New Mars Forums

A criteria to consider would be the Martian heatshields.  In the VSE architecture one bonus the CEV capsule has over the shuttle, and like the Apollo for that matter, is that the heat shields were protected.  Now, I noticed, in most architectures, even in Zubrin's renowned Mars Direct, the heat shields are wide open for anything ranging from LEO space junk to metoroid showers to punch a crack.

This is a worry that will HAVE to be addressed; not so much because of engineering but because the media press, with the CEV specs in mind, will, like naively-blunt Kindergardners, almost instantly point to the big fancy heat shield being toted at the front of the Mars armada and embarass the hell out of the NASA engineer stuck in the hot seat.

I think what would need to be developed are the Mars vehicles.  Beyond perhaps propellant tanks they will be creatures of a different sort from any on the Moon.

I'd like to model the architecture as much as possible off the Mars Semi-direct architecture Zubrin created as a "compromise" that later led to NASA's "Reference Mission."  I can see the CEV as being the orbiting ERV from Semi-d; I think however we'd have to recalculate how much propellant it'd need for the return half of the voyage where it'd come into play.

The Mars Habitat could be the initial manned lander brought along with the CEV and then there'd be the Mars Ascent Vehicle, which in Semi-d brought the ISSP equiptment and power sources.

If the CEV were to be 'blended' with Semi-d, upon arriving at Mars it'd most likely have to seperate and break into a high parking orbit automated and solo (which it is capable of) while the Mars Habitat Lander first aerobrakes and then lands with the crew with it.  In both Semi-d And Mars-d, should something happen to the ERV the crew wait on Mars in relative safey doing field research as opposed to the complete vaccum of space doing nothing, so if CEV blows in orbit just send another.  The Mars Ascent vehicle would be closer in aspect to the original version in Mars-d to reach the high parking orbit and draw on ISSP to maximize its use while minimizing the ERV/CEV's propellant loads for orbital breaking and escape.

To test some of this, a large test probe carrying at least a model of the Crewed Mars Lander shields ought to be sent; to aerobrake first into orbit and then land from orbit.  Possibly an unmanned CEV could be sent to test break into Martian orbit and then leave as well.

We ought to rename this topic the "Best Outer Planets' Moons To Send Crew". 

Ok I'll make my list up:

Jupiter:  Callisto, dull as it is but I have to admit the low-radiation threat can't be ignored.

Saturn:  Titan - I don't see the atmosphere as a burden but a blessing.  It could be used for aerobraking which can't be done on the airless moons, you get methane fuel from the air itself w/o processing, it doesn't have the huge radiation threat the Galilean moons of Jupiter bear (at least not to my knowledge), and outside the rings of Saturn it is itself the biggest science target here.

Uranus: Tough choice.  Miranda is the science moon but those canyons aren't good landing spots, so I'd vote for Titania since its the largest.

Neptune: Triton since it is pretty much the only major moon.

On this topic I thought to mention the upcoming Phoenix lander being build out of Arizona.  Technically its not a rover but it is going to be digging for ices in the soil and off and on I hear talk about a drilling mechanism if not for it than possibly a successor lander.

How much work will be debateable, but either way work needs to be done so its a "damned if you do, damned if you don't" situation in short.

However...NASA will damn itself moreso if it backs out now and returns to the original "reuse the shuttle until we burst all our astronauts into flame" senerio.  If it comes out a billion overrun I would be willing to look the other way...however if it gets into 5+ billion overrun definetely take concern.

The plan is not flawed, neither is the CEV.  To me its the best compromise using what we got now with what space advocates...at least those with a sensible brain (such as Zubrin on one of his more sane days)...have been preaching and begging for years on end.

Rutan and his commercial bretheren are promising...but at this moment they're not up to much more beyond taking tourists on costly trips.

Eventually NASA will have to select sites for planetary bases as the VSE advances and both scientists and engineers press for off-Earth sites of operation.

Feel free to suggest where would be ideal locations for sites of human settlement on either Mars or Luna.  Try to cite merits on accessibility from orbit, resource potential, science potential, safety, and anything else that'd merit considering such a locale for a human base. 

I'll make the first suggestions of course. 

For Luna:  Since water is scarce the lunar poles are likely candidates.  I will be more specific and say de Gerlache crater in the South Pole-Aitken basin.  It itself is one of the craters believed to hold polar ice.  The basin as a whole due to its depth into the crust offers great potential for lunar geological science and even sampling the lunar mantle.  Resource extraction including ice (if cornfirmed naturally), metals, and LOX are possible so for creating a self-sustaining lunar colony it's prime relstate.  The down sides are the terrain, which is cratered, and the extreme southerly position imposing orbital maneuvering.

For Mars:  Kasei Vallis is the planet's most impressive channel system on the planet, and even if it was a short-lived mass flood it lead from the northern basins almost directly into Mariner Valley itself - if you want research on ancient hydrological cycles you can hardly get better or finding sites for Martian fossils.  It is also adjacent to numerous locales: to the East Chryse where Viking 1 sits, to the South the glory of Mariner Valley with the network of the Layberinth of the Night to the Southwest, and to the West not just Olympus or even the Tharsis Mons but numerous volcanoes.

Between what's being reported it sounds almost like its anyone's guess how well a 5-segment SRB will perform.  A 50/50 senerio, figures...

I think this is where the actual engineering tests will solve things.

If it is simply intermixed with the dust it may be easy to gather.  Essentially you use a beefed-up rover with a snow shovel and collection baskets to the sides.

Once collected the dust would have to be sorted as much as possible.  A good-old-fashion sifter in one form or another at least.  This may vary depending on the exact form of the ice which makes identifying it beforehand definetely vital.

Taking the portion of the dust that is primarily ice then you simply thaw it, either directly with solar light or in a microwave powered by solar panels.  Once liquid pump the water through a filter to eliminate the final bits of lunar dust.

As for what to do with the water just store it as H2O I say.  In that form alone there'd be plenty of uses for it at a lunar base.  Any cryogenic H2 or O2 should be meant as short-term storage for immediate launches otherwise we'd be wasting water - only use electrolosis to break it up when we absolutely need to.  It takes more effort and energy even in the shaded regions of the moon to keep O2 and H2 at those temperatures so, again, only when nessicary.

Now if the ice is intermixed with solid rock, which hopefully isn't as likely, then we'd need even tougher equiptment; certainly an automated jackhammer at least.  Add rock crushers to the aforementioned extraction process and it'd be mostly the same.

I agree G.  Its not an unreasonable architecture that is simply getting the minor details filled in is all.  Again its better to build something than not to go at all as you said.

It doesn't sound completely unnerving.  The CEV diameter is being maintained and if they can minimize the size of something while maintaining priorities then there's no problems.

Looking at the picture the whole spacecraft looks a little 'dumpier' but hey, size isn't everything.  The CEV is meant first and foremost to carry crew safely to and from the Earth - anything else is secondary.

A bonus of a smaller SM would be to the LSAM, which is already tasked to perform the trans lunar burn with the EDS, leaving more room for exclusively lunar equiptment and propellant.

So again this doesn't mean any inherent problems right away.

Right.  Testing with 4-segments isn't nessicarily bad -it would at least give engineers an idea how the vehicle would behave relistically in flight.

I'm willing to try the stick, but if it proves too complicated switch to the lower stage of the CaLV.

For a Reuseable LSAM concept we ought to establish several bare minimums so the purpose of the vehicle isn't skewed too horrifically.

1) Exclusively for crewed vehicles.

- The only reason today that spacecraft return to Earth is to retrieve samples for more intensive study on Earth and, for more obvious reasons, to return men and women safely back to Earth.  With scientific equiptment and laboratories being established on the lunar surface and geologists coming for "hands-on-research" the need to bring back lunar samples diminishes quickly.  A cargo vehicle's purpose is to deliver the maximum amount of cargo; for reuseability you have to sacrifice a solid portion of that cargo capacity - which is why the shuttles are no longer in the buisness of delivering even military satellites into orbit.  If a VSE cargo-exclusive lander can deliver a few tens of cargo to the Moon, its purpose it done with no need of extensive redesign.  Also...why would we bring LOX from the Moon?  Why to lower propellant cost and breathable atmosphere.  But if people are on the Moon, there's no need to take it beyond lunar orbit, and if our limit is lunar orbit then we just load up the RLSAM with our LOX.  No reuseable unmanned landers period.

2) Optimized for operations in lunar space.

- Once its brought to lunar orbit the RLSAM is in its element.  Taking it anywhere beside the Moon itself is not just unessicary but wasted effort.  A lunar lander is meant to deliver people to and from the Moon.  In both the old Apollo and VSE architectures the lander is dumped anyway once the crew is ready for the trip Earthward.  If it is reuseable may as well keep it there, but nothing like flimbsy heatshields ought to be added at all.

3) Supplemented by LOX.

- If we have to constantly send all the propellants to the Moon it undermines the benefits of the RLSAM, so at the very least we should eliminate oxygen out of the equation.  Possibly H2 from Lunar Ice but that's still iffy, but LOX should be possible to establish with expendable landers and then utilized by reuseable ones.  The benefit of RLSAM is to reduce the mass needed from Earth - adding LOX further reduces it.

4) Realistic reuseability.

- GCNRevenger pointed out the innevitable damage caused by radiation and even micro-meteoroids.  And as the shuttle itself has taught us a vehicle can only be reused so many times.  The autonomous Progress is used once as will ESA's ATV, but surely more flights could be done than that.  I suggest conservatively 5 to 10 reuses before 'retiring' a lander on the Moon.  Even then its a piece of equiptment not mere garbage, so once on the Moon canibalize the crew compartment while saving the fuel tanks.

Anyone want to make suggestons, further amendments to this RLSAM 'draft'?