Soyuz Lunar Mission

[Urwumpe]

Fuel cell water is potable after a small amount of treatment. It is just hot after leaving the fuel cells and need to cool a bit in storage tank for drinking.

The three fuel cells of the Space Shuttle produce more than enough water for 7 astronauts, three much smaller fuel cells should have no problem supporting 2 astronauts.

back-up batteries are not needed, if we use an expendable "orbit keeping pack". If a fuel cell fails (which is unlikely) during the mission of the lander, we can still abort the landing on two fuel cells, instead of risking the life of the crew.

Important would be a good separation between the fuel cells (not repeating Apollo 13, in which a single failure "destroyed" all three fuel cells).

Dropping a fuel cell makes little sense, it means more weight for extra plumbing and special electrical components (power contactors) than the fuel cells weights. It would be better having an additional set of hydrogen/oxygen tanks on the landing part, that operates the fuel cells until ascent.

Lets plan for ten days and just assume we scale the power demands of the Shuttle down by crew size alone (which means luxurious amounts of electricity for ten days):

Oxygen: 669.5 pounds = 303.6 kg (includes oxygen for ECLSS)
Hydrogen: 78.85 pounds = 35.77 kg (includes hydrogen for fuel cell purge).

Every Space Shuttle fuel cells provides maximal 10 kW continuous DC power, by just scaling down, we would operate the spacecraft at maximal comfortable 8.5 kW continuous DC power (2.86 kW per fuel cell).

The LM needed just a tiny fraction of this.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090016295_2009014422.pdf

Note the slide saying, that the LM was initially designed for using fuel cells as well, coupled with a peaking battery and charger. Using batteries made the LM 43.5 kg heavier than the design with fuel cells, but had lower costs and less technological risk.

4 kW electricity maximal, and all together 65 kWh for a 35 hour stay on the moon.

So, batteries would really not cut it if we want to stay there for 10 days... but for ten days, our Lander would be a tiny bit small.

 

[Thorton]

About window, maybe up window doesn't really necessary since all active docking operations would be performed by Soyuz, because only it has active docking port with probe.

- Food (10 days, just in case)...
- Drinking water (10 days)...

It does have sense if we traveling to Moon with Lm from LEO, in our case however lander is able to support life only for 36 hrs.

2x LEVA suits

Since we use current tech, we could take Orlan-derived spacesiut, later it could be left on the moon before ascent. This scenario require 4 suit: 2 -Orlan, 2 - Sokol. Sokol is very light (10 kg), and i believe they can fit EVA role in case of emergency.


N_Molson, what program do you use for modeling? I have some ideas about lander, could you sent mesh to me?

 

[Wishbone]

Would you need an IMU for the lander?

 

[Urwumpe]

Would you need an IMU for the lander?

No, a strap-down INS could also do it, without the need for a stable platform. Such stuff is pretty reliable today, but not as accurate as a modern gimbaled INS. Also they consume more electricity, because they need to update much more often than a gimbaled INS needs (2000 times per second, compared to at least 60 times per second)

If we need perfection... well...

http://nuclearweaponarchive.org/Usa/Weapons/Airs.html

19000 parts, and one of the bigger ones costs $300,000

 

[N_Molson]

N_Molson, what program do you use for modeling? I have some ideas about lander, could you sent mesh to me?

Anim8tor, but that's only a concept for now, it has "bugs" (open meshes) & I haven't began to draw any details. I'll send it to you, though.

PS : + a few CO2 scrubbers (LiOH canisters...)

@Thornton : you should have received a PM with a download link

 

[Wishbone]

 

[Urwumpe]

(img)

Thats just Rate Gyros (measuring rotation rates). Three of these are needed for a strap down INS plus 3 acceleration sensors. The same number is also needed for a gimballing INS. You can also buy aviation grade INS from the shelf.

 

[Wishbone]

Yup. Will 1 kg be a good upper estimate (http://microsat.sm.bmstu.ru/e-library/DataSheets/data.htm)?

