publiusr - 4/5/2006 1:22 PMWhat is more, the current Cassini Titan probe needed both a good upper stage and gravity assist.If you want greater outer planet probes, you need a bigger rocket. It would probably take CaLV to do JIMO right, sample return missions from Mars (with margin) and Europa landers. We got away with the Delta II to Mars because that planet did us a favor by being nearby and had an atmosphere to aerobrake and pop a chute in.You won't do that with Europa. No cheating. You will have to dump speed and burn your way to the surface. By the time you are done you melt and deploy a cryobot about the same size as Spirit or Opp. That looks for smokers.So you need real heavy lift to orbit Kuiper objects, to land on Jovian moons, or to return Martian samples. Either that or these Rube Goldberg schemes people come up with who fall all over themselves to keep from admitting a need for greater lift.
yinzer - 4/5/2006 2:08 PMEuropa has no atmosphere. Maybe a couple of microbars of atomic oxygen or something, but nothing you can aerobrake against. Aerocapture against Jupiter is also quite hard, because it's so massive that orbital speed at the top of it's atmosphere is very, very high. The radiation environment at and inside Io's orbit is also pretty nasty.
publiusr - 18/5/2006 2:53 PMI don't agree with that at all. Casseni isn't exactly cheap--and EELVs are too weak for JIMO and Europa lander missions. Look, we have funded 100 STS missions, each of which had lift-off thrust similar in power to Saturn V, and we have stayed in LEO. With CaLV subsituted for STS, with the same flight rate and the same or less costs as STS (no orbiter costs) the Solar System will open up to us in a way never before conceived. Naysaying only hobbles this.BTW the OTV masses out to nearly 40 metric tons. What are you going to launch this with, besides CaLV?You want to do EELV assembly, ISS style? Yeah--that style assembly really got Space Station finished in a hurry, didn't it?I'll take single shot Skylab segments myself thank you. That was cheaper than ISS. Heavy Lift saves money, in launches, in assembly, in pad times, in engines, and in upper stages.
Spacely - 4/5/2006 2:40 PMUsing expensive CaLV launches to lift aleady expensive (I'm talking 2-5 billion dollars here) sample return and outer planet orbiting missions seems like a catastrophic misuse of NASA funds, as such missions would essentially kill Space Science. We'd get, say, a Neptune Orbiter with Probes, and... well, that'd be it. For a decade.Why not invest upfront in the oft-tabled OTV instead of using precious CaLVs and hundreds of millions per launch? http://www.astronautix.com/craft/otv.htm
I also got a document call Centaur G-Prime Technical Description. Unfortunately, it is spiral bound.