ESA Laplace, Mission to Jupiter and Europa Options

[MarcF]

I just read in a French astronomical magazine (Ciel et Espace) about the next proposals for future ESA missions (window 2015-2025), and especially about the Laplace mission to Jupiter and Europa.
Some info might be found here: http://jupiter-europa.cesr.fr/
Like Bepi Colombo, the mission should be composed of several spacecrafts: a Jupiter Planetary Orbiter (JPO), a Jupiter Magnetospheric Orbiter (JMO) and a Jupiter Europa Orbiter (JEO), and may be even an Europa lander.
Of course this would be done in collaboration with Nasa and Japan.
I read also about a collaboration with the JUNO spacecraft.
Any chance this will once become a reality ?
Marc.

[vjkane]

I am beginning to doubt that ESA will pick either of the two outer planet missions for their next big mission.

For Jupiter, NASA and ESA have fundamentally different mission architectures. NASA is looking at single craft with a large science payload. (~170kg) ESA has been looking at a split mission in which one craft stays in the outer Jovian system and provides a communications relay while a small orbiter (with a fairly small science payload ~43kg) is placed in orbit around Europa. (The third craft in Laplace, as I understand it, would be a Japanese supplied craft to study the magnetosphere.) (My comments on the Laplace design are based on the ESA Jovian minisat study, which I understand is the basis for Laplace. Please correct me if I'm wrong.)

Neither of the NASA options (a Europa or Ganymede orbiter) has the mass reserve for an additional spacecraft. I also cannot imagine NASA depending on a second craft to handle the communications relay rather than simply building that into their orbiter. Given that, what role could an ESA spacecraft play? At today's exchange rate, 640M euros is roughly $1B, which is the cost of Juno, which is as simple of an orbiter as could be built. However, the purchasing power of the 640M euros in Europe is really more like $640M (unless ESA builds the craft in the United States). So what could ESA add to a Jupiter mission for 2/3 the purchasing power of Juno? Possibly a 3-axis stabilized outer moon flyby/remote Jupiter and Io observer craft. But to fit that into $640M purchasing power, someone else would have to provide the launcher. (Neither NASA option has sufficient mass margin for a second piggy back craft of any size).

For a Titan mission, there are three key pieces of technology development required. The first is aerocapture, which will not be tried out in the next New Millennium mission. Also, presentations on the mission have discussed the need for technology development for the balloon material and operation in a cryogenic environment. Given three pieces of undeveloped technology, I suspect that NASA will pass on Titan for the next Flagship mission. (The Europa mission has had 10-15 years of technology development and has the technology available now that it needs.) Europe could make a major contribution to a multi-craft Titan mission, but again, I don't think NASA will pick it. Instead, I expect NASA to begin funding the technology development for a Titan mission to be selected about 10 years from now.

Unfortunately, $640M in purchasing power just doesn't buy that much for outer planet missions. It would be possible for ESA to build substantial portions of a single Jupiter bound craft, but I don't know if that would provide the visibility that ESA would deserve for that large of an investment.

Now, if I were king and could supply a launch vehicle, I'd love to see ESA fly either a outer moon flyby/remote Jupiter and Io observer or a Ganymede orbiter to compliment a large Europa orbiter. Either would be a killer mission that could be solar powered and would not have extreme radiation problems.

[rlorenz]

........
However, the purchasing power of the 640M euros in Europe is really more like $640M (unless ESA builds the craft in the United States).

I'd be interested in your rationale for that remark.
My sense, having worked in both environments, is that the purchasing power in Europe is (or at least was)
higher than the $$ equivalent - I think typically there are fewer warm bodies doing a given task in Europe (dunno
how the work hours add up, but the number of individuals is smaller). ESA does have issues like juste retour
which will surely decrease the fiscal efficiency of a project, so you might well be right, but I am curious why
you say so.

It is worth noting that the ESA mission cost reflects the platform only - the not insignificant costs of payloads
(and it is perhaps a semantic distinction as to whether you consider sub-vehicles like a French balloon as a
payload or a separate spacecraft) are borne separately by the member states, so perhaps 800 or more Meuro
might get spent in total in Europe on a '640 M' ESA project

....
For a Titan mission, there are three key pieces of technology development required. The first is aerocapture, which will not be tried out in the next New Millennium mission.

All the technology developments in all the NASA Flagship studies were rolled into their costs, and schedules are
laid out accordingly so in some ways that shouldnt be a discriminator (at least if you believe the radiation issue is
solved) so I'd like to think therefore that scientific merit will be the deciding factor. You can also think of the
technology developments as assets rather than liens - announce you are spending $$$/EURO on a Titan Flagship and
soon there are test balloons floating around, robot arms digging in tents drenched with liquid nitrogen, cool stuff
like that - tangible stuff people can relate to and see their money being spent. Drop all your $$ on an orbiter and,
well, you get an orbiter.

Editorially, I think without exception everyone I have spoken to sees an aerocapture demo as technically
unnecessary - more of a 'give warm fuzzy feeling to program manager' exercise. (Recall that Apollo was
qualified to do skip entry, the Russian Zond probes actually did it ; I think Constellation will be doing it; MSL
has guided entry which is functionally similar.... the demo requirement could be removed with the stroke of a pen)

Ralph