Phobos ISRU based LOX-LH2 mission architecture

Quaoar · 2014-03-11 10:45:16

Many evidence suggest that Phobos and Deimos are rich of water in the form of buried ice protected by water rich clay permafrost

http://www.uapress.arizona.edu/onlinebk … rces31.pdf

If these evidences will be confirmed, it will be more simple to refuel on Phobos an orbit-orbit vehicle than to land on Mars the whoole spaceship, refuel it with local produced LOX-LCH4 and bring it back to Earth, like in Mars Direct.

F9+lander+layout.png

So we can imagine a colonization plan driven by a Phobos base, connected to Mars sufrace via LOX-LH2 reusable shuttle landers (like the above GW Johnson's design).

Last edited by Quaoar (2014-03-11 10:50:31)

GW Johnson · 2014-03-11 14:29:05

Hi Quaoar:

Glad you liked my "landing boat" design. I didn't look at the benefits of mining water on Phobos (or Deimos), but you are correct. Anything not in a gravity well is easier to do. If you have the right equipment with you.

I know there is evidence to support the existence of water at several locations on Mars, and in a lot of small bodies like the Martian moons. The only problem is, you cannot count on it being true, until you've been there and found out for sure. That's "ground truth".

Over the decades, an awful lot of what we thought we knew from remote sensing actually turned out to be wrong. Prior to Mariner 4 in 1965, we thought it was pretty certain that Mars had a nitrogen atmosphere with a little CO2 as a secondary component, and a surface pressure near 85 mbar. Winged airplanes were thought to be possible on Mars. Boy, was that ever wrong!

After 1965, we pretty well believed Mars was rather airless and very much like the moon. Until, we put Mariner 9 in orbit in 1969. Boy, were we ever wrong again! And the history has been like that ever since, just not quite as extreme from one discovery to the next discovery. We're homing-in on the truth. We're not there yet.

Gross features like the weather reports I believe. Atmospheric composition, too. Maybe not so much the inferred subsurface conditions. There's ice (we've seen it), but no one yet knows how much, or how much it can be concentrated or dispersed, or admixed with "other stuff", at any given site. The history of sites here on Earth is wildly different from site to site, even in the same general type of terrain. Why would it be any different there?

And we won't know the answers to questions like that until people have actually been there for a while. Myself, I hate betting lives on answers to the unknowable. So, I tend to take everything necessary from home, until we find out "for sure" that the answer is what we thought, or something different.

That's what I call "suspenders-and-belt, and armored-codpiece" thinking. It's what you have to do to make sure that the crew comes home alive and in decent health.

GW

Quaoar · 2014-03-12 06:52:31

GW Johnson wrote:

Hi Quaoar:
Glad you liked my "landing boat" design.

I was very impressed by your site: is a source of very interesting ideas and innovative concepts.

GW Johnson wrote:

I didn't look at the benefits of mining water on Phobos (or Deimos), but you are correct. Anything not in a gravity well is easier to do. If you have right equipment with you.

Even without use Mars moons for ISRU (at the first mission we cannot have the groud thrue to realy on it), it may be convenient to use the modular spaceship "Johnson Express" to travel from Earth-Moon L2 to Deimos orbit, for saving propellant.

F15+fleet+concept.png

Your landers, with dead end propellent tanks, may travel from Deimos orbit to low Mars orbit, leave there one or two fuel tank for the return, and landing on Mars. When the surface missions are finished, the landers will ascent to LMO, rendez-vous with the tanks, refuel and trasfer to Deimos for the rendez-vous with the mother spaceship.
Starting from Deimos orbit, the mother spaceship will change plane, low the pericenter at LMO altitude, fire the rockets when is close to Mars and insert in a Earth transfer orbit in economy.

So in one mission we can explore Deimos and Phobos for prospection and 6 surface sites on Mars: if water has been found on the moons, the next mission will bring the equipment for LOX-LH2 production and storage.

GW Johnson · 2014-03-12 10:55:43

Myself, I'd bring examples of all my ISRU gear, and try it out at all sites visited. Chances are, there will be one site where it actually worked the best. That's the one to select as a base, and leave the equipment there, and operating robotically. My concept takes enough stuff to do the basic mission, even if every piece of ISRU fails. That way, ISRU-produced supplies and propellants are a bonus that "fuels" even more explorations beyond the baseline design. That's "win-win with no lose".

That's also why I broke my visit into two phases. The first visits multiple sites, based from orbit, to find that best one. The second phase lands everyone and everything there to establish that base and try it out. Something like 6 months in each phase. I was envisioning a base on Mars, but if Phobos is better for making oxygen, propellants, and water, then that's where the base should be.

I did use something closer to 60 cu.m than 90 cu.m per person sizing out my landers. There's something like 200 cu.m for a lander crew of 3 available as two pressurized decks. The abort capsule looks an awful lot like a manned dragon, with less heat shield but a set of legs. It'll get them down alive, where another lander can go to pick them up. I used shell panels on the lander that fold out to become load/unload ramps. There's a lot of space around the engine compartment on that lowest deck to hold massive amounts of bulky gear and equipment. Load/unload is a serious logistical issue for people in spacesuits.

3 landers on the surface with 200 cu.m each, with the whole crew of 6, pretty well meets the 90 cu.m per person living space criteria for a long (6-month) stay on the surface at the selected base. The double habitat module of the orbit transfer vehicle also pretty well meets the same criterion for the 7-8 month transfers to and from Mars. I had in mind two great big Bigelow inflatables, just with different cores that fold out inside when deployed.

The real trick is not mounting stuff on your pressure shell wall, whether you are inflatable or not. Leave the gear in a fold-out core. That way you can find and seal punctures quickly, before the module can depressurize. That's one of the lessons from Mir, by the way. They could never find the leak, too much crap in the way. So they lost the module. They're lucky they didn't lose a crewman.

GW

Quaoar · 2014-03-12 13:45:21

GW Johnson wrote:

The real trick is not mounting stuff on your pressure shell wall, whether you are inflatable or not. Leave the gear in a fold-out core. That way you can find and seal punctures quickly, before the module can depressurize. That's one of the lessons from Mir, by the way. They could never find the leak, too much crap in the way. So they lost the module. They're lucky they didn't lose a crewman.
GW

It's the same for sail boats: in a well projected boat, all the hull has to be free from crap to find and fix any possible leak before sinking.

Last edited by Quaoar (2014-03-12 13:46:52)

GW Johnson · 2014-03-13 08:10:58

True, true! Well-said, Quaoar! Spacecraft designer's NB: never ever, ever obstruct access to your pressure shell. You must be able to reach and fix leaks in seconds!

GW

SpaceNut · 2018-01-14 10:47:11

A first mission set up for refueling capability in mars orbit for BFR alternative and other missions outward if thats our choice.

louis · 2018-01-14 16:50:00

Just a diversion of focus and energy in my view. We need an Apollo-style focus on the prize. I think Musk has that. Whether he grabs the prize in 2024, 2026 or 2028, I think he will do it. He won't do it by diverting to Phobos.

SpaceNut wrote:

A first mission set up for refueling capability in mars orbit for BFR alternative and other missions outward if thats our choice.

SpaceNut · 2018-01-14 19:02:39

Well it would be better than a flyby of mars. At least we would be able to get out and stretch our legs a bit before going home.

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#1 2014-03-11 10:45:16

Phobos ISRU based LOX-LH2 mission architecture

#2 2014-03-11 14:29:05

Re: Phobos ISRU based LOX-LH2 mission architecture

#3 2014-03-12 06:52:31

Re: Phobos ISRU based LOX-LH2 mission architecture

#4 2014-03-12 10:55:43

Re: Phobos ISRU based LOX-LH2 mission architecture

#5 2014-03-12 13:45:21

Re: Phobos ISRU based LOX-LH2 mission architecture

#6 2014-03-13 08:10:58

Re: Phobos ISRU based LOX-LH2 mission architecture

#7 2018-01-14 10:47:11

Re: Phobos ISRU based LOX-LH2 mission architecture

#8 2018-01-14 16:50:00

Re: Phobos ISRU based LOX-LH2 mission architecture

#9 2018-01-14 19:02:39

Re: Phobos ISRU based LOX-LH2 mission architecture

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