A Apollo reconsat?

David Spain wrote:

Comrade Patsky!

Note imperialist attempt to copy Soyuz re-entry design an American spy
must have stolen from Soviet design bureau! (2nd image, far left
retry body, so to speak)...

Now here is a fun read: http://www.astronautix.com/articles/wastolen.htm
Did the Soviets rip off the GE Apollo design for their Soyuz?

Pat

;-)

David Spain wrote:

Yep. Back to cryogenics in the ascent stage. Why the driving need for
high ISP in the ascent stage?

To simplify the overall spacecraft by using the same fuels in both the
descent and ascent stages.

They intending on bringing back weighty
cargo, i.e. lots and lots of samples I presume? Doesn't this choice also
limit the amount of time that can be spent on the surface?

I'm wondering about that myself... although the Apollo SM carried LOX
and LH2 to power its fuel cells (as does the Shuttle), you would think
there would be a boil-off problem for the length of the Moon missions
being contemplated; on the other hand, it does mean the Altair can use
its propellants to generate both electrical power and drinking water via
its fuel cells.
So I imagine they will power the fuel cells via the natural boil-off
from the cryogenic tankage once they have landed.
The RL10 is a very good choice for its engines, as it is already fully
developed and highly efficient and reliable.


To re-use ascent stage for TEI would require a trans-stage, with EVA
to attach fuel lines. Size of tankage for LO2/LH2 probably precludes
this approach tho.

Yeah, in this case I think they are just going to count on everything
working right, like on Apollo.


Although LOX/LH2 will give Altair a very good specific impulse, it
will also make it pretty large, due to the low mass-versus-volume of
the LH2.

I'm all for simplicity in the ascent stage engine, hypergolics give you
that too though, and compatibility with SM and a longer shelf life, but
less cargo up-lift. Pity, it might require more flights to get the same
amount of samples back.... ;-)

Since you are going to be spending a couple of weeks up there, you might
be able to examine a lot of the samples right on the Moon and only bring
back any really interesting things you found.
One question here though is a mission that spends over two weeks on the
surface...are they intending to make EVAs in the lunar night? That would
make designing the EVA suits difficult, as during the lunar day you are
trying to get rid of your body heat while at the same time not letting
the suit overheat in the bright sunlight, whereas at night the problem
will probably be trying to keep warm in the cold lunar darkness...trying
to get one spacesuit design that can do both of those things well could
be tricky.


One thing is notable about this project...for as many years as we are
into the Constellation program, we still haven't gotten even a
semi-finalized idea of exactly what Altair will look or be like yet.

Not surprising given the history of Apollo either. LM was the most
'out-there' in terms of design. Didn't I read here not long ago that
it wasn't ready until quite late? Didn't some Apollo hardware CM/SM
fly even *before* the LM design was finished?


Yeah, the LM wasn't completly ready to go till the beginning of 1969,
which is one reason that Apollo 8 went around the Moon without one on
its Saturn V, rather than checking out a LM in Earth orbit, like Apollo
9 did.
You want to read up on a lot of problems, check out the chronology of
the LM: http://www.astronautix.com/craft/apollolm.htm
Nothing seemed to be working right during its development.
The episode devoted to the LM on the "From The Earth To The Moon"
miniseries ("Spider") is really amusing as the engineers at Grumman are
slowly driven half-mad by building it, a thing they thought was going to
be fairly easy when they were awarded the contract for it.
I was somewhat surprised that Bell didn't get the contract for it, as
when you think about it, it's fairly similar to a helicopter in a lot of
ways...Bell did build the jet-powered flying trainer for it, and managed
to almost kill several people with those, including Neal Armstrong:
http://www.astronautix.com/craft/apoollrv.htm


That would almost be a necessity; IIRC there were plans for a
possible Apollo farside mission or before the program got terminated,
and I think they were going to use some sort of lunar orbiting
comsats for that one.

Let's split this one off into a separate thread. I'd like to get the
'collective' thoughts on the best approach to this one.

Yeah, that would be interesting to speculate on.


Pat

"Pat Flannery" wrote in message
dakotatelephone...


Greg D. Moore (Strider) wrote:


Fair enough. One of the scenarios I was specifically thinking of was a
tumbling, uncontrolled Orion.

We both thought of that little scenario right off of the bat, didn't we?
I think the clue to getting out of this situation via EVA involves
watching "2010" several times and heading toward the midpoint of the spin.
:-)

Pat

It's one of the few that really turns the problem into a major problem
quickly.

Dead Orion, dock, troubleshoot.
Orion open to vacuum due to some issue, dock, ride home in spacesuits.
Sucks, but hey, given choices, doable.
Can't capture to a hardlock upon docking for some reason, EVA over.





--
Greg Moore
Ask me about lily, an RPI based CMC.

On May 27, 3:47*pm, (Derek Lyons) wrote:
David Spain wrote:
Pat Flannery writes:

What if a Apollo couldn't make TLI?

What if CM/SM couldn't make TEI? Let's assume LM has
been used up.

Think of the movie 'Marooned' only in Lunar Orbit.
Anybody thinking of that possiblity in Apollo 2.0?

Or do we just not care?

There are some problems for which there are no solutions. *You do your
best to prevent that problem from occuring, but once you have done
that all you can do is just accept the possibility that it may happen,
and keep the number of a taxi service handy to get you home from the
saloon when it does happen.

D.
Apollo TLI was conducted with the S-IVb. The contingency plans for an
underburn (as of Apollo 11, at least) were to convert to an orbital
mission. Due to the low parking orbit, I would imagine that on a total
failure to light the S-IVb there would have to be a SM burn. In either
event, the SM would be used for retrofire.

Janitor_of_Lunacy wrote:

On May 27, 3:47*pm, (Derek Lyons) wrote:
David Spain wrote:
Pat Flannery writes:

What if a Apollo couldn't make TLI?

What if CM/SM couldn't make TEI? Let's assume LM has
been used up.

Think of the movie 'Marooned' only in Lunar Orbit.
Anybody thinking of that possiblity in Apollo 2.0?

Or do we just not care?

There are some problems for which there are no solutions. *You do your
best to prevent that problem from occuring, but once you have done
that all you can do is just accept the possibility that it may happen,
and keep the number of a taxi service handy to get you home from the
saloon when it does happen.

D.
Apollo TLI was conducted with the S-IVb.

True, but topic being adressed was TEI, not TLI.

D.
--
Touch-twice life. Eat. Drink. Laugh.

http://derekl1963.livejournal.com/

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL