Simon_Jester wrote:And yeah. Minishuttles have big drawbacks. About the only thing I see going for them, really, is their reentry reliability (which I thought is supposed to be exceptional- I worry about that) and in principle reusability: buy one extra for 30 MB and you can use them for pretty much the entire late orbital and lunar program, where otherwise you'd be spending a good deal more on Apollo/Soyuz capsules.
I dunno, though.
Yeah, I think the big advantage of minishuttles is when you get them going early; then you start saving a lot more over the costs of replacing 2 and 3 man capsules. We haven't really done that, so the Lapot comes at a bit of a cost penalty over Soyuz at this point given the relatively limited number of flights we would make with either.
Actually, let me run the numbers real quick:
Lapot: Startup, 65 MB, Development, 140-175 MB (4-5 seasons, 5%-87%) Total 205-240 MB
Soyuz: Startup, 36 MB, Development, 50-75 MB (2-3 seasons, 40%-85%) Total 86-111 MB (the lower figure is only achievable if both Vostok and Voskhod are over 75% reliability; otherwise, with only Voskhod, Soyuz starts at 30%, which brings costs up towards the upper end.)
Let's also look at mission costs:
For a simple orbital mission with no other payload:
Lapot: A-series (3MB) + Booster (4 MB) + Lapot (0): 7 MB
Voskhod: A-series (3MB) + Booster (4 MB) + Voskhod (6 MB): 13 MB
Soyuz: A-series (3MB) + Booster (4 MB) + Soyuz (12 MB): 19 MB
Docking missions:
Lapot: Proton (12 MB) + Booster (4 MB) + DM (2 MB) + Lapot (0): 18 MB
Voskhod: A-series (3 MB) + Booster (4 MB) + DM (2 MB) + Voskhod (6 MB): 15 MB
Soyuz: Proton (12 MB) + Booster (4 MB) + DM (2 MB) + Soyuz (12 MB): 30 MB
Joint docking missions:
Lapot: A-series (3 MB) + A-series (3 MB) + Booster (4 MB) + DM (2 MB) + Lapot (0): 12 MB
Voskhod: A-series (3 MB) + A-series (3 MB) + Booster (4 MB) + DM (2 MB) + Voskhod (6 MB) : 18 MB (though there's no good reason to do this)
Soyuz: A-series (3 MB) + A-series (3 MB) + Booster (4 MB) + DM (2 MB) + Soyuz (12 MB): 24 MB
But then we get to the lunar missions:
Lunar Pass:
Lapot: Proton (12 MB) + Booster (4 MB) + Kicker-A (3 MB) or Kicker-B (6 MB) + Lapot (0): 19 MB (22 with Kicker-B)
Voskhod: Proton (12 MB) + Kicker-A (3 MB) + Voskhod (6 MB): 21 MB
Voskhod Kicker-B: Proton (12 MB) + Booster (4 MB) + Kicker-B (6 MB) + Voskhod (6 MB): 28 MB
Soyuz: Proton (12 MB) + Soyuz (12 MB): 24 MB
Historical Lunar Orbit LM tests and Landings:
Lapot: N1 (18 MB) + Booster (4 MB) + Kicker-B (6 MB) + DM (2 MB) + Duet (8 MB) + Lapot (0): 38 MB
Voskhod: N1 (18 MB) + Kicker-B (6 MB) + DM (2 MB) + L-3 (9 MB) + Voskhod (6 MB): 41 MB
Soyuz: N1 (18 MB) + Soyuz (12 MB) + Duet (8 MB): 38 MB
Joint EOR:
Lapot: 2x Proton (24 MB) + 2x Booster (8 MB) + Duet (8 MB)+ Kicker-B (6 MB) + DM (2 MB) + Lapot (0): 48 MB
Voskhod: 2x Proton (24 MB) + Booster (4 MB) + L-3 (9 MB) + Kicker-B (6 MB) + DM (2 MB) + Voskhod (6 MB): 51 MB
Soyuz: 2x Proton (24 MB) + Duet (8 MB) + Soyuz (12 MB): 44 MB
Joint LOR:
Lapot: 2x Proton (24 MB) + 2x Booster (8 MB) + Duet (8 MB) + 2x Kicker-A (6 MB) + DM (2 MB) + Lapot (0): 48 MB
Voskhod: 2x Proton (24 MB) + Booster (4 MB) + L-3 (9 MB) + 2x Kicker-A (6 MB) + DM (2 MB) + Voskhod (6 MB): 51 MB
Soyuz: 2x Proton (24 MB) + Booster (4 MB) + Duet (8 MB) + Kicker-A (3 MB) + Soyuz (12 MB): 51 MB
So we can see that though the Lapot outperforms cost-wise in the earlier missions, there are fewer savings to be found later on, and in fact in the Joint EOR, the Soyuz is actually cheaper! But since we are past the earlier missions already, Lapot is now a poor choice, especially as it would force on us the extra development costs of the Kicker-B. Still, we do have that agreement to honor...