Towards routine, reusable space launch.

JF Mezei wrote on Wed, 13 Jun 2018
16:28:16 -0400:

On 2018-06-13 06:46, Jeff Findley wrote:
In article ,

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.


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.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn

On Jun/13/2018 at 5:35 PM, Fred J. McCall wrote :
Doc O'Leary wrote on Wed, 13 Jun
2018 12:57:19 -0000 (UTC):

For your reference, records indicate that
Jeff Findley wrote:

In article , droleary@
2017usenet1.subsume.com says...

For your reference, records indicate that
Jeff Findley wrote:

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.

Bull****. 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-Spac...A-CP210429.pdf


Alain Fournier

JF Mezei wrote on Wed, 13 Jun 2018
17:55:45 -0400:

On 2018-06-13 17:35, Fred J. McCall wrote:

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'.


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.


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.


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)


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

https://en.wikipedia.org/wiki/Projec...ear_propulsion)


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.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw

Alain Fournier wrote on Wed, 13 Jun 2018
19:39:10 -0400:

On Jun/13/2018 at 5:35 PM, Fred J. McCall wrote :
Doc O'Leary wrote on Wed, 13 Jun
2018 12:57:19 -0000 (UTC):

For your reference, records indicate that
Jeff Findley wrote:

In article , droleary@
2017usenet1.subsume.com says...

For your reference, records indicate that
Jeff Findley wrote:

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.

Bull****. 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-Spac...A-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).


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw

On Thursday, June 14, 2018 at 6:53:56 AM UTC+2, Fred J. McCall wrote:

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

According to Wikipedia the best tensile strength measured to date for multi-walled carbon nanotubes in 63GP, well short of a highly theoretical 300 GP.. No one talking (writing) about this number seems to think that 300 GP will exceed atomic forces).

If I recall the last time the 'Great Space Elevator' debate stomped across the Usenet, the maximum measured tensile strength of MWCN (in laboratories) was doubling every few months. Even if that has slowed to a couple of years that means the goal set in the aforementioned PDF (i.e. that the Space Elevator is a technical challenge for the latter half of the 21st century) is at least theoretically achievable.

The same PDF does also claim that a Space Elevator is theoretically possible with much weaker material (a super variant of one of the Spectra or Kevlar materials - I think) but that the sheer size of the needed cable taper makes it UNECONOMICAL, even as a multi-nation supported vanity program.

If the meantime any advance in material science (i.e. the availability of much stronger composites made possible by bulk MWCN) will make traditional TSTO even more attractive. It might even make SSTO practical.


Take care.

Regards
Frank Scrooby

In article , droleary@
2017usenet1.subsume.com says...

For your reference, records indicate that
Jeff Findley wrote:

In article , droleary@
2017usenet1.subsume.com says...

For your reference, records indicate that
Jeff Findley wrote:

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.

Bull****. 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
--
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.

In article ,
says...

On 2018-06-13 06:46, Jeff Findley wrote:
In article ,

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/educatio...mmes/astro-pi/

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

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

Innovation in terms of engineering, but not new technology.

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-...rced-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
--
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.

On 14-6-2018 6:53, Fred J. McCall wrote:
Alain Fournier wrote on Wed, 13 Jun 2018
19:39:10 -0400:

On Jun/13/2018 at 5:35 PM, Fred J. McCall wrote :
Doc O'Leary wrote on Wed, 13 Jun
2018 12:57:19 -0000 (UTC):

For your reference, records indicate that
Jeff Findley wrote:

In article , droleary@
2017usenet1.subsume.com says...

For your reference, records indicate that
Jeff Findley wrote:

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.

Bull****. 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-Spac...A-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).


There was a design for interstellar traffic, using a big protection plate
behind the spacepod, using a spring loaded tube to connect them,and
provide a bit of distance between ship and plate.
Explode nuclear bombs behind that shield.
Current technology could implement it, but it would be kind of expensive.

Sjouke Burry wrote on Thu, 14 Jun
2018 15:15:59 +0200:


There was a design for interstellar traffic, using a big protection plate
behind the spacepod, using a spring loaded tube to connect them,and
provide a bit of distance between ship and plate.
Explode nuclear bombs behind that shield.
Current technology could implement it, but it would be kind of expensive.


Notional design, not a real design. 1950's technology could implement
it, as that was when the idea was originally looked at (Project
Orion). This is not 'interstellar traffic' in the sense 'Doc' means,
since transit times would be measured in centuries.

For your reference, records indicate that
JF Mezei wrote:

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 ?

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

--
"Also . . . I can kill you with my brain."
River Tam, Trash, Firefly