 

[N_Molson]

Of course, all the electronical systems must be able to endure an exposure to the void and very cold temperatures, since the module will be depressurized for LEVA...

Edit : + H2O vapor scrubber/recycler (to avoid ice condensation on electronics...), and the cosmonauts will necessarily produce H2O vapor (breath, sudation).

 

[Wishbone]

You could get around that by putting the compartment into a nitrogen-filled box with a decent leak rate. The idea of cooling off and then warming up the electronics doesn't make me enthusiastic.

 

[Urwumpe]

You could get around that by putting the compartment into a nitrogen-filled box with a decent leak rate. The idea of cooling off and then warming up the electronics doesn't make me enthusiastic.

That is so terribly outschool soviet technology, that only historic spacecraft designs (like Soyuz or Foton) still use it (without the leak, you use heat exchangers there). If you care about mass, you install electronics on cold plates and in the vacuum, and only have LRUs for avionics inside your spacecraft, that are vacuum hardened.

 

[N_Molson]

About the Sokols : it is specified they can't be used for EVA, because they tend to inflate when exposed to vacuum, allowing the wearer to perform very restricted moves only (press buttons / levers). Going through a small EVA hatch like the Soyuz one would probably need a depressurization (the way Leonov did it on Voskhod !). If a veteran cosmonaut could maybe save his skin (with probably sequels), a space tourist would probably not survive the process.

http://en.wikipedia.org/wiki/Sokol_space_suit#endnote_abramov

---------- Post added at 05:44 PM ---------- Previous post was at 05:35 PM ----------

The standard Orlan suit will be too rigid, I fear.

There was a modification intended for LEVA (1967)

http://en.wikipedia.org/wiki/Krechet-94

106 kgs, allows 10 hours of life support. Maybe some mass could be saved using the Orlan most recent components ?

The A7LB (Last Apollo missions & Skylab) weighted 96 kgs each. The latest Orlan (Orlan-MK) weights 120 kgs !

Orlan-MK suits :

Krechet-94 suit :

The EEMU (current EVA suit aboard the ISS) weights... 124 kg !

 

[T.Neo]

1967 strikes me as a tad... old?

Maybe a remake of the Orlan incorperating some of the structural wisdom from the Krechet-94 and even the Apollo suits and further NASA studies?

 

[Urwumpe]

I would say, we should get the proper space suits from the USA... nothing against the Orlan suits, but there is a reason behind why the EMUs are preferred on the ISS. You need a long camp-out for prebreathing pure oxygen (otherwise you risk divers disease), but can move WAY more comfortable in a EMU, while the Orlan is pretty stiff and exhausts you quickly. The prebreathing can be done inside the lander, we would just redesign all to 22 kPa pure oxygen. But we could then work without nitrogen tanks for the ECLSS, and use only helium as pressurization and pneumatic gas.

 

[N_Molson]

Well, Russian or American, the modern EVA suits are all over 100 kgs...

 

[Urwumpe]

Well, Russian or American, the modern EVA suits are all over 100 kgs...

Yes, but you can not avoid it. Reductions in EVA suit mass are serious engineering work, and using simply a pressure suit is suicide. They are not even designed for the thermal environment.

 

[Thorton]

OK, KVTK modeling has been finished, only dll left.

 

[Wishbone]

Urwumpe, thanks for the info. Do you mean Peltier effect coolers or radiators (fluid/two-phase)?

 

[Urwumpe]

Urwumpe, thanks for the info. Do you mean Peltier effect coolers or radiators (fluid/two-phase)?

State of the art technology are currently heat pipes - hollow pipes connected to a metal base plate and a larger radiator surface, that are filled with a liquid that evaporates already at low temperatures.

 

[N_Molson]

More info about the Fregat-SB (the extra tank is a torus after all !) :

http://www.orbiter-forum.com/showthread.php?t=20113

Thanks SiberianTiger ! :tiphat: