Lunar Lander in a 5.2m faring?

Fred J. McCall wrote:

[snip]
:The Russians have been transferring storable hypergolic fuel and oxidizer
:from Progress tankers to their stations (including ISS) for years. No EVA
r clumsy pressure fittings seem to be required for this to work.

Now you might want to look at the thrust developed and burn durations.
I don't see any of those vehicles going to the Moon, landing, and then
taking back off.

So let me get this straight:

scaling up from the several hundred kgs the russian progress routinely
transfers to the ISS http://www.russianspaceweb.com/progress.html to
the tens of tons required for a lunar mission is so complex that it
can't be possibly be finished until 2018.

But building a huge heavy lift vehicle out of shuttle components has
negible technological risk?

Orbital propellant transfer of storable propellants and even mild
cryogens such as liquid oxygen and liquid methane is not that hard.
There are even materials which remain flexible at liquid oxygen
temperatures, so you could use a simple bladder system. It is just that
nobody has ever seriously tried to do it.

But how can you get a descent lunar lander, capable of landing ~10 tons
on the lunar surface, into the 5.2m dimater faring offered by SpaceX
(or Boeing, LM, or the Stick)?

Can this be done without orbital assembley?

Sure. Why not. 5m diameter is plenty if you do not use hydrogen. Two 4m
diameter spheres filled with liquid methane and LOX would contain more
than enough fuel to land and launch quite a large payload on the moon.
You would just have to fill it up at a propellant depot in low earth
orbit.

One idea I had would be a lander that consists of two propulsion units
that would fit either side of the payload, and would be joined across
the top by a "bridge". The payload would fit in the middle, suspended
from the joining bridge. This bridge would be telescopic, enabling the
two propulsion units to be launched together inside a single faring.

I don't think that would be necessary. I like the skycrane approach
that is now proposed for advanced mars missions:
http://www.space.com/images/h_msl-skcrane_schema_02.jpg. Something
like this should work even better in the lower gravity of the moon.

Alex Terrell and to all others of this topic,
Why are you folks having to re-invent the fly-by-rocket wheel?
Obviously the entire NASA/Apollo fiasco isn't working out, now is it?

Personally I see nothing all that insurmountable about multiple
assemblies transpiring safely and efficiently in space. Haven't these
negative about everything fools ever heard of CAD engineering that's
been more than capable for creating end-results that are good to less
than 0.001", and of the "O ring" that can manage quite nicely with as
great as +/- 0.1"?

Even the tapered metal to metal joints, as in male tapered flange to
female tapered flange of non-O-ring methods is self aligning. So what
exactly is "Fred J. McCall" yapping about?

How Rockets Differ From Jets
http://groups.google.com/group/sci.s...107473b791e711
Engineering ain't magic, Tomcat.
This analogy should apply to many that claim that w/o documented
engineering that we've managed to fly-by-rocket lande upon and
EVA/moonsuit walked upon the moon, while forgetting six times out of
six to honestly photograph anything, forgetting to bring back any of
that extremely thin, colorless and highly retro-reflective layer of
"magic" clumping moon-dust, and even 6 times out of 6 expeditions
forgetting to bring back any moon atmospheric samples which should have
been loaded with the likes of sodium, radon and argon, as well as a
touch of O2 and dozens of other viable elements to boot. Christ
almighty, MESSENGER can't even include an honest look-see at the
natural dark colour of our own moon in their Earth flyby. Is all of
this MOS pathetic engineering magic or what?
~

Kurt Vonnegut would have to agree; WAR is WAR, thus "in war there are
no rules" - In fact, war has been the very reason of having to deal
with the likes of others that haven't been playing by whatever rules,
such as GW Bush.
Life upon Venus, a township w/Bridge & ET/UFO Park-n-Ride Tarmac:
http://guthvenus.tripod.com/gv-town.htm
The Russian/China LSE-CM/ISS (Lunar Space Elevator)
http://guthvenus.tripod.com/lunar-space-elevator.htm
Venus ETs, plus the updated sub-topics; Brad Guth / GASA-IEIS
http://guthvenus.tripod.com/gv-topics.htm

Rüdiger Klaehn wrote:
But how can you get a descent lunar lander, capable of landing ~10 tons
on the lunar surface, into the 5.2m dimater faring offered by SpaceX
(or Boeing, LM, or the Stick)?

Can this be done without orbital assembley?


Sure. Why not. 5m diameter is plenty if you do not use hydrogen. Two 4m
diameter spheres filled with liquid methane and LOX would contain more
than enough fuel to land and launch quite a large payload on the moon.
You would just have to fill it up at a propellant depot in low earth
orbit.


You also have the Transhab concept, which would also allow for the
volume contraints for the manned portion.

For that matter, I think you might also be able to manage a similar
form of inflatable tankage. There is no rule that the tankage has to
be metallic. There are several bladder systems that would work fairly
well.

You also have the Transhab concept, which would also allow for the
volume contraints for the manned portion.

