Soyuz Lunar Mission

[N_Molson]

The large Russian cryogen upper stage will do that.

Which one ? The KVRB ? The idea is to use already proven technology, so if we had to try another booster, it seems that the Centaur, launched by an AtlasV, would be the most appropriated, after all we could imagine an international cooperation for this kind of mission. But in the perspective of space tourism, that would boost the price of the flight.

"KVRB cryogenic kick stage was to be completed by the end of 1995 (competing against motor by CADB). However no production decision ever taken. Technology instead used in 12KRB cryogenic upper stage for the Indian GSLV launcher."

 

[Urwumpe]

Which one ? The KVRB ? The idea is to use already proven technology, so if we had to try another booster, it seems that the Centaur, launched by an AtlasV, would be the most appropriated, after all we could imagine an international cooperation for this kind of mission. But in the perspective of space tourism, that would boost the price of the flight.

"KVRB cryogenic kick stage was to be completed by the end of 1995 (competing against motor by CADB). However no production decision ever taken. Technology instead used in 12KRB cryogenic upper stage for the Indian GSLV launcher."

I would say that can be called proven technology, since the 50% failure rate of the GSLV comes from Indian components. Often it can't launch because a cow is sleeping in the flame trench.

 

[Thorton]

Well, if we all agree to consider KVRB as proven technology :hmm: i could make it. At least there were some plans to use KVRB on the Proton.
Besides with cryo tug we will get another challenge, due its very limited operational time docking should be done very quickly.
As the alternative we have KVTK, but it is only a project, however its engine (RD0146) already has been created.

 

[Urwumpe]

Well, if we all agree to consider KVRB as proven technology :hmm: i could make it.
Besides with cryo tug we will get another challenge, due its very limited operational time docking should be done very quickly.

Could could install a sun shield on its outside hull for such docking missions, which keeps the fuel in shade, like the USA plan for their recent lunar program...

 

[N_Molson]

OK, lets go for the KVRB if you think it's possible to adapt it on a ProtonM.

Here's my first draft of a Lunar Module, in the concept it's more-or-less a TMA BO atop a Fregat.

I have no idea of which engine could be used, though. It needs to be throttleable to very low levels and to ignite on demand.

The green sphere is the habitation module. A little smaller than the Soyuz BO, but not much. Not a lot of room inside, but what we want is a light lander, our cosmonauts won't have to spend two weeks on the Moon. I guess two people could fit in, a pilot and a space tourist for exemple. The "forward" grey thing is the viewing bay. The "rear" grey thing is the hatch. The module has to be depressurized, no room for an airlock.

Below, there is be a central "cylinder", supposed to house the main engine (would be defined as "hover"), and probably an internal tank for liftoff. The yellow "balls" are external fuel tanks (no idea of the capacity needed yet). The two platforms are mostly needed to attach the legs (an articulated attach arm would be needed on the lower platform).

After liftoff, the sphere and the central cylinder would detach from the platforms + tanks. This ascent stage could really be a lightweight (2 tons maybe).

 

[mc_]

Looks very similar to this: http://astronautix.com/craft/lk.htm

 

[N_Molson]

Here's another proposal : instead of the Soyuz BO, we use an ACTS-like BO. More internal volume, maybe better suited for 2 cosmonauts. Allows a "true" door, of 1.7*1 meters, would make the EVAs easier. Looks more "modern", will be also heavier.

The black thing on the front is a small cupola. The docking port is still on the top. The cylinder is 2 meters high, + 0.5 meters for the upper conic "docking" section.

 

[mc_]

You mean, that Soyuz don't have BO itself, but lander's "habitation module" is the Soyuz BO, and acts like BO while travelling to the Moon and back?

 

[N_Molson]

No. I mean it would be based on an existing habitation module concept. Which is the BO. The idea is not to build a vehicle from scratch, but to use existing (russian) designs, in the perspective of a "space tourism-funded" mission.

 

[Urwumpe]

I think the Soyuz BO could be large enough for two astronauts, it is pretty comfortable even for three, you just need to move all the other stuff outdoors..

Also, do we assume vacuum hardened subsystems or do we need to put most stuff of the lander into pressure vessels?

 

[T.Neo]

Also, do we assume vacuum hardened subsystems or do we need to put most stuff of the lander into pressure vessels?

Weren't the subsystems designed- at least orginally- to survive in a vacuum with the orbital module depressurised? Or have they all been replaced with modern, non vacuum hardened systems?

I still don't like the pressurised module setup. I know it's far safer and more convenient (from a crew perspective), but the minimalist in me still has an urge to disregard the astronauts and save on mission architecture. :shifty:

 

[Thorton]

Don't you think this is a very huge door? Especially for such small spacecraft, i think LM sized door would be better, it could save some mass.


Also looks like tanks should be bigger, but at first we need to define mass of the habitation module with all subsystems and then calculate required volume for fuel tanks.

 

[Urwumpe]

Don't you think this is a very huge door? Especially for such small spacecraft, i think LM sized door would be better, it could save some mass.


Also looks like tanks should be bigger, but at first we need to define mass of the habitation module with all subsystems and then calculate required volume for fuel tanks.

Exactly. But it for making that well, we should define, how many astronauts we want to land on the moon for how long. Then we can put an upper limit to the habitat mass.

EDIT: BTW, would it be impossible to ask Anatoly Zak for the mesh data he used for rendering this? Would make a nice spacecraft in orbiter...

 

[T.Neo]

Not two astronauts? A pilot and a participant?

Apollo 17 spent around three days on the Moon, but that might be too long... maybe an Apollo 11-length stay would be better.

 

[Thorton]

Yes, i think our LM should be able to support 2 cosmonauts at least 24 hours.

BTW, would it be impossible to ask Anatoly Zak for the mesh data he used for rendering this? Would make a nice spacecraft in orbiter...

Taking into account that he sells his work i don't think he could give us this mesh, but i could ask anyway.

 

[Urwumpe]

Yes, i think our LM should be able to support 2 cosmonauts at least 24 hours.

Agreed. That means about 16 hours on the surface of the moon.

Taking into account that he sells his work i don't think he could give us this mesh, but i could ask anyway.

Yeah, asking doesn't cost anything, and if he wants to produce his own simulations... :thumbup:

 

[N_Molson]

Don't you think this is a very huge door? Especially for such small spacecraft, i think LM sized door would be better, it could save some mass.

Agreed

Yes, i think our LM should be able to support 2 cosmonauts at least 24 hours.

Makes sense to me, I guess we could strech this to 36 hours, as a safety margin (if for some reason the Lunar Orbital Rendez-vous is delayed).

I like Zak's Lander, especially the cabin with windows both for docking and landing. I wonder if we should include solar panels, what do you think about it ? Don't forget that, unlike the Apollo missions, we send the LM "forward" in lunar orbit. Maybe a minimal solar power supply would be needed to keep the systems "in sleep mode but alive", and to keep the batteries at full charge.

OK, now about the mass budget :

- Are we going to use a second KVRB ? What is the LLO payload of that tug ? Maybe a DM3-L would be enough (and cheaper ?).
- dV : the Eagle module had 2470 m/s dV for descent and 2220 m/s dV for ascent. It proved to be the right numbers, since Armstrong had only a few seconds of propellant left when he landed !
- Subsystems : we have to make an exhaustive list. Water & LOX quantities (but also N2, for pressurization) are important parameters for the LSS (life support system), navigation electronics and communications hardware is going to be way lighter than it was in the '60s, but still it will have some mass. Of course, the heaviest system will be the engine(s?)+the propellant...
- Hardware for lunar EVA : suits (1 spare maybe ?), a few tools, high quality cameras (our tourist wants to get perfect pictures & movies for the price he paid !), 2 flags (1 for Russia, the other for the turist country, maybe some experiments if the cosmonaut has enough time (and energy !) to carry them.

Edit : the eight "yellow tanks" I put on the lander have together a capacity of 14,137 m3.

 

[Urwumpe]

- dV : the Eagle module had 2470 m/s dV for descent and 2220 m/s dV for ascent. It proved to be the right numbers, since Armstrong had only a few
seconds of propellant left when he landed !

Agreed, that makes sense.

- Subsystems : we have to make an exhaustive list. Water & LOX quantities (but also N2, for pressurization) are important parameters for the LSS (life support system), navigation electronics and communications hardware is going to be way lighter than it was in the '60s, but still it will have some mass. Of course, the heaviest system will be the engine(s?)+the propellant...

The Russian spacesuits should be what defines what atmosphere we use in the lander. Same pressure and same composition, but should be able to be equalized to the Soyuz pressure.

The engines should be about as heavy as the navigation gear eventually, since the engines aren't really powerful. But proper navigation for a lunar landing involves altimeters (laser/radar) and a good IMS, as well as star trackers for alignment. Including power distribution and thermal control, the avionics should be as heavy as the engines.

Most mass will only be fuel before landing...afterwards we are dry.

- Hardware for lunar EVA : suits (1 spare maybe ?), a few tools, high quality cameras (our tourist wants to get perfect pictures & movies for the price he paid !), 2 flags (1 for Russia, the other for the turist country, maybe some experiments if the cosmonaut has enough time (and energy !) to carry them.

No spare suit needed, those weight a lot and are not needed 99% of the time. If a suit requires more than superficial repairs before landing, we should simply abort the landing. But that happens rarely.

Food! Don't forget food.

Also I think we should use a fuel cell for electricity, since it makes a lot of the stuff easier if we want to reduce mass. Modern fuel cells come off the shelf and are pretty light.

 

[Thorton]

Also I think we should use a fuel cell for electricity, since it makes a lot of the stuff easier if we want to reduce mass. Modern fuel cells come off the shelf and are pretty light.

But as i remember fuel cells could function no more than 2-3 weeks, the lander however must be able to stay on LLO longer. In this case solar panels would be more suitable.

Are we going to use a second KVRB ? What is the LLO payload of that tug ?

I still cant find payload capabilities for KVRB, but i hope 1 KVRB will be enough.
We can calculate this, right after we will know total mass of the lander.

Urwumpe, could you estimate needed amount of consumables for 2man/36 hours stay?

 

[Urwumpe]

But as i remember fuel cells could function no more than 2-3 weeks, the lander however must be able to stay on LLO longer. In this case solar panels would be more suitable.

But it would function in deep hibernation there, with most subsystems disabled. It would need only a fraction of the electricity most of the time, which could be provided by batteries... every few days, the lander is activated by radio command from Earth, powers up the fuel cell, corrects its low orbit (if needed at all), recharges the battery, and powers down again for hibernation.

If we use solar cells, we would need to design the battery capacity for the phases in which we can't use the solar cells at all: Landing and ascent. Those are sadly the phases which consume most electricity.