimistic than you about it
becoming practical in the future. If we have fantastic materials in the
future, maybe an elevator will become more practical, but SpaceX is
likely to figure how to build fantastic rockets if you give them
fantastic materials. So if you can build an elevator that would seem
practical today, that elevator might compete with a rocket that can be
reused 1000 times between inspections AND have high orbital mass fraction.
It is possible that we find a way to build a practical cable but not
find any major improvement to rocket technology. But I wouldn't count
too much on that.
Of course maybe I just read too much into your sentence "Better
materials would make a tapered cable practical."
Alain Fournier

how about a Space Slingshot ?

[Alain Fournier]

Post by Sergio

Post by Alain Fournier

Post by Alain Fournier

Post by Fred J. McCall

Post by Alain Fournier
It would be possible to build a space elevator using materials available
today without any major new technology. But that wouldn't be economical.
Not even remotely close to being economical. New materials would be
needed to build a sane space elevator, but new physics isn't needed.
See for instance
http://space.nss.org/media/2000-Space-Elevator-NASA-CP210429.pdf

I recall reading at least some analyses that said that the tensile
strength required exceeded atomic forces (in other words, an
impossibly strong material).

Without having checked, I would guess that that applies for a non
tapered cable. But if you taper the cable, it is physically possible to
build a cable using several existing materials.

That's my understanding as well.  Better materials would make a tapered
cable practical.  Today's materials result in a very huge tapered cable
necessitating a huge counterweight making the whole thing impractical.
So, we're arguing about impossible versus impractical here.  Either way,
it's not going to be built with today's materials.

Yes. But I think I am a little less optimistic than you about it
becoming practical in the future. If we have fantastic materials in the
future, maybe an elevator will become more practical, but SpaceX is
likely to figure how to build fantastic rockets if you give them
fantastic materials. So if you can build an elevator that would seem
practical today, that elevator might compete with a rocket that can be
reused 1000 times between inspections AND have high orbital mass fraction.
It is possible that we find a way to build a practical cable but not
find any major improvement to rocket technology. But I wouldn't count
too much on that.
Of course maybe I just read too much into your sentence "Better
materials would make a tapered cable practical."
Alain Fournier

how about a Space Slingshot ?

What do you mean by Space Slingshot?


Alain Fournier

[Jeff Findley]

Post by Sergio
how about a Space Slingshot ?

A fool and his money are soon parted.

They're not getting enough money to actually develop and build the
thing. They're raised what $40 million or something? They'll need a
hell of a lot more than that to turn their design into a reality.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.

[Alain Fournier]

Post by Jeff Findley

Post by Sergio
how about a Space Slingshot ?

A fool and his money are soon parted.
They're not getting enough money to actually develop and build the
thing. They're raised what $40 million or something? They'll need a
hell of a lot more than that to turn their design into a reality.

Are you two talking about SpinLaunch? If no, what do you mean by Space
Slingshot?


Alain Fournier

[Jeff Findley]

Post by Alain Fournier

Post by Jeff Findley

Post by Sergio
how about a Space Slingshot ?

A fool and his money are soon parted.
They're not getting enough money to actually develop and build the
thing. They're raised what $40 million or something? They'll need a
hell of a lot more than that to turn their design into a reality.

Are you two talking about SpinLaunch? If no, what do you mean by Space
Slingshot?

That was my guess. I personally don't think SpinLaunch is viable, at
least not without a heck of a lot of development. G loads will be
pretty crazy, so you can't use it for much except bulk cargo.

Jeff

[Alain Fournier]

Post by Jeff Findley

Post by Alain Fournier

Post by Jeff Findley

Post by Sergio
how about a Space Slingshot ?

A fool and his money are soon parted.
They're not getting enough money to actually develop and build the
thing. They're raised what $40 million or something? They'll need a
hell of a lot more than that to turn their design into a reality.

Are you two talking about SpinLaunch? If no, what do you mean by Space
Slingshot?

That was my guess. I personally don't think SpinLaunch is viable, at
least not without a heck of a lot of development. G loads will be
pretty crazy, so you can't use it for much except bulk cargo.

On Feb/25/2018 at 11:32 AM, (In sci.space.policy) I wrote:
"I might be wrong but I suspect those proposing SpinLaunch are aware of
the problems. Their business plan is probably more about collecting
investors money than about putting anything in orbit."

I haven't seen anything since that would make me change my mind about
that. So they aren't going to get any investment money from you and I.


Alain Fournier

[Mike Van Pelt]

Post by Sergio
how about a Space Slingshot ?

Do you mean a rotating skyhook?

Some of those ideas are ... intriguing. And have much less
stringent requirements on materials.

[JF Mezei]

Post by Alain Fournier
Yes. But I think I am a little less optimistic than you about it
becoming practical in the future. If we have fantastic materials in the
future, maybe an elevator will become more practical,

Apart from lifting geostationary satellites to just below orbit and then
let them use their own thrusters to position to their assigned
slot/longitude, what other use would a space elevator have ?

[Fred J. McCall]

Post by JF Mezei

Post by Alain Fournier
Yes. But I think I am a little less optimistic than you about it
becoming practical in the future. If we have fantastic materials in the
future, maybe an elevator will become more practical,

Apart from lifting geostationary satellites to just below orbit and then
let them use their own thrusters to position to their assigned
slot/longitude, what other use would a space elevator have ?

You go above the GEO point on the cable and get flung on
interplanetary trajectories.

[Alain Fournier]

Post by Fred J. McCall

Post by JF Mezei

Post by Alain Fournier
Yes. But I think I am a little less optimistic than you about it
becoming practical in the future. If we have fantastic materials in the
future, maybe an elevator will become more practical,

Apart from lifting geostationary satellites to just below orbit and then
let them use their own thrusters to position to their assigned
slot/longitude, what other use would a space elevator have ?

You go above the GEO point on the cable and get flung on
interplanetary trajectories.

Yes!

You would also likely put at least one cable above GEO rotating in a
plane perpendicular to the main cable. So you can give an extra push for
interplanetary trajectories and to fine tune in which direction you
depart for said trajectories.

You can also jump off at an altitude of about 15000 km (that figure is
from the top of my head, it might be more or might be less). From there
after a few passes of aero-braking you can reach LEO with very small
thrusters.

For polar orbits, you use the rotating cable above GEO mentioned above.
But instead of using it for extra push you get off while it is
subtracting some speed but not quite in the direction of rotation of the
cable. So you subtract some speed in the direction of rotation of the
cable and give some speed in the north-south axis. You then use
aero-braking again to lower apogee, and a small thruster to raise
perigee. Note however that using the elevator to reach polar orbits in
this way isn't obvious. You would want a long and fast rotating cable
and you would want it far above GEO, it might not be practical to do so.

Building an elevator, with current technologies, is outrageously
expensive. But if you have one, it can be very useful.


Alain Fournier

[Sergio]

Post by Alain Fournier

Post by Fred J. McCall

Post by JF Mezei

Post by Alain Fournier
Yes. But I think I am a little less optimistic than you about it
becoming practical in the future. If we have fantastic materials in the
future, maybe an elevator will become more practical,

Apart from lifting geostationary satellites to just below orbit and then
let them use their own thrusters to position to their assigned
slot/longitude, what other use would a space elevator have ?

You go above the GEO point on the cable and get flung on
interplanetary trajectories.

Yes!
You would also likely put at least one cable above GEO rotating in a
plane perpendicular to the main cable. So you can give an extra push for
interplanetary trajectories and to fine tune in which direction you
depart for said trajectories.
You can also jump off at an altitude of about 15000 km (that figure is
from the top of my head, it might be more or might be less). From there
after a few passes of aero-braking you can reach LEO with very small
thrusters.
For polar orbits, you use the rotating cable above GEO mentioned above.
But instead of using it for extra push you get off while it is
subtracting some speed but not quite in the direction of rotation of the
cable. So you subtract some speed in the direction of rotation of the
cable and give some speed in the north-south axis. You then use
aero-braking again to lower apogee, and a small thruster to raise
perigee. Note however that using the elevator to reach polar orbits in
this way isn't obvious. You would want a long and fast rotating cable
and you would want it far above GEO, it might not be practical to do so.
Building an elevator, with current technologies, is outrageously
expensive. But if you have one, it can be very useful.

we don't have one, and never will. It is a joke among Engineers.

What would is the monthly insurance payment for it? if it fell over ?

how many miles would the top swing back and forth ?

How much sideways force is pushed on it by a 20 mph wind ?

how much does one guy wire weigh ? (assume 20,000 km elevator height)

how much does one copper cable weigh if moving 200 amps ?

What voltage is needed at the ground to feed the copper wires ? assume
500 V AC needed at the top.

How much does the tower weigh counting only the copper wires, main
cable, and guy wires ?

Post by Alain Fournier
Alain Fournier

[Alain Fournier]

Post by Sergio

Post by Alain Fournier

Post by Fred J. McCall

Post by JF Mezei

Post by Alain Fournier
Yes. But I think I am a little less optimistic than you about it
becoming practical in the future. If we have fantastic materials in the
future, maybe an elevator will become more practical,

Apart from lifting geostationary satellites to just below orbit and then
let them use their own thrusters to position to their assigned
slot/longitude, what other use would a space elevator have ?

You go above the GEO point on the cable and get flung on
interplanetary trajectories.

Yes!
You would also likely put at least one cable above GEO rotating in a
plane perpendicular to the main cable. So you can give an extra push for
interplanetary trajectories and to fine tune in which direction you
depart for said trajectories.
You can also jump off at an altitude of about 15000 km (that figure is
from the top of my head, it might be more or might be less). From there
after a few passes of aero-braking you can reach LEO with very small
thrusters.
For polar orbits, you use the rotating cable above GEO mentioned above.
But instead of using it for extra push you get off while it is
subtracting some speed but not quite in the direction of rotation of the
cable. So you subtract some speed in the direction of rotation of the
cable and give some speed in the north-south axis. You then use
aero-braking again to lower apogee, and a small thruster to raise
perigee. Note however that using the elevator to reach polar orbits in
this way isn't obvious. You would want a long and fast rotating cable
and you would want it far above GEO, it might not be practical to do so.
Building an elevator, with current technologies, is outrageously
expensive. But if you have one, it can be very useful.

we don't have one, and never will. It is a joke among Engineers.
What would is the monthly insurance payment for it? if it fell over ?

You put the cable on an east coast. You also put a system to cut the
cable at something like 10000 km high. If the cable breaks below that
10000 km the upper part doesn't fall it goes up, the bottom part falls
in the ocean, where it isn't likely to cause damage. If the cable breaks
higher than 10000 km, you cut it at 10000 km, the bottom 10000 km falls
once again in the ocean. The two other parts won't fall to the ground,
the lower part will probably be in an elliptical orbit, the higher part
might be in an escape trajectory. So the damage from a cable breaking
doesn't have to be high. It might be a little difficult to explain that
to an insurance company, but if you can pay for the cable, you should be
able to cover the damages.

Post by Sergio
how many miles would the top swing back and forth ?

Why do you care?

Post by Sergio
How much sideways force is pushed on it by a 20 mph wind ?

Why do you care?

Post by Sergio
how much does one guy wire weigh ? (assume 20,000 km elevator height)

Why would you put a guy wire? Don't assume 20,000 km elevator height,
assume 70,000 km, you want the top of the cable to pull up the bottom of
the cable, so you have to go beyond GEO height.

Post by Sergio
how much does one copper cable weigh if moving 200 amps ?

Don't put a copper cable. Send energy to the climber using some kind of
beamed energy. (A laser on the ground, maybe another one in
geosynchronous orbit, and photocells on the climber to convert back to
electricity. Or something of that kind.)

Post by Sergio
What voltage is needed at the ground to feed the copper wires ? assume
500 V AC needed at the top.
How much does the tower weigh counting only the copper wires, main
cable, and guy wires ?

The copper wires and guy wires are nonexistent and therefore weigh
nothing. As for the main cable, it weighs way too much. That is why I
said in the message to which you are replying that "Building an
elevator, with current technologies, is outrageously expensive." I don't
think we will ever have one.


Alain Fournier

[Fred J. McCall]

Post by Alain Fournier
You put the cable on an east coast.

Uh, do you mean west coast? If the thing falls isn't it going to lay
out along the direction of spin, which means it falls to the west.

[Sergio]

Post by Alain Fournier

Post by Alain Fournier

Post by Fred J. McCall

Post by JF Mezei

Post by Alain Fournier
Yes. But I think I am a little less optimistic than you about it
becoming practical in the future. If we have fantastic materials in the
future, maybe an elevator will become more practical,

Apart from lifting geostationary satellites to just below orbit and then
let them use their own thrusters to position to their assigned
slot/longitude, what other use would a space elevator have ?

You go above the GEO point on the cable and get flung on
interplanetary trajectories.

Yes!
You would also likely put at least one cable above GEO rotating in a
plane perpendicular to the main cable. So you can give an extra push for
interplanetary trajectories and to fine tune in which direction you
depart for said trajectories.
You can also jump off at an altitude of about 15000 km (that figure is
from the top of my head, it might be more or might be less). From there
after a few passes of aero-braking you can reach LEO with very small
thrusters.
For polar orbits, you use the rotating cable above GEO mentioned above.
But instead of using it for extra push you get off while it is
subtracting some speed but not quite in the direction of rotation of the
cable. So you subtract some speed in the direction of rotation of the
cable and give some speed in the north-south axis. You then use
aero-braking again to lower apogee, and a small thruster to raise
perigee. Note however that using the elevator to reach polar orbits in
this way isn't obvious. You would want a long and fast rotating cable
and you would want it far above GEO, it might not be practical to do so.
Building an elevator, with current technologies, is outrageously
expensive. But if you have one, it can be very useful.

we don't have one, and never will.  It is a joke among Engineers.
What would is the monthly insurance payment for it?  if it fell over ?

You put the cable on an east coast. You also put a system to cut the
cable at something like 10000 km high. If the cable breaks below that
10000 km the upper part doesn't fall it goes up, the bottom part falls
in the ocean, where it isn't likely to cause damage. If the cable breaks
higher than 10000 km, you cut it at 10000 km, the bottom 10000 km falls
once again in the ocean. The two other parts won't fall to the ground,
the lower part will probably be in an elliptical orbit, the higher part
might be in an escape trajectory. So the damage from a cable breaking
doesn't have to be high. It might be a little difficult to explain that
to an insurance company, but if you can pay for the cable, you should be
able to cover the damages.

how much does 10,000 of cable weigh? 100,000 #
the center of gravity is directly over the support, so you have 100,000#
of steel cable crashing onto it.

nothing will go into orbit as the accelleration vector is stright down,
gravity.

Post by Alain Fournier

how many miles would the top swing back and forth ?

Why do you care?

I asking to see if you know what you are talking about. 20,000 km is
12,427 miles, if you support the tower it will swing at least 2 degrees
sin 2 degrees = 0.035 times 12427 = *434 miles*

does the tip swinging wider than most states bother you ??

Post by Alain Fournier

How much sideways force is pushed on it by a 20 mph wind ?

Why do you care?

...to evaporate your imagination with facts.

Post by Alain Fournier

how much does one guy wire weigh ? (assume 20,000 km elevator height)

Why would you put a guy wire? Don't assume 20,000 km elevator height,
assume 70,000 km, you want the top of the cable to pull up the bottom of
the cable, so you have to go beyond GEO height.

so what is the weight of 70,000 km of cable to support 500# ?

[there is no cable that will support itself 70,000 km, darling)

Post by Alain Fournier

how much does one copper cable weigh if moving 200 amps ?

Don't put a copper cable. Send energy to the climber using some kind of
beamed energy. (A laser on the ground, maybe another one in
geosynchronous orbit, and photocells on the climber to convert back to
electricity. Or something of that kind.)

Use McGinn's patented plasma's and water vapor it up. What happens
when you use a 1000 watt laser to shoot power to it ? the beam heats up
the air and defocuses the beam and the power splinters out, the power
does not get there.

there is no know laser that can meet the dispersion requirements either
(google dispersion laser)

Post by Alain Fournier

What voltage is needed at the ground to feed the copper wires ?  assume
500 V AC needed at the top.
How much does the tower weigh counting only the copper wires, main
cable, and guy wires ?

The copper wires and guy wires are nonexistent and therefore weigh
nothing. As for the main cable, it weighs way too much. That is why I
said in the message to which you are replying that "Building an
elevator, with current technologies, is outrageously expensive." I don't
think we will ever have one.

it is joke bate by Engineers,

Post by Alain Fournier
Alain Fournier

[Fred J. McCall]

Post by Sergio

Post by Alain Fournier

Post by Alain Fournier

Post by Fred J. McCall

Post by JF Mezei

Post by Alain Fournier
Yes. But I think I am a little less optimistic than you about it
becoming practical in the future. If we have fantastic materials in the
future, maybe an elevator will become more practical,

Apart from lifting geostationary satellites to just below orbit and then
let them use their own thrusters to position to their assigned
slot/longitude, what other use would a space elevator have ?

You go above the GEO point on the cable and get flung on
interplanetary trajectories.

Yes!
You would also likely put at least one cable above GEO rotating in a
plane perpendicular to the main cable. So you can give an extra push for
interplanetary trajectories and to fine tune in which direction you
depart for said trajectories.
You can also jump off at an altitude of about 15000 km (that figure is
from the top of my head, it might be more or might be less). From there
after a few passes of aero-braking you can reach LEO with very small
thrusters.
For polar orbits, you use the rotating cable above GEO mentioned above.
But instead of using it for extra push you get off while it is
subtracting some speed but not quite in the direction of rotation of the
cable. So you subtract some speed in the direction of rotation of the
cable and give some speed in the north-south axis. You then use
aero-braking again to lower apogee, and a small thruster to raise
perigee. Note however that using the elevator to reach polar orbits in
this way isn't obvious. You would want a long and fast rotating cable
and you would want it far above GEO, it might not be practical to do so.
Building an elevator, with current technologies, is outrageously
expensive. But if you have one, it can be very useful.

we don't have one, and never will.  It is a joke among Engineers.
What would is the monthly insurance payment for it?  if it fell over ?

You put the cable on an east coast. You also put a system to cut the
cable at something like 10000 km high. If the cable breaks below that
10000 km the upper part doesn't fall it goes up, the bottom part falls
in the ocean, where it isn't likely to cause damage. If the cable breaks
higher than 10000 km, you cut it at 10000 km, the bottom 10000 km falls
once again in the ocean. The two other parts won't fall to the ground,
the lower part will probably be in an elliptical orbit, the higher part
might be in an escape trajectory. So the damage from a cable breaking
doesn't have to be high. It might be a little difficult to explain that
to an insurance company, but if you can pay for the cable, you should be
able to cover the damages.

how much does 10,000 of cable weigh? 100,000 #
the center of gravity is directly over the support, so you have 100,000#
of steel cable crashing onto it.

Nope. The Earth spins, you know. And STEEL? That's cute.

Post by Sergio
nothing will go into orbit as the accelleration vector is stright down,
gravity.

Well, no. When whole, the cable is under tension, not compression.
Remove weight from the bottom or break the tether point and it goes UP
above the break, not down.

Post by Sergio

Post by Alain Fournier

how many miles would the top swing back and forth ?

Why do you care?

I asking to see if you know what you are talking about. 20,000 km is
12,427 miles, if you support the tower it will swing at least 2 degrees
sin 2 degrees = 0.035 times 12427 = *434 miles*
does the tip swinging wider than most states bother you ??

You're not smart enough to be asking questions. It's not a 'tower'.

Post by Sergio

Post by Alain Fournier

How much sideways force is pushed on it by a 20 mph wind ?

Why do you care?

...to evaporate your imagination with facts.

That would be refreshing. When are you going to start?

Post by Sergio

Post by Alain Fournier

how much does one guy wire weigh ? (assume 20,000 km elevator height)

Why would you put a guy wire? Don't assume 20,000 km elevator height,
assume 70,000 km, you want the top of the cable to pull up the bottom of
the cable, so you have to go beyond GEO height.

so what is the weight of 70,000 km of cable to support 500# ?

That rather depends on what it's made of.

Post by Sergio
[there is no cable that will support itself 70,000 km, darling)

There is no cable that will support its own weight like that YET. You
really need to STFU until you educate yourself.

Post by Sergio

Post by Alain Fournier

how much does one copper cable weigh if moving 200 amps ?

Don't put a copper cable. Send energy to the climber using some kind of
beamed energy. (A laser on the ground, maybe another one in
geosynchronous orbit, and photocells on the climber to convert back to
electricity. Or something of that kind.)

Use McGinn's patented plasma's and water vapor it up. What happens
when you use a 1000 watt laser to shoot power to it ? the beam heats up
the air and defocuses the beam and the power splinters out, the power
does not get there.
there is no know laser that can meet the dispersion requirements either
(google dispersion laser)

Hogwash.

Post by Sergio

Post by Alain Fournier

What voltage is needed at the ground to feed the copper wires ?  assume
500 V AC needed at the top.
How much does the tower weigh counting only the copper wires, main
cable, and guy wires ?

The copper wires and guy wires are nonexistent and therefore weigh
nothing. As for the main cable, it weighs way too much. That is why I
said in the message to which you are replying that "Building an
elevator, with current technologies, is outrageously expensive." I don't
think we will ever have one.

it is joke bate by Engineers,

You wouldn't know an engineer if you tripped over one.

[Sergio]

Post by Fred J. McCall

Post by Sergio

Post by Alain Fournier

Post by Alain Fournier

Post by Fred J. McCall

Post by JF Mezei

Post by Alain Fournier
Yes. But I think I am a little less optimistic than you about it
becoming practical in the future. If we have fantastic materials in the
future, maybe an elevator will become more practical,

Apart from lifting geostationary satellites to just below orbit and then
let them use their own thrusters to position to their assigned
slot/longitude, what other use would a space elevator have ?

You go above the GEO point on the cable and get flung on
interplanetary trajectories.

Yes!
You would also likely put at least one cable above GEO rotating in a
plane perpendicular to the main cable. So you can give an extra push for
interplanetary trajectories and to fine tune in which direction you
depart for said trajectories.
You can also jump off at an altitude of about 15000 km (that figure is
from the top of my head, it might be more or might be less). From there
after a few passes of aero-braking you can reach LEO with very small
thrusters.
For polar orbits, you use the rotating cable above GEO mentioned above.
But instead of using it for extra push you get off while it is
subtracting some speed but not quite in the direction of rotation of the
cable. So you subtract some speed in the direction of rotation of the
cable and give some speed in the north-south axis. You then use
aero-braking again to lower apogee, and a small thruster to raise
perigee. Note however that using the elevator to reach polar orbits in
this way isn't obvious. You would want a long and fast rotating cable
and you would want it far above GEO, it might not be practical to do so.
Building an elevator, with current technologies, is outrageously
expensive. But if you have one, it can be very useful.

we don't have one, and never will.  It is a joke among Engineers.
What would is the monthly insurance payment for it?  if it fell over ?

You put the cable on an east coast. You also put a system to cut the
cable at something like 10000 km high. If the cable breaks below that
10000 km the upper part doesn't fall it goes up, the bottom part falls
in the ocean, where it isn't likely to cause damage. If the cable breaks
higher than 10000 km, you cut it at 10000 km, the bottom 10000 km falls
once again in the ocean. The two other parts won't fall to the ground,
the lower part will probably be in an elliptical orbit, the higher part
might be in an escape trajectory. So the damage from a cable breaking
doesn't have to be high. It might be a little difficult to explain that
to an insurance company, but if you can pay for the cable, you should be
able to cover the damages.

how much does 10,000 of cable weigh? 100,000 #
the center of gravity is directly over the support, so you have 100,000#
of steel cable crashing onto it.

Nope. The Earth spins, you know. And STEEL? That's cute.

earth spin is red herring, do the math.
what else are you going to use besides steel ?
NOTHING can support its own weight of 10,000 km of it.

go ahead, NAME what you propose to use.

Post by Fred J. McCall

Post by Sergio
nothing will go into orbit as the accelleration vector is stright down,
gravity.

Well, no. When whole, the cable is under tension, not compression.
Remove weight from the bottom or break the tether point and it goes UP
above the break, not down.

no, gravity wins over whatever transitory events.

Post by Fred J. McCall

Post by Sergio

Post by Alain Fournier

how many miles would the top swing back and forth ?

Why do you care?

I asking to see if you know what you are talking about. 20,000 km is
12,427 miles, if you support the tower it will swing at least 2 degrees
sin 2 degrees = 0.035 times 12427 = *434 miles*
does the tip swinging wider than most states bother you ??

You're not smart enough to be asking questions. It's not a 'tower'.

what do you propose ?

Post by Fred J. McCall

Post by Sergio

Post by Alain Fournier

How much sideways force is pushed on it by a 20 mph wind ?

Why do you care?

...to evaporate your imagination with facts.

That would be refreshing. When are you going to start?

what are you proposing ?

Post by Fred J. McCall

Post by Sergio

Post by Alain Fournier

how much does one guy wire weigh ? (assume 20,000 km elevator height)

Why would you put a guy wire? Don't assume 20,000 km elevator height,
assume 70,000 km, you want the top of the cable to pull up the bottom of
the cable, so you have to go beyond GEO height.

so what is the weight of 70,000 km of cable to support 500# ?

That rather depends on what it's made of.

you wont name anything, because it is all too heavy.

got anything ?

Post by Fred J. McCall

Post by Sergio
[there is no cable that will support itself 70,000 km, darling)

There is no cable that will support its own weight like that YET. You
really need to STFU until you educate yourself.

and there never will be. do the math. check the materials, imaginarium
won't work either.

Post by Fred J. McCall

Post by Sergio

Post by Alain Fournier

how much does one copper cable weigh if moving 200 amps ?

Don't put a copper cable. Send energy to the climber using some kind of
beamed energy. (A laser on the ground, maybe another one in
geosynchronous orbit, and photocells on the climber to convert back to
electricity. Or something of that kind.)

Use McGinn's patented plasma's and water vapor it up. What happens
when you use a 1000 watt laser to shoot power to it ? the beam heats up
the air and defocuses the beam and the power splinters out, the power
does not get there.
there is no know laser that can meet the dispersion requirements either
(google dispersion laser)

Hogwash.

afraid to google for it ? why doen't the army shoot down missles with
lasers ? -- dispersion and defocusing --

Post by Fred J. McCall

Post by Sergio

Post by Alain Fournier

What voltage is needed at the ground to feed the copper wires ?  assume
500 V AC needed at the top.
How much does the tower weigh counting only the copper wires, main
cable, and guy wires ?

The copper wires and guy wires are nonexistent and therefore weigh
nothing. As for the main cable, it weighs way too much. That is why I
said in the message to which you are replying that "Building an
elevator, with current technologies, is outrageously expensive." I don't
think we will ever have one.

it is joke bate by Engineers,

You wouldn't know an engineer if you tripped over one.

and you have no real facts for your "space elevator".

[Fred J. McCall]

Post by Sergio

Post by Fred J. McCall

Post by Sergio

Post by Alain Fournier

Post by Alain Fournier

Post by Fred J. McCall

Post by JF Mezei

Post by Alain Fournier
Yes. But I think I am a little less optimistic than you about it
becoming practical in the future. If we have fantastic materials in the
future, maybe an elevator will become more practical,

Apart from lifting geostationary satellites to just below orbit and then
let them use their own thrusters to position to their assigned
slot/longitude, what other use would a space elevator have ?

You go above the GEO point on the cable and get flung on
interplanetary trajectories.

Yes!
You would also likely put at least one cable above GEO rotating in a
plane perpendicular to the main cable. So you can give an extra push for
interplanetary trajectories and to fine tune in which direction you
depart for said trajectories.
You can also jump off at an altitude of about 15000 km (that figure is
from the top of my head, it might be more or might be less). From there
after a few passes of aero-braking you can reach LEO with very small
thrusters.
For polar orbits, you use the rotating cable above GEO mentioned above.
But instead of using it for extra push you get off while it is
subtracting some speed but not quite in the direction of rotation of the
cable. So you subtract some speed in the direction of rotation of the
cable and give some speed in the north-south axis. You then use
aero-braking again to lower apogee, and a small thruster to raise
perigee. Note however that using the elevator to reach polar orbits in
this way isn't obvious. You would want a long and fast rotating cable
and you would want it far above GEO, it might not be practical to do so.
Building an elevator, with current technologies, is outrageously
expensive. But if you have one, it can be very useful.

we don't have one, and never will.  It is a joke among Engineers.
What would is the monthly insurance payment for it?  if it fell over ?

You put the cable on an east coast. You also put a system to cut the
cable at something like 10000 km high. If the cable breaks below that
10000 km the upper part doesn't fall it goes up, the bottom part falls
in the ocean, where it isn't likely to cause damage. If the cable breaks
higher than 10000 km, you cut it at 10000 km, the bottom 10000 km falls
once again in the ocean. The two other parts won't fall to the ground,
the lower part will probably be in an elliptical orbit, the higher part
might be in an escape trajectory. So the damage from a cable breaking
doesn't have to be high. It might be a little difficult to explain that
to an insurance company, but if you can pay for the cable, you should be
able to cover the damages.

how much does 10,000 of cable weigh? 100,000 #
the center of gravity is directly over the support, so you have 100,000#
of steel cable crashing onto it.

Nope. The Earth spins, you know. And STEEL? That's cute.

earth spin is red herring, do the math.

You do the math.

Post by Sergio
what else are you going to use besides steel ?

Almost anything.

Post by Sergio
NOTHING can support its own weight of 10,000 km of it.

False. You really need to do some research.

Post by Sergio
go ahead, NAME what you propose to use.

Carbon nanotubes.

Post by Sergio

Post by Fred J. McCall

Post by Sergio
nothing will go into orbit as the accelleration vector is stright down,
gravity.

Well, no. When whole, the cable is under tension, not compression.
Remove weight from the bottom or break the tether point and it goes UP
above the break, not down.

no, gravity wins over whatever transitory events.

Don't look now, but I think you just claimed that space satellites and
the Moon are impossible.

Post by Sergio

Post by Fred J. McCall

Post by Sergio

Post by Alain Fournier

how many miles would the top swing back and forth ?

Why do you care?

I asking to see if you know what you are talking about. 20,000 km is
12,427 miles, if you support the tower it will swing at least 2 degrees
sin 2 degrees = 0.035 times 12427 = *434 miles*
does the tip swinging wider than most states bother you ??

You're not smart enough to be asking questions. It's not a 'tower'.

what do you propose ?

And in that question you demonstrate just how clueless you are.

Post by Sergio

Post by Fred J. McCall

Post by Sergio

Post by Alain Fournier

How much sideways force is pushed on it by a 20 mph wind ?

Why do you care?

...to evaporate your imagination with facts.

That would be refreshing. When are you going to start?

what are you proposing ?

I'm proposing you start making sense (but I'm not holding my breath).

Post by Sergio

Post by Fred J. McCall

Post by Sergio

Post by Alain Fournier

how much does one guy wire weigh ? (assume 20,000 km elevator height)

Why would you put a guy wire? Don't assume 20,000 km elevator height,
assume 70,000 km, you want the top of the cable to pull up the bottom of
the cable, so you have to go beyond GEO height.

so what is the weight of 70,000 km of cable to support 500# ?

That rather depends on what it's made of.

you wont name anything, because it is all too heavy.
got anything ?

Jesus, go learn something. Right now you just sound abysmally stupid.

Post by Sergio

Post by Fred J. McCall

Post by Sergio
[there is no cable that will support itself 70,000 km, darling)

There is no cable that will support its own weight like that YET. You
really need to STFU until you educate yourself.

and there never will be. do the math. check the materials, imaginarium
won't work either.

I'm sorry you're clueless.

Post by Sergio

Post by Fred J. McCall

Post by Sergio

Post by Alain Fournier

how much does one copper cable weigh if moving 200 amps ?

Don't put a copper cable. Send energy to the climber using some kind of
beamed energy. (A laser on the ground, maybe another one in
geosynchronous orbit, and photocells on the climber to convert back to
electricity. Or something of that kind.)

Use McGinn's patented plasma's and water vapor it up. What happens
when you use a 1000 watt laser to shoot power to it ? the beam heats up
the air and defocuses the beam and the power splinters out, the power
does not get there.
there is no know laser that can meet the dispersion requirements either
(google dispersion laser)

Hogwash.

afraid to google for it ? why doen't the army shoot down missles with
lasers ? -- dispersion and defocusing --

Uh, you haven't been paying attention, have you?

Post by Sergio

Post by Fred J. McCall

Post by Sergio

Post by Alain Fournier

What voltage is needed at the ground to feed the copper wires ?  assume
500 V AC needed at the top.
How much does the tower weigh counting only the copper wires, main
cable, and guy wires ?

The copper wires and guy wires are nonexistent and therefore weigh
nothing. As for the main cable, it weighs way too much. That is why I
said in the message to which you are replying that "Building an
elevator, with current technologies, is outrageously expensive." I don't
think we will ever have one.

it is joke bate by Engineers,

You wouldn't know an engineer if you tripped over one.

and you have no real facts for your "space elevator".

Go educate yourself and get back to us.

[Thomas Koenig]

Post by Sergio

Post by Alain Fournier
Building an elevator, with current technologies, is outrageously
expensive. But if you have one, it can be very useful.

we don't have one, and never will. It is a joke among Engineers.

Well, I did like the space elevator in "Red Mars".

Spoiler:

When it fell, Mars finally acquired a visible equator... it came
down as some sort of continuous meteor.

[reber G=emc^2]

Post by Alain Fournier

Post by Fred J. McCall

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
2017usenet1.subsume.com says...

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
Sure, sure, Star Trek style transporters with infinite range. I'll get
right on that.

No, you won?t. But you apparently *will* use it as a straw man to avoid
actually addressing the likelihood that new technologies developed in
the future will change the economies of space launches. Hell, that?s
essentially what SpaceX is demonstrating today.

Bullshit. SpaceX is not demonstrating any new technologies. They've
combined existing technologies in novel ways to solve the problems
involved in building Merlin engines and Falcon launch vehicles. There
is zero new tech in them. If you believe differently, name a new
technology they're using in their engines, launch vehicles, Dragon, and
etc.

<Sigh> Of *course* there’s no “new technology” in *anything* that’s
in the world today. Your engineering mindset has you in a motivated
reasoning spiral. The fact remains that, over the course of time,
new technologies have been developed that have made their way into
space programs. SpaceX is taking advantage of some of those
technologies today. It is a safe bet that such innovations will occur
in the future, and somebody will take advantage of them.

And it's an even safer bet that none of those 'new technologies' are
going to replace "throwing stuff aft to move forward". A space
elevator on Earth requires not 'new technology', but 'new physics'.

It would be possible to build a space elevator using materials available
today without any major new technology. But that wouldn't be economical.
Not even remotely close to being economical. New materials would be
needed to build a sane space elevator, but new physics isn't needed.
See for instance
http://space.nss.org/media/2000-Space-Elevator-NASA-CP210429.pdf
Alain Fournier

GOP Mafia shuttles killed our space program.Money they stole in 43 years was about 100 billion.They also killed 12 people.Now we pay Russia to get us to the ISS. When I point this out Im called a commie.Get the picture yet Bert Ps think Annenberg,Nixon and Kissenger for what we have today.

[hanson]

"reber G=emc^2" <***@gmail.com> wrote
"I am a proud Jew with a IQ of 1.22" Bert
"I have a Superiority complex" and
"I know how everything works." Bert>>
which is why Glazier bragged:
Bert's cockroach has taught Bert a lot,
and so, Bert became an idiot. Bert
Bert's smart teacher-cockroach-critter
taught Bert how to be a vile Face-Shitter
Bert's Octopus on Bert's Fish-bowl-wall
taught Bert how to be a Graveyard Vandal
------- See: Glazier's Dossier -------
e.g. <http://tinyurl.com/Swine-Glazier-s-REAL-intent>
as <http://tinyurl.com/The-Chosen-Graveyard-Vandal> who
pimps <https://tinyurl.com/Glazier-s-sexual-harassments>

[Jeff Findley]

In article <pfr4bf$hj8$***@dont-email.me>, droleary@
2017usenet1.subsume.com says...

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
2017usenet1.subsume.com says...

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
Sure, sure, Star Trek style transporters with infinite range. I'll get
right on that.

No, you won?t. But you apparently *will* use it as a straw man to avoid
actually addressing the likelihood that new technologies developed in
the future will change the economies of space launches. Hell, that?s
essentially what SpaceX is demonstrating today.

Bullshit. SpaceX is not demonstrating any new technologies. They've
combined existing technologies in novel ways to solve the problems
involved in building Merlin engines and Falcon launch vehicles. There
is zero new tech in them. If you believe differently, name a new
technology they're using in their engines, launch vehicles, Dragon, and
etc.

<Sigh> Of *course* there?s no ?new technology? in *anything* that?s
in the world today. Your engineering mindset has you in a motivated
reasoning spiral. The fact remains that, over the course of time,
new technologies have been developed that have made their way into
space programs. SpaceX is taking advantage of some of those
technologies today. It is a safe bet that such innovations will occur
in the future, and somebody will take advantage of them.

You're the one making the assertion. What new technologies did SpaceX
develop? Be specific.

Jeff

[Fred J. McCall]

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
High altitude balloon launch is a tad risky and only gains you a bit of
altitude and zero velocity. Not worth the complexity and cost, IMHO.

Like I said, it might not *currently* be viable, but as an alternative
technology it brings new sets of trade-offs to the table such that a few
tweaks here and there might make it viable for certain kinds of launches
(e.g., “bulky” items that are hard to make aerodynamically efficient
benefit from starting at the highest possible altitude).

And just what such items do we send to space?

Post by Doc O'Leary

Post by Jeff Findley
BFR/BFS is planned to be "zero waste" from the very beginning. Fully
reusable TSTO with "gas and go" like operations.

But that’s not the true “zero waste” I was talking about. Any resources
that you’re sending up *and* down, along with any fuels you burn to do it
safely, is a waste. It may be a necessary waste for the current launch
technologies, so it’s good to minimize it, but I still say it’s a good
idea to think about ways to shoot stuff into space that doesn’t involve a
lot of heavy stuff coming back to Earth.

Well, let us know if you think of one that doesn't require unobtainium
or payloads to take tens of thousands of gravities on launch.

Post by Doc O'Leary

Post by Jeff Findley
Also don't count out Blue Origin. They're off to a slow start, but have
a very reliable funding source in Jeff Bezos ($1 billion a year).

I’m not counting them out, but when the topic is cost/efficiency, the
basic question is still how much energy is being expended to get each
kg into orbit. So long as the idea is still to send a lot of
supporting (non-fuel) heavy stuff up only to have most of it come back
down, there are wastes that a new technology can come in and improve
upon.

We're constrained by the real world. Magic materials are right out.

Post by Doc O'Leary

Post by Jeff Findley
Besides, how you going to get those space elevator bits into orbit?
That's right, conventional (hopefully reusable) launch vehicles.

Hope for bigger things. I fully believe that, for a society to be
advanced enough to make a space elevator project realistic, it’s value
would be more incremental than revolutionary. Rockets are the best we
have right now, but we’re stuffed if that’s the best we can do.

Just why are we 'stuffed'? Be specific.

[Doc O'Leary]

For your reference, records indicate that

Post by Fred J. McCall

Post by Doc O'Leary
Like I said, it might not *currently* be viable, but as an alternative
technology it brings new sets of trade-offs to the table such that a few
tweaks here and there might make it viable for certain kinds of launches
(e.g., “bulky” items that are hard to make aerodynamically efficient
benefit from starting at the highest possible altitude).

And just what such items do we send to space?

Chicken and egg. The fact is that we *do* sometimes have to
elaborately engineer spacecraft in order to make them small enough to
fit into a nose cone or payload bay of a rocket. A different launch
vehicle/process might allow us more flexibility when it comes to
approaching those very real problems.

Post by Fred J. McCall
We're constrained by the real world. Magic materials are right out.

Straw man. All I’m saying is that it’s foolish to completely discount
new technologies simply because they’re not the rockets you know so
well from the past.

Post by Fred J. McCall

Post by Doc O'Leary
Hope for bigger things. I fully believe that, for a society to be
advanced enough to make a space elevator project realistic, it’s value
would be more incremental than revolutionary. Rockets are the best we
have right now, but we’re stuffed if that’s the best we can do.

Just why are we 'stuffed'? Be specific.

Because rockets have only taken humans as far as the Moon, but we
haven’t gone to the Moon in decades, and we’ll likely see all the
people who *have* been to the Moon dead before we ever return there.
*Maybe* the promise of a Mars colony is achievable with rockets, but
probably not in the lifetime of anyone walking on Earth today. And
even in 1000 lifetimes, rockets aren’t going to take us to explore
another planet around another star.

[Fred J. McCall]

Post by Doc O'Leary
For your reference, records indicate that

Post by Fred J. McCall

Post by Doc O'Leary
Like I said, it might not *currently* be viable, but as an alternative
technology it brings new sets of trade-offs to the table such that a few
tweaks here and there might make it viable for certain kinds of launches
(e.g., ?bulky? items that are hard to make aerodynamically efficient
benefit from starting at the highest possible altitude).

And just what such items do we send to space?

Chicken and egg. The fact is that we *do* sometimes have to
elaborately engineer spacecraft in order to make them small enough to
fit into a nose cone or payload bay of a rocket.

Head and ass. Cite for such payloads? Be specific. You're posting
into a 'sci' newsgroup. Handwavium is not sufficient.

Post by Doc O'Leary
A different launch
vehicle/process might allow us more flexibility when it comes to
approaching those very real problems.

What 'very real problems' would those be?

Post by Doc O'Leary

Post by Fred J. McCall
We're constrained by the real world. Magic materials are right out.

Straw man. All I’m saying is that it’s foolish to completely discount
new technologies simply because they’re not the rockets you know so
well from the past.

Go look up what 'straw man' means. It manifestly does NOT mean
pointing out reality. Cite some of these 'new technologies' and what
it takes for them to work. Be specific. You're crossposting into a
'sci' newsgroup. Handwavium is not sufficient.

Post by Doc O'Leary

Post by Fred J. McCall

Post by Doc O'Leary
Hope for bigger things. I fully believe that, for a society to be
advanced enough to make a space elevator project realistic, it?s value
would be more incremental than revolutionary. Rockets are the best we
have right now, but we?re stuffed if that?s the best we can do.

Just why are we 'stuffed'? Be specific.

Because rockets have only taken humans as far as the Moon, but we
haven’t gone to the Moon in decades, and we’ll likely see all the
people who *have* been to the Moon dead before we ever return there.
*Maybe* the promise of a Mars colony is achievable with rockets, but
probably not in the lifetime of anyone walking on Earth today. And
even in 1000 lifetimes, rockets aren’t going to take us to explore
another planet around another star.

So, not 'stuffed' at all, then. As I thought. What do you propose to
replace rockets with, other than 'magic'?

[Doc O'Leary]

For your reference, records indicate that

Post by Fred J. McCall

Post by Doc O'Leary
Chicken and egg. The fact is that we *do* sometimes have to
elaborately engineer spacecraft in order to make them small enough to
fit into a nose cone or payload bay of a rocket.

Head and ass. Cite for such payloads? Be specific. You're posting
into a 'sci' newsgroup. Handwavium is not sufficient.

Then I must say I note a lack of citations for your own claims. Mine
are easy enough to demonstrate. I can literally link to just about
*any* payload that unfolds to deploy as evidence. Let’s start with
the obvious:

<Loading Image...>

Post by Fred J. McCall

Post by Doc O'Leary
A different launch
vehicle/process might allow us more flexibility when it comes to
approaching those very real problems.

What 'very real problems' would those be?

Asked and answered. Your willful ignorance is not compelling.

Post by Fred J. McCall

Post by Doc O'Leary

Post by Fred J. McCall
We're constrained by the real world. Magic materials are right out.

Straw man. All I’m saying is that it’s foolish to completely discount
new technologies simply because they’re not the rockets you know so
well from the past.

Go look up what 'straw man' means. It manifestly does NOT mean
pointing out reality.

Then you need to look up the definition yourself, because I did not
suggest anything magical. I simply made note of the fact that new
technologies come along all the time. In light of that, it is
foolish to be so dismissive of anything but rockets as launch
vehicles for all stages of space travel.

Post by Fred J. McCall
Cite some of these 'new technologies' and what
it takes for them to work. Be specific. You're crossposting into a
'sci' newsgroup. Handwavium is not sufficient.

It actually is. My argument is not *for* any one technology. It is
simply that rockets have obvious limits, have inherent inefficiencies,
and it’s worthwhile to keep our options open when it comes to thinking
about different ways to get things into orbit and beyond.

Post by Fred J. McCall
What do you propose to
replace rockets with, other than 'magic'?

You continue to build this same straw man. Don’t be a dick. Please
save your threadshitting for Facebook or Twitter.

[Fred J. McCall]

Post by Doc O'Leary
For your reference, records indicate that

Post by Fred J. McCall

Post by Doc O'Leary
Chicken and egg. The fact is that we *do* sometimes have to
elaborately engineer spacecraft in order to make them small enough to
fit into a nose cone or payload bay of a rocket.

Head and ass. Cite for such payloads? Be specific. You're posting
into a 'sci' newsgroup. Handwavium is not sufficient.

Then I must say I note a lack of citations for your own claims.

I haven't made any claims.

Post by Doc O'Leary
Mine
are easy enough to demonstrate. I can literally link to just about
*any* payload that unfolds to deploy as evidence. Let’s start with
<https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#/media/File:JWST_launch_configuration.png>

Not a good example. Things like solar arrays are launched folded
because they can't take acceleration without snapping off, not because
they're 'too bulky'. Try again?

Post by Doc O'Leary

Post by Fred J. McCall

Post by Doc O'Leary
A different launch
vehicle/process might allow us more flexibility when it comes to
approaching those very real problems.

What 'very real problems' would those be?

Asked and answered. Your willful ignorance is not compelling.

I only asked it once and you never answered. Claim fails.

Post by Doc O'Leary

Post by Fred J. McCall

Post by Doc O'Leary

Post by Fred J. McCall
We're constrained by the real world. Magic materials are right out.

Straw man. All I?m saying is that it?s foolish to completely discount
new technologies simply because they?re not the rockets you know so
well from the past.

Go look up what 'straw man' means. It manifestly does NOT mean
pointing out reality.

Then you need to look up the definition yourself, because I did not
suggest anything magical. I simply made note of the fact that new
technologies come along all the time. In light of that, it is
foolish to be so dismissive of anything but rockets as launch
vehicles for all stages of space travel.

It is foolish NOT to be dismissive of airy claims for 'magic'
justified by handwavium. You are in the wrong newsgroup.

Post by Doc O'Leary

Post by Fred J. McCall
Cite some of these 'new technologies' and what
it takes for them to work. Be specific. You're crossposting into a
'sci' newsgroup. Handwavium is not sufficient.

It actually is. My argument is not *for* any one technology. It is
simply that rockets have obvious limits, have inherent inefficiencies,
and it’s worthwhile to keep our options open when it comes to thinking
about different ways to get things into orbit and beyond.

No, it actually isn't. Congratulations on demonstrating that you
don't know shit about either science or engineering.

Post by Doc O'Leary

Post by Fred J. McCall
What do you propose to
replace rockets with, other than 'magic'?

You continue to build this same straw man. Don’t be a dick. Please
save your threadshitting for Facebook or Twitter.

You continue to flap your arms and make chicken noises, insisting you
can fly to the Moon that way. Don't be a dipshit. You are in the
wrong newsgroup.

[Alain Fournier]

Post by Fred J. McCall

Post by Doc O'Leary
For your reference, records indicate that

Post by Fred J. McCall

Post by Doc O'Leary
Chicken and egg. The fact is that we *do* sometimes have to
elaborately engineer spacecraft in order to make them small enough to
fit into a nose cone or payload bay of a rocket.

Head and ass. Cite for such payloads? Be specific. You're posting
into a 'sci' newsgroup. Handwavium is not sufficient.

Then I must say I note a lack of citations for your own claims.

I haven't made any claims.

Post by Doc O'Leary
Mine
are easy enough to demonstrate. I can literally link to just about
*any* payload that unfolds to deploy as evidence. Let’s start with
<https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#/media/File:JWST_launch_configuration.png>

Not a good example. Things like solar arrays are launched folded
because they can't take acceleration without snapping off, not because
they're 'too bulky'. Try again?

The telescope is folded, not only the solar arrays.


Alain Fournier

[Fred J. McCall]

Post by Alain Fournier

Post by Fred J. McCall

Post by Doc O'Leary
For your reference, records indicate that

Post by Fred J. McCall

Post by Doc O'Leary
Chicken and egg. The fact is that we *do* sometimes have to
elaborately engineer spacecraft in order to make them small enough to
fit into a nose cone or payload bay of a rocket.

Head and ass. Cite for such payloads? Be specific. You're posting
into a 'sci' newsgroup. Handwavium is not sufficient.

Then I must say I note a lack of citations for your own claims.

I haven't made any claims.

Post by Doc O'Leary
Mine
are easy enough to demonstrate. I can literally link to just about
*any* payload that unfolds to deploy as evidence. Let’s start with
<https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#/media/File:JWST_launch_configuration.png>

Not a good example. Things like solar arrays are launched folded
because they can't take acceleration without snapping off, not because
they're 'too bulky'. Try again?

The telescope is folded, not only the solar arrays.

And THAT is because you cannot make a single mirror that large to
adequate precision, so once it's in pieces you might as well fold the
sucker up.

[Steve Willner]

Post by Fred J. McCall

The [JWST] telescope is folded, not only the solar arrays.

In particular the 6.5-m primary mirror is folded as well as many
other pieces. It's frightening to watch the deployment videos.

Post by Fred J. McCall
And THAT is because you cannot make a single mirror that large to
adequate precision,

At least three observatories with seven telescopes in active use will
be surprised to learn that. Not to mention additional ones planned.

Every JWST presentation I've seen that mentioned the subject said
that using a deployable (folding) mirror is because the Ariane 5
shroud is too small to fit a 6.5-m mirror. I wouldn't be surprised
if there are "black" programs with the same difficulty.

That said, this particular use case doesn't necessarily justify a
rockoon approach, which will be difficult at best for large boosters.

[Fred J. McCall]

Post by Steve Willner

Post by Fred J. McCall

The [JWST] telescope is folded, not only the solar arrays.

In particular the 6.5-m primary mirror is folded as well as many
other pieces. It's frightening to watch the deployment videos.

Post by Fred J. McCall
And THAT is because you cannot make a single mirror that large to
adequate precision,

At least three observatories with seven telescopes in active use will
be surprised to learn that. Not to mention additional ones planned.

You can do things with earthbound scopes that you cannot do with
something you're going to shoot into space.

Post by Steve Willner
Every JWST presentation I've seen that mentioned the subject said
that using a deployable (folding) mirror is because the Ariane 5
shroud is too small to fit a 6.5-m mirror. I wouldn't be surprised
if there are "black" programs with the same difficulty.

Nope. They use a mirror roughly the size of Hubble's. Remember,
they're looking at something relatively close as such things go.

Post by Steve Willner
That said, this particular use case doesn't necessarily justify a
rockoon approach, which will be difficult at best for large boosters.

Yes. The point is that a balloon does NOT replace a 'first stage'.

[Steve Willner]

Post by Fred J. McCall

Post by Steve Willner
At least three observatories with seven telescopes in active use will
be surprised to learn [that making a 6.5-m primary mirror is impossible]

That should have been five observatories and ten telescopes. I
forgot some. I won't swear I'm not still forgetting others.

Post by Fred J. McCall
You can do things with earthbound scopes that you cannot do with
something you're going to shoot into space.

How does that apply to the current discussion? Launching a 6.5-m
mirror monolithic should in principle be easier than having the same
size mirror deploy to the required precision. The problem is making
it fit into the payload fairing.

Post by Fred J. McCall

Post by Steve Willner
I wouldn't be surprised if there are "black" programs with the
same difficulty.

Nope. They use a mirror roughly the size of Hubble's.

The ones we know about used mirrors that size. Anyone who actually
knows the current situation -- I don't -- wouldn't be allowed to say.

Post by Fred J. McCall
Remember, they're looking at something relatively close as such
things go.

6.5-m mirrors would have advantages over smaller ones. (I don't see
what distance has to do with anything.) I've seen hints that some
have been built and deployed, but that may be salemanship. Companies
vying for the JWST contract would have had an incentive to drop such
hints whether true or not.

Post by Fred J. McCall
The point is that a balloon does NOT replace a 'first stage'.

We agree on that.

[Fred J. McCall]

Post by Steve Willner

Post by Fred J. McCall

Post by Steve Willner
At least three observatories with seven telescopes in active use will
be surprised to learn [that making a 6.5-m primary mirror is impossible]

That should have been five observatories and ten telescopes. I
forgot some. I won't swear I'm not still forgetting others.

And you're still talking about earthbound scopes.

Post by Steve Willner

Post by Fred J. McCall
You can do things with earthbound scopes that you cannot do with
something you're going to shoot into space.

How does that apply to the current discussion? Launching a 6.5-m
mirror monolithic should in principle be easier than having the same
size mirror deploy to the required precision. The problem is making
it fit into the payload fairing.

Oversize fairings are easy.

Post by Steve Willner

Post by Fred J. McCall

Post by Steve Willner
I wouldn't be surprised if there are "black" programs with the
same difficulty.

Nope. They use a mirror roughly the size of Hubble's.

The ones we know about used mirrors that size. Anyone who actually
knows the current situation -- I don't -- wouldn't be allowed to say.

Of course they're allowed to say. You can see the bloody things from
Earth, after all. Past a certain point a bigger mirror doesn't help
you for Earth observation. Atmosphere speckle becomes the driving
parameter and a bigger mirror doesn't help that.

Post by Steve Willner

Post by Fred J. McCall
Remember, they're looking at something relatively close as such
things go.

6.5-m mirrors would have advantages over smaller ones.

No, they wouldn't. The next generation of recce satellites will use a
mirror right around 2.4 meters; the same size used since KH-11.

Post by Steve Willner
(I don't see
what distance has to do with anything.) I've seen hints that some
have been built and deployed, but that may be salemanship. Companies
vying for the JWST contract would have had an incentive to drop such
hints whether true or not.

Don't let them kid you. Distance has a lot to do with everything when
it comes to telescopes.

Post by Steve Willner

Post by Fred J. McCall
The point is that a balloon does NOT replace a 'first stage'.

We agree on that.

[Jeff Findley]

In article <pfkpim$sa0$***@dont-email.me>, droleary@
2017usenet1.subsume.com says...

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
High altitude balloon launch is a tad risky and only gains you a bit of
altitude and zero velocity. Not worth the complexity and cost, IMHO.

Like I said, it might not *currently* be viable, but as an alternative
technology it brings new sets of trade-offs to the table such that a few
tweaks here and there might make it viable for certain kinds of launches
(e.g., ?bulky? items that are hard to make aerodynamically efficient
benefit from starting at the highest possible altitude).

Balloon launch isn't worth the trades which have to be made, IMHO.

Post by Doc O'Leary

Post by Jeff Findley
BFR/BFS is planned to be "zero waste" from the very beginning. Fully
reusable TSTO with "gas and go" like operations.

But that?s not the true ?zero waste? I was talking about. Any resources
that you?re sending up *and* down, along with any fuels you burn to do it
safely, is a waste. It may be a necessary waste for the current launch
technologies, so it?s good to minimize it, but I still say it?s a good
idea to think about ways to shoot stuff into space that doesn?t involve a
lot of heavy stuff coming back to Earth.

By your definition, a passenger carrying aircraft is "waste" because it
flies from one destination to another while carrying passengers. But
that sort of "waste" is absolutely not a metric to optimize. Passengers
are buying the cheapest ticket for the flight that gets them to their
destination. They don't give a rat's ass about the "waste" of the
actual aircraft having to fly there and back.

Back to space launch. We're nowhere near the minimum cost per kg
payload to orbit with chemical launch vehicles. Propellant costs are
currently less than 1% of launch costs, even for SpaceX.

Any "waste" of propellant that allows full reuse of hardware is
currently worth the investment. When your hardware costs more than two
orders of magnitude more than your propellant does, it makes a hell of a
lot of sense to "expend" a bit of propellant to get your expensive
hardware back intact.

When faced with an optimization problem, you look for the biggest "bang
for the buck" bits to optimize. Propellant "waste" is *not* that, not
by a couple orders of magnitude. Also, your launch hardware is a
precious commodity, so it makes all the sense in the world to recover it
and use it multiple times, just like a passenger carrying jet aircraft.

Jeff

[Thomas Koenig]

Post by Jeff Findley
By your definition, a passenger carrying aircraft is "waste" because it
flies from one destination to another while carrying passengers.

Of course.

Firing passengers from large-caliber guns generates much less waste,
obviously, and should be the preferred solution :-)

[Sergio]

Post by Thomas Koenig

Post by Jeff Findley
By your definition, a passenger carrying aircraft is "waste" because it
flies from one destination to another while carrying passengers.

Of course.
Firing passengers from large-caliber guns generates much less waste,
obviously, and should be the preferred solution :-)

perhaps the passengers should walk.

[benj]

Post by Sergio

Post by Thomas Koenig

Post by Jeff Findley
By your definition, a passenger carrying aircraft is "waste" because it
flies from one destination to another while carrying passengers.

Of course.
Firing passengers from large-caliber guns generates much less waste,
obviously, and should be the preferred solution :-)

perhaps the passengers should walk.

Correct me if I'm wrong, Sergio, But then they would be
"pedestrians" rather than passengers, right?

[Sergio]

Post by benj

Post by Sergio

Post by Thomas Koenig

Post by Jeff Findley
By your definition, a passenger carrying aircraft is "waste" because it
flies from one destination to another while carrying passengers.

Of course.
Firing passengers from large-caliber guns generates much less waste,
obviously, and should be the preferred solution :-)

perhaps the passengers should walk.

Correct me if I'm wrong, Sergio, But then they would be
"pedestrians" rather than passengers, right?

you are right, again.
Unless you consider them as "shoe" passengers, ugh.

or if they were bundled together, like a tour group

[Greg Goss]

Post by Thomas Koenig

Post by Jeff Findley
By your definition, a passenger carrying aircraft is "waste" because it
flies from one destination to another while carrying passengers.

Of course.
Firing passengers from large-caliber guns generates much less waste,
obviously, and should be the preferred solution :-)

Bobble tech doesn't bother with the guns. Just encapsulate then blow
a nuke nearby.

[Doc O'Leary]

For your reference, records indicate that

Post by Jeff Findley
Balloon launch isn't worth the trades which have to be made, IMHO.

Certainly not today, no, or people would be doing it. But as I keep
saying, new technologies keep popping up all the time that might make
it viable in the future, at least for a few use cases.

Post by Jeff Findley
By your definition, a passenger carrying aircraft is "waste" because it
flies from one destination to another while carrying passengers.

Yes; that is true by any definition. Just because it’s (arguably) the
least wasteful mode of transportation we currently have says nothing
about how we might travel in the future.

Post by Jeff Findley
They don't give a rat's ass about the "waste" of the
actual aircraft having to fly there and back.

That same logic could have been used regarding ship or train travel
prior to the airplane’s dominance. The point being that they *will*
care as soon as a new technology comes along that allows more
efficient travel. What that might be in reality is unknown, but
clearly something like teleportation or Futurama-style tubes are
sci-fi ways of moving just the bits that need to be moved from one
location to another.

Post by Jeff Findley
When your hardware costs more than two
orders of magnitude more than your propellant does, it makes a hell of a
lot of sense to "expend" a bit of propellant to get your expensive
hardware back intact.

Yes. And I’m just wondering why you can’t just take the next step and
admit that eliminating that expensive hardware *completely* would
represent a cost saving of two orders of magnitude! You wrote it, but
it’s like you weren’t really thinking about what your words actually
meant.

[Fred J. McCall]

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
Balloon launch isn't worth the trades which have to be made, IMHO.

Certainly not today, no, or people would be doing it. But as I keep
saying, new technologies keep popping up all the time that might make
it viable in the future, at least for a few use cases.

Certainly not tomorrow or the next day, either. Just what are these
magical "new technologies" that keep "popping up all the time"?

Post by Doc O'Leary

Post by Jeff Findley
By your definition, a passenger carrying aircraft is "waste" because it
flies from one destination to another while carrying passengers.

Yes; that is true by any definition. Just because it’s (arguably) the
least wasteful mode of transportation we currently have says nothing
about how we might travel in the future.

If you want to talk about "how we might travel in the future", you
need to come up with some suggestions (that aren't PFM).

Post by Doc O'Leary

Post by Jeff Findley
They don't give a rat's ass about the "waste" of the
actual aircraft having to fly there and back.

That same logic could have been used regarding ship or train travel
prior to the airplane’s dominance.

Nope. Ships and trains went 'there and back', too. Logic really
isn't your strong suit, is it?

Post by Doc O'Leary
The point being that they *will*
care as soon as a new technology comes along that allows more
efficient travel. What that might be in reality is unknown, but
clearly something like teleportation or Futurama-style tubes are
sci-fi ways of moving just the bits that need to be moved from one
location to another.

In other words, you're postulating some unspecified 'magic'. You're
posting into the wrong newsgroup. See the 'sci' at the front? That
means SCIENCE. That means you can't just wave your arms and fly to
the Moon. You have to actually put forward the scientific basis for
why you can do so.

Post by Doc O'Leary

Post by Jeff Findley
When your hardware costs more than two
orders of magnitude more than your propellant does, it makes a hell of a
lot of sense to "expend" a bit of propellant to get your expensive
hardware back intact.

Yes. And I’m just wondering why you can’t just take the next step and
admit that eliminating that expensive hardware *completely* would
represent a cost saving of two orders of magnitude! You wrote it, but
it’s like you weren’t really thinking about what your words actually
meant.

Because this is a SCIENCE newsgroup, you twat! Yes, magic would be
nice. We don't have it and never will. Get over it.

[Jeff Findley]

In article <pfmubd$62p$***@dont-email.me>, droleary@
2017usenet1.subsume.com says...

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
Balloon launch isn't worth the trades which have to be made, IMHO.

Certainly not today, no, or people would be doing it. But as I keep
saying, new technologies keep popping up all the time that might make
it viable in the future, at least for a few use cases.

I have an engineering degree. When developing new things, engineers
work with what they have today because they've got schedules and
deadlines to meet. You're talking about technologies not yet invented.
That's research, not development. The two are not the same.

Post by Doc O'Leary

Post by Jeff Findley
By your definition, a passenger carrying aircraft is "waste" because it
flies from one destination to another while carrying passengers.

Yes; that is true by any definition. Just because it?s (arguably) the
least wasteful mode of transportation we currently have says nothing
about how we might travel in the future.

Again, to an engineer the future is what you can do with existing tech.
SpaceX has reduced launch costs beyond what any of the competition can
deliver. They arguably didn't use any new technology at all. DC-X
proved VTVL as a viable take of and landing mode. SpaceX applied that
to Falcon 9's first stage.

Post by Doc O'Leary

Post by Jeff Findley
They don't give a rat's ass about the "waste" of the
actual aircraft having to fly there and back.

That same logic could have been used regarding ship or train travel
prior to the airplane?s dominance. The point being that they *will*
care as soon as a new technology comes along that allows more
efficient travel. What that might be in reality is unknown, but
clearly something like teleportation or Futurama-style tubes are
sci-fi ways of moving just the bits that need to be moved from one
location to another.

Actually moving freight by rail is the cheapest way to move a ton of
goods from point a to point b, assuming you can connect the two by rail.
Aircraft have the advantage of speed, so your Amazon order gets there
overnight instead of in a week or two, but you're paying for Amazon
Prime, which isn't exactly cheap now is it?

Two different sets of requirements lead to two completely different
vehicles. That's how engineering optimization works.

Post by Doc O'Leary

Post by Jeff Findley
When your hardware costs more than two
orders of magnitude more than your propellant does, it makes a hell of a
lot of sense to "expend" a bit of propellant to get your expensive
hardware back intact.

Yes. And I?m just wondering why you can?t just take the next step and
admit that eliminating that expensive hardware *completely* would
represent a cost saving of two orders of magnitude! You wrote it, but
it?s like you weren?t really thinking about what your words actually
meant.

As an engineer I quite simply can't do that. There is no *proven*
existing tech that is cheaper than liquid fueled rocket engines for
reaching orbit.

What you are trying to get me to admit is that eventually, some day,
there may be something better. Sure, there might. Also, monkeys might
fly out of my butt. I'm not waiting for sci-fi to become reality. I'm
working with what I've got today. Again, that's what engineers do.

Jeff

[Sergio]

Post by Jeff Findley
2017usenet1.subsume.com says...

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
Balloon launch isn't worth the trades which have to be made, IMHO.

Certainly not today, no, or people would be doing it. But as I keep
saying, new technologies keep popping up all the time that might make
it viable in the future, at least for a few use cases.

I have an engineering degree. When developing new things, engineers
work with what they have today because they've got schedules and
deadlines to meet. You're talking about technologies not yet invented.
That's research, not development. The two are not the same.

Post by Doc O'Leary

Post by Jeff Findley
By your definition, a passenger carrying aircraft is "waste" because it
flies from one destination to another while carrying passengers.

Yes; that is true by any definition. Just because it?s (arguably) the
least wasteful mode of transportation we currently have says nothing
about how we might travel in the future.

Again, to an engineer the future is what you can do with existing tech.
SpaceX has reduced launch costs beyond what any of the competition can
deliver. They arguably didn't use any new technology at all. DC-X
proved VTVL as a viable take of and landing mode. SpaceX applied that
to Falcon 9's first stage.

Post by Doc O'Leary

Post by Jeff Findley
They don't give a rat's ass about the "waste" of the
actual aircraft having to fly there and back.

That same logic could have been used regarding ship or train travel
prior to the airplane?s dominance. The point being that they *will*
care as soon as a new technology comes along that allows more
efficient travel. What that might be in reality is unknown, but
clearly something like teleportation or Futurama-style tubes are
sci-fi ways of moving just the bits that need to be moved from one
location to another.

Actually moving freight by rail is the cheapest way to move a ton of
goods from point a to point b, assuming you can connect the two by rail.
Aircraft have the advantage of speed, so your Amazon order gets there
overnight instead of in a week or two, but you're paying for Amazon
Prime, which isn't exactly cheap now is it?
Two different sets of requirements lead to two completely different
vehicles. That's how engineering optimization works.

Post by Doc O'Leary

Post by Jeff Findley
When your hardware costs more than two
orders of magnitude more than your propellant does, it makes a hell of a
lot of sense to "expend" a bit of propellant to get your expensive
hardware back intact.

Yes. And I?m just wondering why you can?t just take the next step and
admit that eliminating that expensive hardware *completely* would
represent a cost saving of two orders of magnitude! You wrote it, but
it?s like you weren?t really thinking about what your words actually
meant.

As an engineer I quite simply can't do that. There is no *proven*
existing tech that is cheaper than liquid fueled rocket engines for
reaching orbit.
What you are trying to get me to admit is that eventually, some day,
there may be something better. Sure, there might. Also, monkeys might
fly out of my butt. I'm not waiting for sci-fi to become reality. I'm
working with what I've got today. Again, that's what engineers do.
Jeff

laws of physics do not change, and they constrain possable solutions,
engineers make stuff real, and that stuff complies with physical laws.

[benj]

Post by Sergio

Post by Jeff Findley
2017usenet1.subsume.com says...

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
Balloon launch isn't worth the trades which have to be made, IMHO.

Certainly not today, no, or people would be doing it. But as I keep
saying, new technologies keep popping up all the time that might make
it viable in the future, at least for a few use cases.

I have an engineering degree. When developing new things, engineers
work with what they have today because they've got schedules and
deadlines to meet. You're talking about technologies not yet invented.
That's research, not development. The two are not the same.

Post by Doc O'Leary

Post by Jeff Findley
By your definition, a passenger carrying aircraft is "waste" because it
flies from one destination to another while carrying passengers.

Yes; that is true by any definition. Just because it?s (arguably) the
least wasteful mode of transportation we currently have says nothing
about how we might travel in the future.

Again, to an engineer the future is what you can do with existing tech.
SpaceX has reduced launch costs beyond what any of the competition can
deliver. They arguably didn't use any new technology at all. DC-X
proved VTVL as a viable take of and landing mode. SpaceX applied that
to Falcon 9's first stage.

Post by Doc O'Leary

Post by Jeff Findley
They don't give a rat's ass about the "waste" of the
actual aircraft having to fly there and back.

That same logic could have been used regarding ship or train travel
prior to the airplane?s dominance. The point being that they *will*
care as soon as a new technology comes along that allows more
efficient travel. What that might be in reality is unknown, but
clearly something like teleportation or Futurama-style tubes are
sci-fi ways of moving just the bits that need to be moved from one
location to another.

Actually moving freight by rail is the cheapest way to move a ton of
goods from point a to point b, assuming you can connect the two by rail.
Aircraft have the advantage of speed, so your Amazon order gets there
overnight instead of in a week or two, but you're paying for Amazon
Prime, which isn't exactly cheap now is it?
Two different sets of requirements lead to two completely different
vehicles. That's how engineering optimization works.

Post by Doc O'Leary

Post by Jeff Findley
When your hardware costs more than two
orders of magnitude more than your propellant does, it makes a hell of a
lot of sense to "expend" a bit of propellant to get your expensive
hardware back intact.

Yes. And I?m just wondering why you can?t just take the next step and
admit that eliminating that expensive hardware *completely* would
represent a cost saving of two orders of magnitude! You wrote it, but
it?s like you weren?t really thinking about what your words actually
meant.

As an engineer I quite simply can't do that. There is no *proven*
existing tech that is cheaper than liquid fueled rocket engines for
reaching orbit.
What you are trying to get me to admit is that eventually, some day,
there may be something better. Sure, there might. Also, monkeys might
fly out of my butt. I'm not waiting for sci-fi to become reality. I'm
working with what I've got today. Again, that's what engineers do.
Jeff

laws of physics do not change, and they constrain possable solutions,
engineers make stuff real, and that stuff complies with physical laws.

Actually the laws of physics DO CHANGE as they are only the
understanding of humans and their current interpretation of what they
perceive as reality. What you mean to say is that fundamental
relationships governing physical phenomena do not change even if we
don't quite know what they are.

And what Jeff meant to say is that there is no "publicly known"
technology cheaper than rockets for reaching orbit. Not quite the same
thing as no "proven" technology.

And as for "some day" such things can be important such as trying to
find a workable alternative to fossil fuels which are certain to run
out. The "green" idea of a return to the ox carts and the middle ages
does not seem to be a way to lock in the the current advances of our
civilization, does it?

[Doc O'Leary]

For your reference, records indicate that

Post by Jeff Findley
I have an engineering degree. When developing new things, engineers
work with what they have today because they've got schedules and
deadlines to meet. You're talking about technologies not yet invented.
That's research, not development. The two are not the same.

I never claimed they were. The topic of the thread is *not* “what can
I build today”, it’s “Towards routine, reusable space launch.” That
has nothing to do with today’s technology, and nobody has made the
case that continued use of rockets (even reusable ones) can make it
happen.

Post by Jeff Findley
Two different sets of requirements lead to two completely different
vehicles. That's how engineering optimization works.

Indeed. Which is why I argue that rockets alone are unlikely to be the
only path to space. And they *definitely* are not the path to deep
space.

Post by Jeff Findley
What you are trying to get me to admit is that eventually, some day,
there may be something better. Sure, there might. Also, monkeys might
fly out of my butt.

Really? You think new technologies are butt-monkeys unlikely? Then
let’s get you retired, man, because you are *not* allowing your field
to innovate nearly as much as it needs to.

Post by Jeff Findley
I'm not waiting for sci-fi to become reality. I'm
working with what I've got today. Again, that's what engineers do.

Then you should be looking in engineering newsgroups for that kind of
discussion. Science is about more than just using your current tools.

[Fred J. McCall]

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
I have an engineering degree. When developing new things, engineers
work with what they have today because they've got schedules and
deadlines to meet. You're talking about technologies not yet invented.
That's research, not development. The two are not the same.

I never claimed they were.

Actually you are, but you're too thick to recognize the implications
of your position.

Post by Doc O'Leary
The topic of the thread is *not* “what can
I build today”, it’s “Towards routine, reusable space launch.” That
has nothing to do with today’s technology, and nobody has made the
case that continued use of rockets (even reusable ones) can make it
happen.

You're not going to move "towards routine, reusable space launch" with
technologies that you CANNOT build today and that you cannot even
describe a scientific theoretical basis for. It has EVERYTHING to do
with today's technology and if you think there's something other than
rockets, either trot it out or STFU.

Post by Doc O'Leary

Post by Jeff Findley
Two different sets of requirements lead to two completely different
vehicles. That's how engineering optimization works.

Indeed. Which is why I argue that rockets alone are unlikely to be the
only path to space. And they *definitely* are not the path to deep
space.

Right now there IS no path to 'deep space'. It's sad, but get over
it.

Post by Doc O'Leary

Post by Jeff Findley
What you are trying to get me to admit is that eventually, some day,
there may be something better. Sure, there might. Also, monkeys might
fly out of my butt.

Really? You think new technologies are butt-monkeys unlikely? Then
let’s get you retired, man, because you are *not* allowing your field
to innovate nearly as much as it needs to.

He thinks that your 'magic' technology that breaks the laws of physics
is "butt-monkeys unlikely". I agree with him. So does anyone sane
with any knowledge of science and engineering.

Post by Doc O'Leary

Post by Jeff Findley
I'm not waiting for sci-fi to become reality. I'm
working with what I've got today. Again, that's what engineers do.

Then you should be looking in engineering newsgroups for that kind of
discussion. Science is about more than just using your current tools.

I don't think you know what science is. What it is NOT is airy
speculation about 'new magic' in the sweet by and by.

[Thomas Koenig]

Post by Jeff Findley
2017usenet1.subsume.com says...

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
Balloon launch isn't worth the trades which have to be made, IMHO.

Certainly not today, no, or people would be doing it. But as I keep
saying, new technologies keep popping up all the time that might make
it viable in the future, at least for a few use cases.

I have an engineering degree.

So do I (PhD in chemical engineering).

Post by Jeff Findley
When developing new things, engineers
work with what they have today because they've got schedules and
deadlines to meet.

The world would be a poorer place if that was the case.

Post by Jeff Findley
You're talking about technologies not yet invented.
That's research, not development. The two are not the same.

How would you classify chemical process development? Seems that,
according to your defiinition, I am doing more research than I
thought :-)

[Fred J. McCall]

Post by Thomas Koenig

Post by Jeff Findley
2017usenet1.subsume.com says...

Post by Doc O'Leary
For your reference, records indicate that

Post by Jeff Findley
Balloon launch isn't worth the trades which have to be made, IMHO.

Certainly not today, no, or people would be doing it. But as I keep
saying, new technologies keep popping up all the time that might make
it viable in the future, at least for a few use cases.

I have an engineering degree.

So do I (PhD in chemical engineering).

That's nice. What would be your reaction if I speculated about a
chemical with 'magic' properties that could be used to build a space
tether here on Earth (I say 'magic' because it requires more strength
in tension than is theoretically possible)?

Post by Thomas Koenig

Post by Jeff Findley
When developing new things, engineers
work with what they have today because they've got schedules and
deadlines to meet.

The world would be a poorer place if that was the case.

That IS the case. You're a chemical engineer. When you need to
design a new industrial process to produce some chemical, do you run
off and try to pull something out of your ass or do you start with
known reaction pathways and mechanisms?

Post by Thomas Koenig

Post by Jeff Findley
You're talking about technologies not yet invented.
That's research, not development. The two are not the same.

How would you classify chemical process development? Seems that,
according to your defiinition, I am doing more research than I
thought :-)

You're certainly doing SOME research, but I assume what you're doing
is trying to come up with ways to optimize known reaction pathways so
that the one you want 'wins'. In other words, you're starting with
what you know today rather than postulating some undiscovered chemical
reaction.

[Fred J. McCall]

Post by Doc O'Leary
For your reference, records indicate that

Post by Fred J. McCall

Post by Doc O'Leary
What are the actual numbers when it comes to savings from a reusable
rocket?

That depends on a lot of things.

Well, sure, but it always helps to have some data to work with before
beginning an optimization process. Best/worst cases or averages or
whatever. What the savings is related to the total cost of the launch
is going to be guiding factor on how much effort it makes sense to
expend to re-use different parts of the system.

When I say it depends on a lot of things, I meant exactly that. You
can't 'invent' data. Space Shuttle was supposedly 'partly reusable',
but it was MORE expensive than throwing away hardware with similar
capabilities. SpaceX seems to think that they can reduce the cost of
a launch by a third by reusing first stages (and that was before they
were optimized for reuse). They think that BFR/BFR Spaceship will
cost less than 1% of the hardware price per flight (a fully reusable
system good for 100 launches before servicing). Pick your poison.

Post by Doc O'Leary

Post by Fred J. McCall

Post by Doc O'Leary
It?d also be interesting to know how new technologies might
impact the economics of launching items into space (including just making
disposable launch vehicles much cheaper).

Real reuse will always be cheaper. If you can make disposable launch
vehicles much cheaper, the same technologies allow making reusable
launch vehicles much cheaper.

That is non-obvious. Ideally, I would think a “zero waste” system
would be cheapest; every kg of mass that gets sent up either stays up
(doing something useful) or was the fuel. All this booster landing
(and subsequent refurbishing for relaunch) we’re seeing, while cool,
is definitely *not* the most efficient use of resources.

Yes, magic would be more efficient, but we don't have magic.

Post by Doc O'Leary

Post by Fred J. McCall

Post by Doc O'Leary
Once you start to contemplate
the need for multiple daily launches, even recovering boosters to reuse
them seems like a slow and labor-intensive process.

But orders of magnitude faster than throwing them away and building a
new one.

But that’s still assuming old technologies rather than new ones. You
don’t “throw away” a space elevator.

You also can't build one without 'magic' because it is impossible for
materials to be strong enough.

Post by Doc O'Leary
Nor a mag-lev cannon.

Now the payload needs to be 'magic' to withstand the launch.

Post by Doc O'Leary
I’m not
sure how viable a high-altitude balloon launch would be, but it may
also be cheaper than traditional first-stage rockets.

I'm sure. It doesn't accomplish what a first stage accomplishes, so
it doesn't really matter if it's cheaper or not. What it's not is
'effective'.

Post by Doc O'Leary

Post by Fred J. McCall

Post by Doc O'Leary
On the path to a
space elevator, it seems like there should be many more ways to reach
escape velocity that do a better job than what Musk is doing today.

You've discovered a good supply of unobtainium, have you? Otherwise,
rockets are your man for getting stuff to orbit for the foreseeable
future.

It’s always a good idea to noodle around with other technologies, no
matter how impossible they appear to be today.

Building a tether on Earth requires materials that are stronger than
materials can theoretically be. Noodle all you like. Basic laws of
physics aren't going to change no matter how hard you wish.

Post by Doc O'Leary
Because, yes, rockets
are the way to get to orbit, but I’m most interested in the
*unforeseeable* future that has humans on other planets around other
stars. Just being satisfied with rockets is not going to make that
happen.

When you're in entirely the wrong newsgroup. You need something that
starts with 'alt' or 'rec'.

[Jeff Findley]

Post by Fred J. McCall

Post by Doc O'Leary
Because, yes, rockets
are the way to get to orbit, but I?m most interested in the
*unforeseeable* future that has humans on other planets around other
stars. Just being satisfied with rockets is not going to make that
happen.

When you're in entirely the wrong newsgroup. You need something that
starts with 'alt' or 'rec'.

Unfortunately, rec.arts.sf.science is in the stupid distribution list of
the posts in this thread. I've removed it from this reply.

Jeff

[Fred J. McCall]

Post by Jeff Findley

Post by Fred J. McCall

Post by Doc O'Leary
Because, yes, rockets
are the way to get to orbit, but I?m most interested in the
*unforeseeable* future that has humans on other planets around other
stars. Just being satisfied with rockets is not going to make that
happen.

When you're in entirely the wrong newsgroup. You need something that
starts with 'alt' or 'rec'.

Unfortunately, rec.arts.sf.science is in the stupid distribution list of
the posts in this thread. I've removed it from this reply.

I know where the git is posting from. I'm trying to make the point
that he shouldn't be posting HERE.

[Greg Goss]

Post by Doc O'Leary
For your reference, records indicate that

Post by Robert Clark
Several companies are proposing satellite megaconstellations that would
require hundreds to thousands of communications satellites. This may finally
provide the impetus to produce reusable launchers.

What are the actual numbers when it comes to savings from a reusable
rocket? It’d also be interesting to know how new technologies might
impact the economics of launching items into space (including just making
disposable launch vehicles much cheaper). Once you start to contemplate
the need for multiple daily launches, even recovering boosters to reuse
them seems like a slow and labor-intensive process. On the path to a
space elevator, it seems like there should be many more ways to reach
escape velocity that do a better job than what Musk is doing today.

"Recovering" them? In Musk's version, they land themselves near the
re-assembly plant.

[Jeff Findley]

Post by Greg Goss

Post by Doc O'Leary
For your reference, records indicate that

Post by Robert Clark
Several companies are proposing satellite megaconstellations that would
require hundreds to thousands of communications satellites. This may finally
provide the impetus to produce reusable launchers.

What are the actual numbers when it comes to savings from a reusable
rocket? It?d also be interesting to know how new technologies might
impact the economics of launching items into space (including just making
disposable launch vehicles much cheaper). Once you start to contemplate
the need for multiple daily launches, even recovering boosters to reuse
them seems like a slow and labor-intensive process. On the path to a
space elevator, it seems like there should be many more ways to reach
escape velocity that do a better job than what Musk is doing today.

"Recovering" them? In Musk's version, they land themselves near the
re-assembly plant.

News this week of SpaceX proposing new KSC facilities for Block 5
boosters. My guess is they won't be shipping them back to California
until they're ready for refurbishment. If they ever get to that point.

Jeff

[Robert Clark]

In that discussion I forgot the key point. The most important factor in
regards to cost is not the development cost.
The key cost factor is what they would charge per flight for a reusable
launcher. Robert Zubrin made this point insightfully in one of his books. He
recounts that he made the argument for reusable launchers in his former job
with one of the big launch companies.

He argued that they could cut the cost of launch by an order of magnitude.
The company execs responded: why would we do that? Their view was their
revenue would then be slashed by a factor of ten. They were assuming the
market would still be the same but they would be getting one-tenth the
revenue.

So the OldSpace companies were acting quite rationally in a business sense
in discounting reusability. They were saying the market was not enough to
make it advantageous to them.

But if there were a large market then they would make more money making more
launchers at the lower price. That is, the price would be reduced by a
factor of ten but the number of launches would be increased by more than a
factor of ten.

Also, the importance of the large market and lowered prices for satellite
launches extends beyond that of just the satellite market. By making
launches at such reduced prices, that increases the possible market for
passenger flights to space. So the impending megaconstellation launches may
also bring to fruition the long desired routine passenger flights to space.

Bob Clark


------------------------------------------------------------------
Single-stage-to-orbit was already shown possible 50 years ago
with the Titan II first stage.
In fact, contrary to popular belief SSTO's are actually easy.
Just use the most efficient engines and stages at the same time,
and the result will automatically be SSTO.
Blog: Http://Exoscientist.blogspot.com
------------------------------------------------------------------

[n***@gmail.com]

Do you know what rocket smoke it? I really do not know exactly what the effenicy of a rocket engine it since everyone is concealing the number but I would guess by .01 % or less. Shit that is so lame it makes me want to take a shit. What about you. Do rockets engines make you get an erection of something?