That would definitely be a good idea for the manned portion. If people
are supposed to live and work on the moon for several weeks to months,
they will need some room. But the manned portion would be a separate
module.

For that matter, I think you might also be able to manage a similar
form of inflatable tankage. There is no rule that the tankage has to
be metallic. There are several bladder systems that would work fairly
well.
Of course you could do this. But it is not necessary for the first
mission since 5m diameter is more than enough to store lots of
propellant.

Might be a good idea for an orbital propellant depot though: Two
bigelow 330 modules adapted to propellant storage could store more than
100 metric tons of liquid methane and more than 300 metric tons of
liquid oxygen. That should be enough for several very ambitious moon
missions.

And with such a large diameter, an almost spherical shape and many
debris protection layers, boiloff should be minimal.

Charles Buckley wrote:
Rüdiger Klaehn wrote:
But how can you get a descent lunar lander, capable of landing ~10 tons
on the lunar surface, into the 5.2m dimater faring offered by SpaceX
(or Boeing, LM, or the Stick)?

Can this be done without orbital assembley?


Sure. Why not. 5m diameter is plenty if you do not use hydrogen. Two 4m
diameter spheres filled with liquid methane and LOX would contain more
than enough fuel to land and launch quite a large payload on the moon.
You would just have to fill it up at a propellant depot in low earth
orbit.


OK - so we have 2m of engine and 8m length of tankage, and the cargo is
now at 10m.

Whilst I beleive that LOX / Kerosene is the best propellant choice for
Earth launch and perhaps the EDS, I think LOX/LH2 is better for lunar
operations, because (OK, if) H2 and O2 can be obtained from the moon.

That's obviously why NASA's gone for methane!

You also have the Transhab concept, which would also allow for the
volume contraints for the manned portion.

Yes, but your transhab is now sitting at 10m above the lunar surface.

For that matter, I think you might also be able to manage a similar
form of inflatable tankage. There is no rule that the tankage has to
be metallic. There are several bladder systems that would work fairly
well.

Would propellant sloshing be a problem?

Rüdiger Klaehn wrote:
Fred J. McCall wrote:

[snip]
:The Russians have been transferring storable hypergolic fuel and oxidizer
:from Progress tankers to their stations (including ISS) for years. NoEVA
r clumsy pressure fittings seem to be required for this to work.

Now you might want to look at the thrust developed and burn durations.
I don't see any of those vehicles going to the Moon, landing, and then
taking back off.

So let me get this straight:

scaling up from the several hundred kgs the russian progress routinely
transfers to the ISS http://www.russianspaceweb.com/progress.html to
the tens of tons required for a lunar mission is so complex that it
can't be possibly be finished until 2018.
No. The only reason for the current envisioned delay to 2018 is to
allow a funding delay in developing a SDHLV due to the perceived need
to continue funding shuttle until 2010.


But building a huge heavy lift vehicle out of shuttle components has
negible technological risk?

negligable on-orbit technical risk, especially compared to on-orbit
assembly and fuel transfer operations. If shuttle and ISS have proved
one thing, it's that on-orbit technical risk should be traded for
ground technical risk wherever possible.


Orbital propellant transfer of storable propellants and even mild
cryogens such as liquid oxygen and liquid methane is not that hard.

says you.

There are even materials which remain flexible at liquid oxygen
temperatures, so you could use a simple bladder system. It is just that
nobody has ever seriously tried to do it.

Probably because it's just so simple. simple is boring... ;-)

Tom

In message
Fred J. McCall wrote:

"Jeff Findley" wrote:

Why do the feed lines have to be high pressure?

How does the fuel get into the engine? Little tiny men with buckets?

Pumps that come /after/ the connectors?

Anthony

Probably because it's just so simple. simple is boring... ;-)

Given that it is nasa we are talking about here, you might have a
point.

Remember the reasoning for picking the lockheed proposal for the x33?
They were basically arguing that the lockheed x33 required the most new
technologies and therefore would be most worthwhile to do.

The other proposals from rockwell and mcdonald douglas were too boring
for nasa, even though they might actually have flown.

(Henry Spencer) wrote:

:In article ,
:Fred J. McCall wrote:
::Maybe, but the simplest solution would be to launch the lander without
::any fuel tanks first, and then attach fuel tanks...
:
:And you're back to talking about assembly of pressure fittings in
:space. This is almost always a bad idea, particularly for relatively
:high pressure fittings like fuel feed lines.
:
:The Russians made it work quite routinely -- untouched by human hands --
:for refueling Mir (and, I believe, ISS) from Progress tankers. There's
:nothing that hard about it.

Depends on what your fuels are and how you get them to the engines.
So what you're proposing are gas-pressurized hypergolic fuel engines
with (relatively) low thrust?

ISS main engines, for example, only develop around 100 lbs of thrust
apiece. Mir engines are significantly larger, getting all the way up
around 650 lbs of thrust each.

--
"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