Jupiter flagship selected Options

[EccentricAnomaly]

**POOF**

[EccentricAnomaly]

**POOF**

[tedstryk]

Even with gunk, liquid would be considerably easier to sample than rock or regolith. This is a much easier challenge than the sampling challenges faced by Viking or Surveyor or Phoenix. In exploration there is always going to be some sort of unknown.... and you won't know 100% what a surface is like until you go there. By the 2020's (when a Titan mission would be launched) we're going to know everything about the surface that Cassini-Huygens can tell us and we won't know any more until we go there.

The complexities of getting to Titan, landing there, and getting data back are not nearly so simple as you suggest. "Much easier" than a Mars mission? Ha!

At any rate, I will repeat that saying the Europa mission is more technically ready is not an attempt to mock the Titan mission. To suggest the Titan mission is easier than a Mars mission is beyond ridiculous and not worth discussing.

[volcanopele]

If anything I thought the press release didn't go far enough to explain the reasoning behind decision to go with Europa first, then Titan later. But to say that it didn't make it clear that both are needed, or that it is putting an albatross on the Titan mission, I don't think is fair. I think the fairer thing to say is that NASA and ESA acknowledged that there has been more technological development in preparation for a Europa mission over the last decade, particularly in rad-hard electronics, than the Titan mission, where Cassini follow-ons have only been considered in earnest for the last two or three years.

It is clear from the press release that this isn't an end for development of a Titan mission. Like the Europa mission, it could use more marinating, in other words, now that we have an idea of what a Titan mission might look like, we can work over the next decade to get those technologies up to the level where Europa is now, so that when the next Flagship mission is chosen, Titan will be ready-for-primetime. The press release makes this clear when it mentions that Titan mission will continue to be developed in conjunction with the upcoming decadal survey.

[ngunn]

I agree. The press release seems to leave Titan quite clearly next in line, and not neccessarily a decade behind. It even proclaims "everybody wins". I don't think they'd have said that if Titan was to be very much deferred, or in doubt altogether.

Titan easier than Mars? Well I have to say I agree with that too. I think that's one of the new insights we have, thanks to Ralph Lorenz and friends. It's easy to fly, and it's easy to splash down and sail. Most importantly, it's easy to slow down when you arrive there at high speed through the vacuum of space. That lovely deep, cool and chemically benign air and gentle gravity do the whole job. There is nowhere else so welcoming or with so much to offer the (robotic) explorer.

[imipak]

Even with gunk, liquid would be considerably easier to sample than rock or regolith.

How so?

(edit) As Centsworth said: "Everyone here wants to see both missions fly", and no-one, I think, would disagree with EccentricAnomaly that "We need to celebrate the Europa selection and back a subsequent Titan mission at the same time. "

[ngunn]

If it won't fit in the tube just ask it to walk up the ladder.

[EccentricAnomaly]

**POOF**

[ngunn]

I was certainly not mocking anybody there, nor weighing in with a particular point of view. My post was entirely and solely whimsical and surreal. I do that occasionally - maybe it's not such a good idea. My sincere apologies for any annoyance caused.

[imipak]

Well now, and I took it to mean I'd missed some well-known reason liquid sampling's harder than solids. ("Is there some exotic surface-tension or electrostatic effect I haven't heard about which makes sample "walk" up a "ladder"? I pondered. I was about to hit start googling... I suspect we're all in violent agreement here, actually. ( Group hug? [1] )

My last comment on this is that although Titan isn't capital-aitch Hard, it's something we've only done once, compared to, what, almost a dozen attempted Mars landings. As is clear from Mike's awesome heptane experiment, the surface properties are not well understood right now - certainly nothing like as well as Mars, and we saw with Phoenix that there are unknown unknowns there, too. The distance to Titan means there'll always be a substantial lead-time between receiving data from one mission, doing our best to grok it, and designing, building and flying the next. NASA's decision to fly Europa first whilst continuing work on Titan strikes me as a clever (and presumably difficult) cutting of the Gordian knot.

[1] wildly O/T sidenote: an American friend left my employer recently; after seeing him give two successive people massive bear hugs as he left, I couldn't resist taking a step backwards and extend my hand for a polite shake... "Jolly good luck, old chap!" :>

[nprev]

Re remote examination of cryogenic-temp liquids: After some thought, this seems like a non-trivial problem. Gross compositional measurements via a GCMS seem quite feasible, but what of the more volatile fractions? (Thinking complex organics of unfamiliar structure, here). Detailed chemical analysis seems necessary, and I frankly don't even know where to begin there.

All this stuff, whatever it might be, is at thermal equilibrium with its environment. I may be wrong here, but to my knowledge we really don't have much experience designing complex electronics & associated small-scale mechanical systems that work in hypercold environments like Titan for prolonged periods of time--and they'd HAVE to in order to avoid destroying a liquid sample before it could be analyzed.

Point being, this particular aspect is just one small but crucial component of the overall technological readiness needed to really tackle Titan at a Flagship scale. It's wise to remember as well that future missions to Saturn need to be very capable indeed scientifically if for no other reason than that it's a real ordeal just to get there. Launch opportunities to Jupiter are more frequent, and the transit time is much less than that to Saturn. Therefore (IMHO), EJSM seems like the right mission at this time.

[djellison]

I'm going to draw a line under the 'technical readiness' debate. People can read the various proposals and figure it out for themselves.

[Juramike]

I'm going to assume you didn't see the message above whilst adding your reply. Post culled - Admin

[Mariner9]

I'm a bit concerned about this statement by Louis Friedman I read over on the Planetary Society blog:

While the previous FY 09 budget request included new initiatives including a Mars Sample Return mission, an Outer Planets Flagship mission, and a Joint Dark Energy mission, among others, that could not realistically be accommodated within the FY 09 budget proposal, the FY 10 budget plan for space science no longer includes these or other major new initiatives. For example, NASA selected the Europa Jupiter System target as the focus of an Outer Planets Flagship mission, but elected to proceed with technology development, further definition, and discussions on a potential partnership with the European Space Agency (ESA) on a potential future mission. The FY 10 budget plan for planetary sciences does not include a Mars Sample Return mission. NASA officials have indicated their interest in working more closely with ESA on potential Mars missions for the 2016 and 2018 launch opportunities.

I had always assumed that the Mars Sample Return would return to the back burner, but this part really worries me:

- the FY 10 budget plan for space science no longer includes these or other major new initiatives.

I realize that initially the mission is mostly design and study, with no metal being cut for several years, but does his statement mean that mean that the Europa flagship has been downgraded, and s not going to be funded as a real mission, but just as a technology development with hopes of becoming a real mission later?

[vjkane]

I realize that initially the mission is mostly design and study, with no metal being cut for several years, but does his statement mean that mean that the Europa flagship has been downgraded, and s not going to be funded as a real mission, but just as a technology development with hopes of becoming a real mission later?

If the Flagship launches in 2020, real money will be needed starting in 2015 or 2016. The current timing for the mission is based on trying to recover from the MSL slip plus aligning with ESA's budgeting for their portion (assuming they select this mission as their next large science mission).

I foresee two big problems. First, if NASA's science budget stays roughly flat (with increases, hopefully, for inflation), then NASA will either have to forgo its aggressive Mars program for a few years or forgo New Frontiers and Discovery missions for a few years. I just don't see anywhere to stuff a $3B mission in the current funding profile without giving something up. This, I predict will be the biggest fight of the upcoming decadal survey (with the fight over a series of small or a sample return for the Mars program being almost as big of a fight).

The second problem that I foresee is that the Titan mission will be going through the same kinds of mission definition in the next few years that the Europa mission did over the last decade. That could bring the Titan mission to a high state of readiness. If so, I see the selection of the next Flagship target being revisited, again, which could delay the whole thing into the 2020s.

I think that the portfolio of missions put forth last year under Stern was a tad bit optimistic both in terms of funding that would be made available and the chances that no major missions would have cost overruns. (Alan, if you think I'm wrong, please let us know.) Hence, there is likely to be a lot of missions pushed out.