Is Europa really the "highest priority" of the community?, Cleave said it was at LPSC? Options

[Guest_AlexBlackwell_*]

Such a mission would never get done this decade, so it's not incompatible with their citing the decadal survey.

Well, one should note that the "Europa Geophysical Explorer" mission recommended in the Decadal Survey wouldn't have flown in this decade, either. Neither would have JIMO.

[elakdawalla]

Well, one should note that the "Europa Geophysical Explorer" mission recommended in the Decadal Survey wouldn't have flown in this decade, either. Neither would have JIMO.

True. I guess I meant "started," but the point is well made that the 2010s will be a decade without a flagship mission.

--Emily

[Guest_AlexBlackwell_*]

True. I guess I meant "started," but the point is well made that the 2010s will be a decade without a flagship mission.

No argument there, though I continue to believe that international cooperation (despite the digs about NASA being an unreliable partner) is the enabler for Flagship-class missions.

As for the Decadal Survey, I wasn't trying to be argumentative (Who? Me? ). It's just that I think the "community" should be careful in their recommendations. After all, the whole point of the survey was to present a united, consolidated view of what planetary scientists are recommending.

[Guest_BruceMoomaw_*]

If Europa were the "highest priority" of the PS community as a whole, then one might wonder why we were spending all this money on Mars. I could easily imagine that Europa is the highest priority of the outer planets community, but frankly I was surprised when Europa Orbiter appeared in the '07 budget (presumably the result of some serious lobbying on someone's part.) It was pretty obvious to me then that there would be no money for it, especially in the aftermath of JPL running the old EO project into the ground with cost overruns and engineering upscopes. (And JIMO is best forgotten.)

First, as I said, Mars is in a category all by itself -- the NASA brass recognize it as a gold mine for them funding-wise, and so missions for it are considered super-high priority by NASA regardless of what the actual planetary-science community thinks. (Jeff Bell tells me that Mars scientists, who benefit from this, are bitterly known by other planetary scientists as the "Mars Mafia".)

Second, I found out at the Europa Focus Group meeting who got Europa Orbiter into the 07 budget. As is so often the case, this was due to idiosyncratic personal enthusiasm by one Congressman --- John Culbertson of Texas, who showed up at the meeting to excoriate the removal of EO again and to swear undying enmity against any further attempts to delay it. He is an otherwise standard-model right-wing Republican who happens to be an amateur astronomer and geologist, with the result that he is apoplectic about the cuts in space science but isn't (yet) willing to buck the President by trying to pull money out of Shuttle/Station. (He said that he personally takes a dim view of it , but that NASA is stubborn in refusing to cut its funding.) As a result, he proposes to refund space science by increasing NASA's funding as a whole -- which I imagine ain't gonna fly, but we'll see.

Anyway, he not only got EO into the initial '07 budget, but was responsible for restoring $10 million of the cut funding for SIM. He also said that he was largely responsible for the funding for Prometheus, and that when he got it funded he had Europa in mind as a goal for it. (I hope someone gets a chance to tell him about the unwisdom of using NEP to study Europa, or he may unintentionally veer us off onto an unwise detour.) So there is at least one genuine, honest-to-God Europa enthusiast in Congress -- which is more than a lot of space scientists have.

[elakdawalla]

As for the Decadal Survey, I wasn't trying to be argumentative (Who? Me? ). It's just that I think the "community" should be careful in their recommendations. After all, the whole point of the survey was to present a united, consolidated view of what planetary scientists are recommending.

Yeah, and they realize that. There is a lunch meeting tomorrow (Thursday) of people interested in the future of outer planets exploration, and I'll be very interested to see who shows up and what they have to say to each other. Also, the next OPAG meeting is in early May in Pasadena. I expect there will be formal discussion of this Titan question then, if not before.

--Emily

[Guest_BruceMoomaw_*]

Regarding Titan exploration: the PS community currently harbors some hope that a Titan surface-analysis aerobot WITHOUT an accompanying orbiter might be flyable within the New Frontiers budget (e.g., the windblown-balloon version of Titan Organics Explorer). I'll believe it when I see it, though.

Meanwhile, Ralph Lorenz's study group has just concluded that a Titan orbiter with some small additional package (a stationary lander or a fixed-buoyancy balloon) might instead be the best next step. See the last page of http://www.lpi.usra.edu/opag/oct_05_meetin...an_work_grp.pdf . See also pg. 16-30 of http://www.lpi.usra.edu/opag/jun_05_meetin...s/opagtitan.pdf , and the orbiter part of the proposal in http://www.lpi.usra.edu/opag/oct_05_meetin...ngley_titan.pdf .

Such a relatively small stationary lander might very much be worth adding if Cassini can find a location on Titan that is likely to be the result of water cryovolcanism, so that the lander could look for complex water-formed organics. (Or maybe even the remnants of Titanian microbes vomited up from its subsurface water-ocean -- yes, they are thinking about just that in connection with Titan Organics Explorer, and thus one thing it's supposed to do is check any organics it finds for chirality.) That is, the lander would carry the relatively stripped-down science payload planned for TOE, plus maybe a seismometer. (I still think the Huygens team missed a major opportunity by not replacing most of those silly British surface instruments with a short heated core tube hooked up to the GCMS.)

As for a small nonlanding balloon: it might be worth doing too, and not just for weather studies. Titan is one world where cameras on a balloon could do surface observations which CANNOT be done by a camera from orbit, no matter how high-powered -- and Titan's surface is clearly so complex that something of the sort will be needed to understand the place. I also wonder whether such a balloon might carry a subsurface radar sounder -- which is starting to look like something else we will badly need to understand Titan, and which (according to Lorenz) is hard to put on an orbiter because of the difficulty in getting an orbiter down to a low enough altitude for it to work right.

That same extraordinary atmospheric scale height on Titan, though, is indirectly the cause of the one reason why it might be worthwhile flying to Titan before Europa: namely, that (as John Rehling points out) it's a hell of a lot easier place to either land on or orbit. Saturn lacks Jupiter's savage radiation environment; and Titan happens to be the easiest world in the Solar System at which to aerocapture an orbiter -- which would vastly reduce the craft's weight, and which (we were told at the November COMPLEX meeting) we will be completely ready to do for any world in the Solar System once the New Millennium program runs the one proposed Earth-orbital test of the procedure. In short, it may, repeat MAY, be possible to fly a Titan mission which would be fairly close in scientific productivity to Europa Orbiter, but much cheaper -- at which point it WOULD become competitive with EO.

The overall lesson, though, is that it is still way too early to even begin to decide what kind of mission to fly at Titan until Cassini has finished giving the place a far more thorough once-over -- which will take years. And that, in turn, might be a valid reason to delay Europa Orbiter -- if Cassini's later studies of Titan do indicate that it can be explored in a highly scientifically productive way for much lower cost than Europa Orbiter, with or without study of Enceladus thrown in as an addition.

[Stephen]

One reason Bob wanted to stand up and say that yesterday is because he (and the rest of the Europa community) were alarmed by the possibility that Jonathan Lunine's provocative suggestions of Titan as being the one target he would explore if forced to choose one would be seen as "mixed messages" coming out of the outer planets community. Lunine's point is debatable, but as far as mission planning is concerned it's not really a relevant one. Planning out future missions requires not only looking at what questions scientists desire to answer but also the maturity of the field and the technological readiness to start a new mission. With Cassini still at Saturn it's not time yet to start a Titan mission now -- one would guess it would be a top candidate for the single large mission of the next decade, after Europa.

Doesn't look like NASA's too interested in considering large missions at all right now though.

But isn't that going to be a looming problem if NASA keeps on postponing a Europa mission?

If NASA waits around long enough it may well be the next decade before a Europa orbiter gets back onto its budgetary agenda. It is, after all, already 2006. Without an infusion of extra funds NASA's budgetary situation seems unlikely to change before 2010 at the earliest when the shuttles retire, and maybe not even then if the VSE swallows the lion's share of the newly freed-up money. If the Europa cheer squad are still waiting around for NASA's OK when Cassini ends they are going to find themselves competing for NASA's attention and money with the Titan cheer squad who will doubtless by then have plans for a followup mission or missions of their own. If NASA cannot afford missions to both places at the same time, then it will be forced to choose between one or the other. If that happens somebody is going to have to wait.

One might expect that to be the Titan folks. The problem for the Europa cheer squad, though, is that they are really after not one but at least two missions: a Europa orbiter followed by a Europa lander-cum-borer-cum-diver. Since much of the point of the first is to decide where (or even whether) to send the second that is going to make the orbiter seem merely an (expensive) precursor to the more sexy main event. Given much of the rationale for going to either place is to find life or its precursors, a mission to Titan may well look like getting the answers (or some of them at any rate) everybody wants sooner, more easily, and in a less expensive fashion than going to Europa.

======
Stephen

[Guest_vjkane2000_*]

The overall lesson, though, is that it is still way too early to even begin to decide what kind of mission to fly at Titan until Cassini has finished giving the place a far more thorough once-over -- which will take years. And that, in turn, might be a valid reason to delay Europa Orbiter -- if Cassini's later studies of Titan do indicate that it can be explored in a highly scientifically productive way for much lower cost than Europa Orbiter, with or without study of Enceladus thrown in as an addition.

I suspect that it may be time for looking at much more creative options for Europa missions. The Europeans have studied an all solar-powered, two spacecraft mission. One report from several years ago on a possible NASA Europa orbiter stated that a fall back mission would be an intense set of flybys of Europa that could conduct radar soundings at each flyby (with the limitation that the latitudinal coverage would be primarily near the equator). Perhaps something like this could be combined with an internationally contributed lander/penetrator.

[gpurcell]

If you're in your 20's - you have Cassini
If you're in your 30's - you had Galileo
If you're in your 40's - you had Voyager
If you're in your 50's - you had Viking

yes yes - lots of overlap and doesnt really sit in those catagories properly, it's a metaphor more than a real survey of the past - but there's nothing for our teenagers - where is their Voyager? Has there been a point in the last 40 years when the next really big mission wasnt at least in the planning stages?

Doug

Well, I'm in my 30s and what I mainly remember is the long, long gap with NOTHING in the 1980s.

[ljk4-1]

Well, I'm in my 30s and what I mainly remember is the long, long gap with NOTHING in the 1980s.

There were actually quite a few planetary missions in the 1980s,
especially if you count non-USA countries, but yes, no new planetary
missions by the USA were launched between the Pioneer Venus
probes in 1978 and Galileo in 1989.

And let's not forget Reagan's financial guy who tried to shut down
Voyager 2 in 1981 after its Saturn mission to save a few bucks.

[elakdawalla]

Well, I'm in my 30s and what I mainly remember is the long, long gap with NOTHING in the 1980s.

...which is exactly why The Planetary Society was formed in 1980. Things are looking awfully familiar to people who have been around since we got started.

--Emily

[remcook]

That's pretty depressing, especially if you want to find a job in planetary sciences :*-(

[Guest_AlexBlackwell_*]

There were actually quite a few planetary missions in the 1980s,
especially if you count non-USA countries, but yes, no new planetary
missions by the USA were launched between the Pioneer Venus
probes in 1978 and Galileo in 1989.

Not to be pedantic but Magellan launched five months before Galileo. It's true, though, that the latter was started first.

[tedstryk]

If you're in your 20's - you have Cassini
If you're in your 30's - you had Galileo
If you're in your 40's - you had Voyager
If you're in your 50's - you had Viking

yes yes - lots of overlap and doesnt really sit in those catagories properly, it's a metaphor more than a real survey of the past - but there's nothing for our teenagers - where is their Voyager? Has there been a point in the last 40 years when the next really big mission wasnt at least in the planning stages?

Doug

If you're in your 60's - you had Apollo.

Well, there has been continuity....in outer solar system exploration, the pioneers started, and the Voyagers overlapped the end of their solar system mission. Then Galileo was launched just after Voyager 2 flew by Neptune, and Cassini had flown by Jupiter and was on its way to Saturn by the end of its mission. Now we have New Horizons with Juno on the way. What disturbs me is, ignoring the technological advances that skew the comparison, Juno and New Horizons seem more on the scale of Pioneer. Now, if we look at solar system exploration in general, MSL might fill the roll of a big mission.


I think it is really a mixed bag. There certainly is the lack of big missions coming down the pipe. But we are in much better shape than the 1980s, which, had Voyager and PVO not outlived their waranties, would have been limited to ICE, a "comandeered" planetary mission, the Halley flotilla, some Veneras, and Phobos-2.

A major problem, after New Horizons, is that our targets are more problematic. The public can follow the idea of missions to the moon, Mars, Venus, Pluto, etc. But Titan, Europa, Ceres, Vesta, Io, and the Kuiper Belt? Most people have never even heard of the these places, including Congress. We are eating the fruit of decades of bad science education.

[djellison]

long gap with NOTHING in the 1980s.

Galileo WOULD have launched in '86 were it not for the Challenger accident though.

Doug