Back to the Future? The Command Module Flies Again?

On Tue, 27 Jan 2004 13:07:31 +1100, in a place far, far away, Stephen
Souter made the phosphor on my monitor
glow in such a way as to indicate that:

In article ,
Brett O'Callaghan wrote:

(Rusty B) wrote:

Boeing is using Command Module shaped hardware
and an Apollo type escape rocket in some of its recent concept drawings:

I guess a good design is a good design, regardless of how old or
recycled it is. ;-)

If Boeing is contemplating recycling the CM, can a recycled Saturn V be
far behind?

Yes. The capsule will be a new design. If a heavy lifter is built,
it will be as well.

"Pat Flannery" wrote in message
...

Has anyone thought of having an inner and outer layer of fabric,
and pumping something like self-hardening polyurethane foam in
between them to inflate the form? Not only would this lead to a
very structurally strong design, but the solidified foam should be
able to soak up micrometeor impacts, and an accidental piercing
of the inner wall by the astronauts wouldn't be much of a
problem, as it would only expose the solid foam. Such a
structure would have superb insulation properties, and
additionally, radiation absorbing materials could be mixed into
the foam for solar storm protection on Moon and Mars
missions.... and the solidified unit could be depressurized if
desired without losing its form and going slack. Then there is the
fact that new equipment could be attached by simply anchoring it
into the solidified foam.

Pat


Looking at the Transhab design, I am still trying to work out why they
used foam at all, I can not see that it does anything useful, accept
making packing and deploying difficult. It is in a vacuum, foam does
not improve your thermal insulation, it hurts it. Nextel is better than
foam as an impact barrier and in space, space is cheap, so why use foam
as a separating layer?

The type of construction that would seem preferable to me is many well
spaced layers of Nextel, (or equivalent), constructed much like a tent,
with two flexible circumferential hoop sticks at each end to maintain
the shape. Within this thermal insulating and impact absorbing shell
one might inflate a two or three shell pressure vessel, with each shell
able to take the full pressure if necessary. This would provide
redundancy, (which Transhab does not have), against internal and
external puncture, potentially, slow leaks could be isolated, found, and
repaired. Water could also be pumped into the gap between two such
shells if desired for radiation shielding. Perhaps I would further
favour a well separated internal fabric layer, purely for internal
protection, perhaps porous and incorporating the ventilation system.

I do not know what the weight of the Transhab shell was, but I think for
a similar size the above should be possible for less than 2000kg, much
less if you push it. The outer protective tent might be around 10% of
this by weight. Such an open ended outer tent might also be useful as a
protective hanger.

Pete.

"Dr. O" dr.o@xxxxx wrote in message .. .
"Brett O'Callaghan" wrote in message
...
(Rusty B) wrote:

Boeing is using Command Module shaped hardware
and an Apollo type escape rocket in some of its recent concept drawings:

I guess a good design is a good design, regardless of how old or
recycled it is. ;-)

Absolutely. The Russians have been using them for years

I had hoped that, in keeping with the desire for a simpler
entry/descent/landing than the (99% successful) Space Shuttle option,
we might have opted for a self-orienting reentry vehicle for the CEV.
I am thinking of off-nominal cases when even your entry-attitude
rockets might not be working.

Mercury and Gemini were self-orienting (Carpenter mentioned Faget's
confidence of less than a 60-degree oscillation of the nose during
reentry, but I guess it was blunt-end forward, or BEF, on average!),
and Soyuz is, too. But the Apollo command module shape had two stable
entry attitudes, BEF and nose-forward. The launch escape tower
included canards to destablize the nose-forward attitude so the CM
would end up BEF for parachute deployment (IIRC).

So my question is: what is a good shape (besides sperical, like Vostok
and Voskhod) that is self-orienting for re-entry?

John Charles
Houston, Texas

John Charles wrote:

I had hoped that, in keeping with the desire for a simpler
entry/descent/landing than the (99% successful) Space Shuttle option,
we might have opted for a self-orienting reentry vehicle for the CEV.
I am thinking of off-nominal cases when even your entry-attitude
rockets might not be working.

Mercury and Gemini were self-orienting (Carpenter mentioned Faget's
confidence of less than a 60-degree oscillation of the nose during
reentry, but I guess it was blunt-end forward, or BEF, on average!),
and Soyuz is, too. But the Apollo command module shape had two stable
entry attitudes, BEF and nose-forward. The launch escape tower
included canards to destablize the nose-forward attitude so the CM
would end up BEF for parachute deployment (IIRC).

Mercury had a small spoiler flap attached to its nose to orient it
blunt-end forward during re-entry. I think it was designed to put
the capsule in that attitude during an abort as well.

--Bill Thompson

On 27 Jan 2004 00:03:25 GMT, "Jorge R. Frank"
wrote:

Cardman wrote in
:

They usually are, where Boeing's diagrams do not indicate thick walls.

Don't take those "diagrams" seriously. They're concept art, nothing more.

That was already my view, but they can only provide assumptions about
such technology.

Then why bother with inflation if the walls are so thick? As in that
case you could just use solid metal or some plastics.

Because it's possible to pack a much larger volume into a given launch
vehicle shroud.

I see.

The walls are actually composed of a Kevlar inner bladder
surrounded by alternating layers of open-cell foam and Nextel fabric.

It was good to see partitioned foam in order to minimise thermal loss.

So what about windows on these things? As if you are going to build
large structure out of them, then they will be desiring windows.

The foam can be packed tight for launch, then inflated along with the
rest of the volume. See:

http://www0.arch.cuhk.edu.hk/~hall/s...-2002-6105.pdf

Yes I see what these are about now.

So how these things do in terms of mass?

In terms of mass per unit volume, pretty good.

Then the big question must be on the feasibility of using TransHab
modules on NASA's future Moon Base? As I can only see that doing so
would greatly reduce costs.

Cardman
http://www.cardman.com
http://www.cardman.co.uk

In article ,
John Charles wrote:
...But the Apollo command module shape had two stable
entry attitudes, BEF and nose-forward. The launch escape tower
included canards to destablize the nose-forward attitude so the CM
would end up BEF for parachute deployment (IIRC).

It was a little more complicated than that. The canards were to ensure
base-first orientation during the atmospheric aborts. For an actual
reentry, from a high-altitude abort, even they weren't good enough:
interaction of the tower shock with the CM produced a weak nose-forward
stable position that bigger canards didn't fix.

But since stability there was weak, the CM couldn't settle into that
position if it was rotating at more than about 2deg/s. So high-altitude
abort procedures called for immediately establishing a 5deg/sec pitch
rate, ensuring that it would always stabilize base-first.

While it is nice to have dependable passive stability on reentry, you do
pay a price for it, and the tradeoff needs careful assessment. There is
nothing inherently risky about needing active attitude control early in
reentry; in many cases you need active attitude control to get to that
point anyway. Providing redundant guidance and RCS may be easier,
especially given that you probably want those anyway...

To quote a comment from a 1990 Aerospace Safety Advisory Panel memo:

...for every failure mode someone can envision, someone else must
provide a solution... The proven costs of such solutions are money,
schedule delays, and additional unknowns. I believe that many of
our solutions to problems create more serious problems through added
complication, dilution of effort, and increased time compression on
already over-stressed work loads... Unless management and program
personnel develop a sense of proportion, we will forever be trying
to chase things to the last decimal point, frittering away limited
resources on insignificant issues.

The author of that, by the way, was an astronaut.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

Cardman wrote in
:

So what about windows on these things? As if you are going to build
large structure out of them, then they will be desiring windows.

I confess I haven't dug into the issue of windows. Should be possible, but
could be a challenge.

Then the big question must be on the feasibility of using TransHab
modules on NASA's future Moon Base? As I can only see that doing so
would greatly reduce costs.

I agree they have the potential. I think it would be smart to test one in
LEO first, to see if they can really fulfill that potential.


--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

On Mon, 26 Jan 2004 21:09:49 +0100, "Dr. O" dr.o@xxxxx wrote:


"Cardman" wrote in message
.. .
On 25 Jan 2004 23:26:36 -0800, (Rusty B)
wrote:

Boeing is using Command Module shaped hardware
and an Apollo type escape rocket in some of its recent concept drawings:

Boeing is just trying to cover all options since NASA has not yet
clearly defined their CEV needs, even if we all have a good idea what
they will require. Think "moon".

Got the Delta IV-H in there I see, as well as a Mars craft, a Luna
space station, cargo modules, TLI hardware and a Luna Lander.

The moon stuff looks pretty viable to me.

Maybe so, but I do not think that going with a Luna Space Station and
separate CEV and Luna Lander is the way to go.

The Mars craft is just rubbish, unless it's for a flyby (very possible,
but extremely dangerous because of solar flares).

It did look on the small side to me.

Well, you know what Boeing's concept drawings are like, when they no
doubt had them around for years and just play "mix and match" whenever
they suit NASA's latest ideas.

So what they come up with in the end would be very different to those.

I see that Boeing's designs have changed a great deal in the past
year, when beforehand they also presented wing designs, while now they
show only capsules.

I predicted some time ago (on the basis of some NASA statement which someone
posted in this NG) that they would go for a capsule and scrap all winged
spacecraft.

Well I came to this group about a year ago and clearly pointed out why
NASA should use a capsule instead of a wing craft.

Some time following they came to that same conclusion, which is why
winged concepts were dropped. After all there was a big debate going
on at the time if wings or capsules were better.

NASA even later on considered increasing their number of crew members
on such craft due to the mass savings from not having wings. Not sure
if they ever followed through with that idea though.

I hereby also predict that the Shuttle will be scrapped BEFORE
the 2010 deadline, perhaps as early as 2007.

Hey that is my idea. :-]

The only problem is that NASA has to find the extra funding in order
to increase their Shuttle launch rate. Still, the completion of the
ISS early, would allow early scrapping of the Shuttle and it's support
systems, which would make the CEV come on-line about 3 years earlier.

Then lets not forget that a complete ISS three years early, would
allow full station occupation and a good research return.

I suppose that they can always beg congress for this money, where they
could even pay back this loan in about 2008/9 by delaying the CEV by
about a year.

Better yet congress could spread out any such loan repayment in the
longer term by tapping NASA's budget between 2008 and 2012, when that
should not harm CEV construction much.

Since it makes sense to me, then they should go do it, if they can get
the funding and desire their CEV early. Not to forget landing on the
Moon BEFORE 2015, by about 2013 by my estimate.

Any person who does not want that to happen must have a job working on
the Shuttle, when it is all good news.

Anyone wishing to donate a few billion to NASA's Shuttle flight rate
is welcome to make offers. How much would about 12 to 15 flights a
year cost in total by the way?

Cardman
http://www.cardman.com
http://www.cardman.co.uk

(Rusty B) wrote in message . com...
Boeing is using Command Module shaped hardware
and an Apollo type escape rocket in some of its recent concept drawings:

According to NASA Watch:

"Boeing has placed a dozen or so graphics online depicting a varety
of spacecraft one would expect to see proposed as part of the
President's new space policy."

http://www.nasawatch.com/

http://boeingmedia.com/images/search...roduct_id=1525

Some earlier Boeing OSP CM capsule shaped concepts.

http://boeingmedia.com/images/search.cfm?product_id=986


These concepts would appear to require five or six
enhanced Delta IV-H launches for each lunar mission -
one launch for the CEV, two for the upper stages
stacked behind the CEV, one for the lunar lander,
and one or two for the upper stages to boost the
lunar lander.

A few years ago, a Delta IV-H launch was expected
to cost $150 million. Assuming costs have risen
25% (in line with Atlas V cost increases), the
launch costs alone for each lunar landing mission of
this type could be expected to total $0.9 to
$1.2 billion. The spacecraft and other mission costs
would surely equal or exceed that amount, resulting
in a total per-flight mission cost in the $2-3 billion
range. If this cost must come out of the existing
$6-ish billion shuttle/ISS budget, one would expect
NASA to be able to perform no more than a couple of
lunar missions per year.

This would cut NASA's annual astronaut seats to only
eight from the current 35-40, unless NASA also
continues to perform a few LEO missions in support
of something like ISS.

- Ed Kyle

On Mon, 26 Jan 2004 20:20:58 GMT, (Henry Spencer)
wrote:

As others have noted, with multi-wall design, this isn't an issue. In
fact, inflatables generally score better on debris/meteorite puncture
resistance, because the designers of rigid modules have trouble providing
adequate spacing between the bumper sheet and the backstop. Wider
spacing, to let the debris cloud spread out farther before it hits the
backstop, improves protection *much* more than adding mass... but since
the bad experience on Skylab, NASA has been afraid of *deployable*
bumpers, so added wall depth has to come out of interior space, which
discourages wide spacing. But inflatables deploy everything anyway, so
they can have quite wide spacings between the layers of their walls.

What are the odds of having your moon base using these?

Interestingly enough they have not yet considered making a larger
rocket better suitable for Moon launches, like with using those RS-84
engines that they are currently developing.

The immediate money is going to be for spacecraft, not rockets, and the
ability to fly on the existing EELVs is certain to be a requirement.

That sounds to me like NASA cutting their own legs off before they
learn to walk claiming "we don't need legs when we can crawl".

The earlier that they face that fact that one day they will be needing
to move a large volume of mass in the general direction of the moon,
then the earlier that they will plan on adding a new rocket into their
master plan.

Not today, not tomorrow, but one day between 2015 and 2020 it will
move from an option into a requirement.

So this is not a good time to be pushing new rockets.

I believe that it is, when doing the Moon on the Delta IV-H is just a
bad idea.

I have no problems with using the Delta IV-H for taking their CEV into
LEO or even GEO (even if others do, due to the no engine out option),
but they should realise that if their Moon plans are to work out in
any realistic way, then they would either need a new bigger rocket, or
a whole LEO assembly space station.

Since I doubt that they would be allowed another space station, then
doing Lunar orbital work seems like the better option anyway.

Now, if they wish to build their CEV first then fine, but at some
point shortly following they will be needing their new rocket. I hope
that they take this into account, instead of stunting their whole
future by building their moon plans around baby rocket IV-H.

(They have surely
*considered* it, but have decided to put the idea on the shelf for a
while -- it's not what NASA wants to hear just now.)

I would be under the assumption that they had some kind of "master
plan", which defines how everything should go together.

That master plan from what I can see should go CEV, CEV's cargo
module, the big cargo module, new rocket, moon base.

It would be particularly amusing if the rocket in question was an EELV or
EELV derivative, since both of those use major foreign components, the
"sad losers" being able to do some things better than the Americans can.

Certain Russian rocket engines come to mind, where even the Chinese
should soon impress you with their space plans advancing in leaps and
bounds.

Most notably, Atlas V uses Russian engines because no competitive US
engine was available.

I remember seeing a programme a few years ago, shortly following when
the Russians and Americans started working together, where the
Americans had a good look at the Russian hardware.

One of the first things they noticed was the impressive performance
figures for the modern Russian rocket engine, when their pre-burner
based design put all comparative US versions to shame.

Sure enough the Russians showed then how they came to build these
engines, where there was their room with like one hundred rocket
engines on the floor.

What they had of course been doing was to build a rocket engine, test
it, and then to figure out how to make it better. And so they built a
new engine in this design, tested it, improved it and so on, until
they had their room full of a hundred engines.

So that is how that rocket engine came about, where quite simply it
would be quite difficult for US companies to do better.

LM of course knew that those are good engines, where it will cost them
more to make their own copy, not to forget upsetting the Russians.

The last thing I recall was how the Americans said that they would
have to learn to build their new engines like that. Not yet it seems.

(In fact, if one wanted to revive the Saturn V itself right now and didn't
have an unlimited budget, one would seriously consider Russian engines for
the first stage,

True, where in a way that could almost happen.

What I mean is that Boeing's LP-1 based RS-84 engines is borrowing
this pre-burner idea (and maybe more) from this Russian design, where
the higher chamber pressure should produce great performance results.

Put five of those engines on your new moon rocket, then you would
certainly be able to shift some serious mass.

and the obvious choice for the second and third stages is
the French Vulcain, which is available off the shelf and has specs broadly
similar to the old J-2 except better.)

Yes, but don't forget that using the RS-84 instead of those direct
Russian engines in the first stage makes for a reusable instead of a
disposable first stage.

They could even stick on some simple parachutes to have it land
safely, even if in the ocean is not the best idea.

As the one thing that I do know is that making your Saturn V-b is not
the best design idea due to the high cost that helped to end this
project in the first place.

Cardman
http://www.cardman.com
http://www.cardman.co.uk