Since Europa Clipper isn't designed yet, it could still be configured to launch on 2 FHs in 2 parts: probe and propulsion. It won't be, but i just wanted to point out how poor a solution SLS is for the cost.
Quote from: RoboGoofers on 04/24/2018 05:32 pmSince Europa Clipper isn't designed yet, it could still be configured to launch on 2 FHs in 2 parts: probe and propulsion. It won't be, but i just wanted to point out how poor a solution SLS is for the cost.No, that does't work. And it is "designed"
not sure what you mean by "work". If two FHs can't lift an assembled probe with enough dV to get to the mission orbit, then use three, or four.
Quote from: RoboGoofers on 04/24/2018 07:02 pmnot sure what you mean by "work". If two FHs can't lift an assembled probe with enough dV to get to the mission orbit, then use three, or four. Even more unworkable. The point of FH is not to get it to LEO but to escape velocity.And more expensive spacecraft.
If the second stage is somewhat lighter, at 4.7t, as has been speculated, then the injected mass could well be 6.1t, the same as SLS (See This europa clipper presentation, page 31.), and exactly what Europa Clipper is designed for, so no spacecraft changes.Sure, that's a completely expendable FH. But it's still much cheaper than SLS, and much more capable than ATLAS.
Scott Manley: I’m also curious as to whether SpaceX would consider stretching Stage 2 if there was a market that made sense.Elon Musk:Under consideration. We’ve already stretched the upper stage once. Easiest part of the rocket to change. Fairing 2, flying soon, also has a slightly larger diameter. Could make fairing much longer if need be & will if BFR takes longer than expected.
Quote from: Jim on 04/24/2018 07:11 pmQuote from: RoboGoofers on 04/24/2018 07:02 pmnot sure what you mean by "work". If two FHs can't lift an assembled probe with enough dV to get to the mission orbit, then use three, or four. Even more unworkable. The point of FH is not to get it to LEO but to escape velocity.And more expensive spacecraft.Jim - Isn't the Europa Clipper a Class A payload since it is a flagship project? Which would mean either SLS or a category 3 certified LV?
Quote from: Brovane on 04/24/2018 08:55 pmQuote from: Jim on 04/24/2018 07:11 pmQuote from: RoboGoofers on 04/24/2018 07:02 pmnot sure what you mean by "work". If two FHs can't lift an assembled probe with enough dV to get to the mission orbit, then use three, or four. Even more unworkable. The point of FH is not to get it to LEO but to escape velocity.And more expensive spacecraft.Jim - Isn't the Europa Clipper a Class A payload since it is a flagship project? Which would mean either SLS or a category 3 certified LV? That is correct. And FH is still a long way from Category 3 certification.Generally, scientific spacecraft, such as Europa Clipper, are appointed to launch vehicles early in their design process. Which is exactly where Europa Clipper is today. The available performance from the launch vehicle is an integrated part of both the mission- and spacecraft design. Therefore, it is important that the final choice of launch vehicle (SLS block 1 vs SLS block 1B) is made as soon as possible.
I do wonder whether craft like the BFS will change this decision making process. Once you have 'huge' lifters with a massive chomper door like the proposed BFS, will it be necessary any longer to make the choice of LV so early?
Quote from: JamesH65 on 04/25/2018 11:47 amI do wonder whether craft like the BFS will change this decision making process. Once you have 'huge' lifters with a massive chomper door like the proposed BFS, will it be necessary any longer to make the choice of LV so early? Flagship mission hardware is designed very early in the process to take maximum advantage of a specific Launch Vehicle. Change the LV and you have to go back to the beginning and start again. That's not going to happen with Europa Clipper. SLS has already been designated as the LV and that is extremely unlikely to change. The only real decision yet to be made is whether the SLS LV will be Block 1 or 1B.
I agree that the EC LV is highly unlikely to change from SLS, but that is largely due to political and less due to technical reasons.
Quote from: woods170 on 04/25/2018 10:07 amQuote from: Brovane on 04/24/2018 08:55 pmQuote from: Jim on 04/24/2018 07:11 pmQuote from: RoboGoofers on 04/24/2018 07:02 pmnot sure what you mean by "work". If two FHs can't lift an assembled probe with enough dV to get to the mission orbit, then use three, or four. Even more unworkable. The point of FH is not to get it to LEO but to escape velocity.And more expensive spacecraft.Jim - Isn't the Europa Clipper a Class A payload since it is a flagship project? Which would mean either SLS or a category 3 certified LV? That is correct. And FH is still a long way from Category 3 certification.Generally, scientific spacecraft, such as Europa Clipper, are appointed to launch vehicles early in their design process. Which is exactly where Europa Clipper is today. The available performance from the launch vehicle is an integrated part of both the mission- and spacecraft design. Therefore, it is important that the final choice of launch vehicle (SLS block 1 vs SLS block 1B) is made as soon as possible.And SLS, which hasn't flown yet, gets a pass.
Don't count your chickens...
So, why do you hate the idea of Clipper flying on SLS?