Who needs orbital speed when you could design a Fulton recovery system for the vacuum of space? (sarcasm)To this armchair rocket design quarterback, it doesn't look realistic.
- Sure, lunar gravity is only 1/6 of a gee, and yes, there's no drag. But still, could a booster small enough that we don't see it in the video possibly get two guys in space suits up to the CSM's altitude? I doubt it. And match the CSM's orbital speed? I very much doubt it.
- What about attitude control and guidance?
- Does the CSM have any EVA capability? It's not like picking up a hitchhiker.
Delta V of 1.7km/s without an atmosphere and with only 1/6 of the gravity loss of an Earth launch should make for a fairly small vehicle. It looked fairly realistic to me, even before I found the Wikipedia article, which has some good details: Lunar escape systems. GNC was evidently very stick-and-rudder. The CSM did have EVA capability, BTW, and it was used on at least the last three lunar missions to retrieve experiments from the service module during the ride home.To this armchair rocket design quarterback, it doesn't look realistic.
- Sure, lunar gravity is only 1/6 of a gee, and yes, there's no drag. But still, could a booster small enough that we don't see it in the video possibly get two guys in space suits up to the CSM's altitude? I doubt it. And match the CSM's orbital speed? I very much doubt it.
- What about attitude control and guidance?
- Does the CSM have any EVA capability? It's not like picking up a hitchhiker.
- Does the CSM have any EVA capability? It's not like picking up a hitchhiker.
No, supposing that each astronaut masses 100 kg including his suit, and the LESS itself masses another 100 kg (which feels low) that means it needs total impulse of 1.7 km/s × 300 kg = 510,000 Ns, which is a middling S motor. Of course theses are not solid fuel motors, and one of the proposals was to have as many as eight ACS thrusters. But still, the available impulse depends mainly on the amount of fuel available. I just don't see enough volume there for an S motor's worth of fuel.Delta V of 1.7km/s without an atmosphere and with only 1/6 of the gravity loss of an Earth launch should make for a fairly small vehicle.
You give me too much credit.I haven't done any calculation myself, but assuming bad_idea has a source and/or calculated it right (and I have no reason to suppose otherwise)...
Found in one of several charts of delta V from surface to orbit of various bodies. Could well be wrong or misinterpreted on my part.Is the 1.7 km/s figure based on the in-orbit specific energy, or the substantially greater figure from the Tsiolkovsky equation?
I hope he's OK.I started this and then had to take my father-in-law to the hospital...
Thanks; we don't know how much longer he has, but if they can't get his heart back into rhythm the prognosis is not good. And they can't shock him for fear of knocking a clot loose, which my daughter tells me is due to turbulence around the valves due to the afib, which is short for something I have to google.I'll crank some numbers a little later. Also...
I hope he's OK.
Enter your email address to join: