Does anyone have an idea of how to stop the cryogenic tanks from boiling off during the interplanetary cruise?
Does anyone have an idea of how to stop the cryogenic tanks from boiling off during the interplanetary cruise? A cryogenic rocket engine performs both the TSI (Trans-Saturn Injection) and Saturn orbit insertion burns, and I'd like to avoid the fuel being gone upon arrival.
Quote from: MarsDude on 02/16/2017 05:18 pmDoes anyone have an idea of how to stop the cryogenic tanks from boiling off during the interplanetary cruise? A cryogenic rocket engine performs both the TSI (Trans-Saturn Injection) and Saturn orbit insertion burns, and I'd like to avoid the fuel being gone upon arrival.ULA says ACES tech should be scalable to any size (and thermodynamically I'd expect it to be rather more effective with larger fuel volumes). Losses would just be from power generation and attitude control (not seen hard numbers on propellant consumption for these, but its supposed to be very small)
I've got power generation figured out: enough RTGs to make a nuclear bomb with their plutonium. Overkill, but it works. As for attitude control: Reaction wheels won't expend any fuel, RCS will.
have three heavily modified Shuttle External Tanks hold the fuel,
Quote from: MarsDude on 02/17/2017 01:19 pm have three heavily modified Shuttle External Tanks hold the fuel, No amount of money is going to make that happen. Also, they are just wrong for the job
Quote from: MarsDude on 02/17/2017 01:03 pmI've got power generation figured out: enough RTGs to make a nuclear bomb with their plutonium. Overkill, but it works. As for attitude control: Reaction wheels won't expend any fuel, RCS will.The Plutonium isotope used in RTGs is useless for nuclear bombs. It won't fission. A GPHS-RTG contains a little under 8 kg of Pu-238, critical mass of Pu-239 is 11 kg. 11 kg of Pu-238 isn't a very large RTG.
Quote from: Hobbes-22 on 02/17/2017 03:35 pmQuote from: MarsDude on 02/17/2017 01:03 pmI've got power generation figured out: enough RTGs to make a nuclear bomb with their plutonium. Overkill, but it works. As for attitude control: Reaction wheels won't expend any fuel, RCS will.The Plutonium isotope used in RTGs is useless for nuclear bombs. It won't fission. A GPHS-RTG contains a little under 8 kg of Pu-238, critical mass of Pu-239 is 11 kg. 11 kg of Pu-238 isn't a very large RTG. I meant if it was Pu-239, it would probably be several megatons.
I don't think that is asking too much. A bit more funding and I can see these missions coming every 10 years or so.
A Europa sub just needs the right fissure--perhaps found by earlier missions. You are right about Webb.ATLAST is a simpler design.
Quote from: Jim on 02/17/2017 01:41 pmQuote from: MarsDude on 02/17/2017 01:19 pm have three heavily modified Shuttle External Tanks hold the fuel, No amount of money is going to make that happen. Also, they are just wrong for the jobYes - there aren't 3x External Tanks left in existence and no manufacturing infrastructure to make more. And how would you launch them, anyway? They had a synergy with the Shuttle that would make them nearly impossible to adapt for anything else, other than a Shuttle Derived Sidemount launcher - and that ship has sailed, so to speak. Possibly you could adapt your idea to tooling used to make smaller diameter rocket stages like the 5 meter Deltas - or just clean-sheet design your ideas to the specs you want or need.