Soyuz Lunar Mission

[DanM]

Hello Everyone

A while ago I read about how Space Adventures is planning to eventually offer circumlunar flights with a Soyuz. I've been trying to fly something like it in Orbiter with technology existing today, or that with slight modifications. My plan is to launch some sort of a booster, like an IUS or Block D on a modern heavy lift launcher like a Proton, Delta or Atlas. I'd have to add a docking collar to the booster. Then a Soyuz would be launched, and a LEO rendezvous would have to be performed. After docking, the TLI would send the stack into a free return trajectory. The booster would then be jettisoned and the Soyuz main engine for any corrections needed.

There are a few problems I have:
-What booster can provide the Delta-V?
-How do I add a docking collar to said booster?
-What modifications do I need to make to the Soyuz TMA from ISS v3.2?

Thank you!

 

[T.Neo]

I was thinking of something similar a few days ago, but more as a one-shot, urgent flight-to-the-Moon deal, with a manned landing, as opposed to a flyby-only comercial venture.

If I did things correctly, the Briz-M should have a dV capability, with Soyuz attached, of 4310 m/s... which is more than enough for a free return trajectory to the Moon.

I don't know how it would be launched... launching Proton with no payload sounds like a bit of a waste, but then again, the Briz-M is the payload.

Or would the launcher vibrate itself apart/accelerate too hard/destabilise?

 

[DanM]

I was thinking of something similar a few days ago, but more as a one-shot, urgent flight-to-the-Moon deal, with a manned landing, as opposed to a flyby-only comercial venture.

Have you read Moonseed by Stephen Baxter? Your idea sounds almost exactly like what they do in the book. That book sort of reignited (no pun intended) my interest in attempting such a mission.

And as far as using the Briz-M goes, now I just need to figure out how to add a docking collar and write the scenario. Exactly how much about programming do I need to know? I'm essentially illiterate on the programming and development aspects of orbiter.

Edit: I ran the rocket equation with the Briz-M and a full Soyuz, I got 3,578 m/s of Delta V. Am I correct?

where:

m0 is the initial total mass, including propellant.
m1 is the final total mass.
ve is the effective exhaust velocity. ve=Isp*g0 where Isp is the specific impulse expressed as a time period)
\Delta v\ is delta-v- the maximum change of speed of the vehicle (with no external forces acting)

m0 is 29,390 kg
m1 is 9,590 kg
ve is 3194.8 (specific impulse is 326 seconds, gravity is 9.8 m/s^2

My graphing calculator did most of the work, the natural logarithm is beyond my skill level, I only know advanced algebra right now, we're just getting to logs in my class.

 

[DanM]

Just a question, how do I add a docking adapter? Do I need to create a new mesh with the adapter and edit the config?

 

[Tycho]

Well, you could just add a docking point in the config file for the Briz-M if you're not one for visual accuracy. But if you wanted the visual, you'd have to edit the mesh file and add the appropriate docking point.

As for your mission concept, it's an interesting concept, I've never really thought of it. Now you've got my interest in such a mission sparked as well...

 

[N_Molson]

I already tried that.

a) 1st launch : ProtonM/DM2 with docking system
b) 2nd launch : SoyuzTMA
c) LEO rendez-vous
d) TLI
e) Lunar Pass
f) TEI
g) Undocking
h) Soyuz SA separation
i) Reentry

The problem is the last step. If you use Thornton's SoyuzTMA, you'll burn on reentry, whatever you try. Which is realistic : an thicker and heavier heat shield would be required for that kind of mission.

 

[Tycho]

Upon further research into Space Adventures' mission plan, it seems as though they'd be using a significantly modified TMA-M, or even a Soyuz ACTS, which is designed to be a lunar-capable Soyuz with a Fregat attached on the back. The website linked above seems to imply that a Block-DM powered TLI burn would, in fact, be possible with a Soyuz launch and a launch of a Proton with the DM on top. I would assume the aforementioned Soyuz crafts would have thicker and heavier heat shields.

I don't know, however, if the Block-DM (which by the way, includes a small habitation compartment) would provide enough delta-v for such a scenario.

 

[DanM]

The problem is the last step. If you use Thornton's SoyuzTMA, you'll burn on reentry, whatever you try. Which is realistic : an thicker and heavier heat shield would be required for that kind of mission.

How would one change that?

Well, you could just add a docking point in the config file for the Briz-M if you're not one for visual accuracy.

I'll probably stick with that for now

---------- Post added 12-26-10 at 03:06 PM ---------- Previous post was 12-25-10 at 09:55 PM ----------

I'm not very good with programming, so I need some help here. In the config, I can't really change anything about the vessel, do I need to edit the dll with a decompiler?

 

[Urwumpe]

I'm not very good with programming, so I need some help here. In the config, I can't really change anything about the vessel, do I need to edit the dll with a decompiler?

There is no such thing as a decompiler!

You need the sources (open source might by a famous keyword), to do that, and a compiler suite.

 

[Sky Captain]

The easiest way probably would be to use Unversal cargo deck to attach Soyuz to Earth departure stage.

 

[Urwumpe]

The easiest way probably would be to use Unversal cargo deck to attach Soyuz to Earth departure stage.

No.

The easiest way is called "Docking Adapter". You might have heard about it here or in another place.

(I find it pretty annoying that people think Universal Cargo Deck is the solution for every problem... that reminds me of the folly SAP/R3)

 

[N_Molson]

You also can use another Soyuz add-on, though you will lose realism.

There is another solution :

- a) Launch 1 : Proton/BlockDM -> Park the BlockDM in LEO
- b) Launch 2 : Proton/BlockDM2-1 -> Rendez-vous & docking between BlockDM & BlockDM2
- c) TLI : the Block DM2-1 burns all its fuel, the Block DM ignites one time to complete the burn if needed.
- d) Lunar Orbital Insertion of the BlockDM
- e) Launch 3 : ProtonM/BlockDM2 launch -> BlockDM2-2 in LEO
- f) Launch 4 : SoyuzTMA launch -> docking with BlockDM2-2
- g) TLI
- h) Lunar Orbit insertion
- i) Lunar Orbital Activities & undocking
- j) The SoyuzTMA docks BlockDM
- k) TEI
- l) The remaining fuel in the BlockDM is used to slow down the SoyuzTMA
- m) Undocking & SA Separation
- n) Survivable reentry (8000-10000 m/s range ?)

To brake the SoyuzTMA further, additionnal launches would probably be required. A complex mission plan, but I guess it would be very rewarding.

 

[Urwumpe]

Why not do a skip reentry? Maybe that tricks the damage algorithm to permit a safe landing at lunar speeds.

 

[N_Molson]

Maybe that would work in Orbiter, but since heat shields are made of ablative materials, that would not work in real life.

 

[Urwumpe]

Maybe that would work in Orbiter, but since heat shields are made of ablative materials, that would not work in real life.

It would - ablative shields don't work with too shallow reentries (because you would burn heat shield without using it to its full effectivity), but the Zond capsules used ablative shields just like Apollo, and Apollo also was designed for skip reentries (which had been found to be impractical for Apollo)

Zond also had a stronger heatshield than Soyuz, but well...it was ablative.

 

[N_Molson]

Yes, it would work with a thicker heat shield (more materials to burn) than the standard TMA :lol:

 

[DanM]

I just weighed using a Block D over a Briz-M. I'll probably go with the Block-D, instead. It has just enough Delta-V to reach escape velocity with a soyuz, and it has a higher specific impulse.

 

[Urwumpe]

Yes, it would work with a thicker heat shield (more materials to burn) than the standard TMA :lol:

Well, since heat shield mass is approximately proportional to reentry energy... no surprise

 

[DanM]

How do I thicken the heat shield of the soyuz from the addon? How do I make it more tolerant?

 

[Izack]

How do I thicken the heat shield of the soyuz from the addon? How do I make it more tolerant?

You can't; it wasn't designed with that in mind.