Quote from: redliox on 10/25/2017 11:54 pmI do however see you point about doing a "rush job" on a mission as important as Europa Clipper. I would think being given full funding between now and its earliest tentative launch date of 2022 could get things done in the ~5 year space, emphasis on "if" being key. My concerns are less with the probe itself and more with SLS, especially since it will be the first mission to ride a EUS (and I imagine JPL is less-than-happy about playing Guinea Pig).In your professional opinion Blackstar, how much time would be best to spend maturing a flagship mission once it's into Phase B onward?EC has some issues that they are working through. At least one of them could be a major problem, or it could go away suddenly (because it's based upon a model, not actual data, and the model is currently showing something rather bad). One of the things that has been plaguing them for a while now has been that they committed to a set of instruments rather early, and now they're trying to fit them to a spacecraft. Usually that is more of an iterative process, but because they had the money early, they settled on the instruments early, and it's proving hard to design a spacecraft that can accommodate all of them.The decision point for SLS happens in 2018. That's when they have to have a vehicle approved.
I do however see you point about doing a "rush job" on a mission as important as Europa Clipper. I would think being given full funding between now and its earliest tentative launch date of 2022 could get things done in the ~5 year space, emphasis on "if" being key. My concerns are less with the probe itself and more with SLS, especially since it will be the first mission to ride a EUS (and I imagine JPL is less-than-happy about playing Guinea Pig).In your professional opinion Blackstar, how much time would be best to spend maturing a flagship mission once it's into Phase B onward?
The lander is a different issue entirely. We'll see what happens there (cue mysterious, slightly ominous music...)
Mass has been another problem because the project wants to keep non-SLS launch options available. If the project goes with SLS, I believe that the mass problems go away, but we are likely looking at a mid-2020s launch based on that vehicle's progress or lack thereof.
Quote from: vjkane on 10/26/2017 05:10 am........Thus far, it'll look like 'Clipper could launch somewhere between '22 and '25 with emphasis on the later date?
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If the 'Clipper is launched beyond 2023. Then there will be more launch vehicle options available if the various development programs have flying hardware in the next few years. IMO no decision regarding the launch vehicle selection for the 'Clipper should be make until after the next US Presidential election. Funding & launcher availability should be more clear.
Quote from: Zed_Noir on 10/27/2017 03:51 amIf the 'Clipper is launched beyond 2023. Then there will be more launch vehicle options available if the various development programs have flying hardware in the next few years. IMO no decision regarding the launch vehicle selection for the 'Clipper should be make until after the next US Presidential election. Funding & launcher availability should be more clear.I believe that the mission has to settle on a launch vehicle soon so they can design the spacecraft to the specific requirements of the vehicle and resulting flight plan (for example, does the spacecraft have to be designed for the heat environment of a Venus flyby?).
From what has been publicly said, a key issue has been power. In many missions, the key power driver is the communications system. Ralph Lorenz published a paper showing the power needed to push the data back to Earth is the largest consumer of power on many planetary spacecraft.
Subduction--the sliding of one tectonic plate beneath another--is possible on the ice shell of Jupiter's moon Europa, a new study shows. The process could supply chemical food for life to a subsurface ocean.
Rep. Culberson’s Seat in Jeopardy?One of the Republican seats that may be in jeopardy according to the Times belongs to Rep. John Culberson, chairman of the House Appropriations Subcommittee on Commerce-Justice-Science (CJS) that funds NASA and NOAA... Using the power of his chairmanship, he has compelled NASA to build and launch a probe to Jupiter’s moon Europa because he is convinced life exists in the ocean that some scientists believe exists under its icy shell...
Might be more difficult than I thought. F9H fairing is 43 feet tall. Both Centaur and DCSS would both occupy most of that length leaving little room for spacecraft. Extended fairing or placing the 3rd cryo stage between stage 2 and fairing would probably cause more engineering work than SpaceX cares to expend on the F9 at this point.
In the afterglow of yesterday's F9H flight I think it is worth spending some time on launch options again. From a taxpayer's standpoint I am not sure I want to keep SLS going just for this mission. I have a much higher degree of confidence that BFR will obviate the rationale by 2030. We have waited half a century for sustainable interplanetary transport I have no problem cancelling SLS and waiting at most an extra 5 years to get into cis lunar space.Realize F9H stage 2 not optimized for beyond GTO but can F9H do this mission with only Earth flybys?