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ESA Laplace, Mission to Jupiter and Europa
Paolo
post Nov 4 2007, 07:45 PM
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QUOTE (gndonald @ Nov 3 2007, 03:34 PM) *
[off topic]

NASA was looking at 'Solar Electric' (Ion Drive) missions from the early 60's to about the early/mid 70's, they even considered using them to get to Jupiter and to perform Ulysses style missions above the ecliptic.

See Study of a common solar-electric-propulsion upper stage for high-energy unmanned missions. Volume 2 - Technical Final report(14mb) for all the details of the planned 'mission bus'.

[/off topic]



The original European proposal for the out-of-the-ecliptic mission was also to be electric engine powered. This image is taken from a ESRO document of 1972


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I'm one of the most durable and fervent advocates of space exploration, but my take is that we could do it robotically at far less cost and far greater quantity and quality of results.

James Van Allen
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rlorenz
post Nov 4 2007, 10:07 PM
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QUOTE (vjkane @ Nov 4 2007, 12:00 PM) *
........
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
QUOTE
....
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
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gndonald
post Nov 5 2007, 01:34 AM
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QUOTE (Paolo @ Nov 5 2007, 04:45 AM) *
The original European proposal for the out-of-the-ecliptic mission was also to be electric engine powered. This image is taken from a ESRO document of 1972


It does not look dissimilar to the 'Solar Electric Mission Bus' that NASA/TRW were looking at around the same time, but then the engineering problems were identical, though NASA was looking at everything from close (0.1au) solar orbit missions to Jupiter flybys.

It's sobering to think that out of all of them only the comet rendezvous (Deep Space 1) and the asteroid rendezvous (Dawn) have been attempted, with the Dawn mission being closest to what was originally envisaged over 30 years ago.
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vjkane
post Nov 5 2007, 04:23 AM
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QUOTE (rlorenz @ Nov 4 2007, 10:07 PM) *
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...

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


Ralph raises some good points, especially that ESA's mission costs do not include the instrument development, which can run into very significant figures. I'd forgotten that.

As for my concerns about the purchasing power of the Euro versus the dollar, here is my thinking. It was not long ago that the two currencies were trading nearly 1 to 1 (early 2003, if I recall, and the two have bounced between that and the current ~1:1.4 since). Ideally, currency exchange rates would reflect only the relative purchasing power of the two currencies. While that is a factor, supply (there are too many dollars floating around the world) and demand (as American interest rates fall, so does demand for dollars) are responsible for a lot of the short term oscillation. So when the current Euro target expenditure is translated to dollars and today's exchange rates, it appears that ESA's next mission would be equivalent to approximately a New Frontier's class mission, especially when you consider that the instrument costs aren't included. If, however, you assume that the real purchasing power of each currency is approximately equal within its own geography, then the purchasing power of the Euro would be less than the current exchange rate would indicate. Clearly, this is a complicated subject that reflects many factors. NASA, I've read, calculates its own rate of inflation separately from the CPI because NASA buys largely within the States and what it buys often is custom designed and manufactured by well paid workers. I suspect that somewhere there is a group that tracks relative costs of aerospace procurement around the world, and that would be the definitive word on this subject.

I think a multi-craft mission to Titan would be fantastic. When I put on my ex-high tech manager hat (these days I'm getting a PhD in environmental remote sensing), technology development was always the biggest risk to a project's costs and schedule. With Alan Stern's focus on managing within fixed budgets, I think that the technology development of the Titan mission puts it at a competitive disadvantage. On the other hand, a significant contribution of foreign investment into the Titan mission might swing the selection.

Clearly, I don't have any inside track on what will be decided, but I am very interested in hearing the opinion of others who have more direct experience as Ralph does.


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rlorenz
post Nov 5 2007, 01:14 PM
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QUOTE (vjkane @ Nov 4 2007, 11:23 PM) *
As for my concerns about the purchasing power of the Euro versus the dollar, here is my thinking. It was not long ago that the two currencies were trading nearly 1 to 1 (early 2003, if I recall, and the two have bounced between that and the current ~1:1.4 since). Ideally, currency exchange rates would reflect only the relative purchasing power of the two currencies. While that is a factor, supply (there are too many dollars floating around the world) and demand (as American interest rates fall, so does demand for dollars) are responsible for a lot of the short term oscillation. So when the current Euro target expenditure is translated to dollars and today's exchange rates, it appears that ESA's next mission would be equivalent to approximately a New Frontier's class mission, especially when you consider that the instrument costs aren't included. If, however, you assume that the real purchasing power of each currency is approximately equal within its own geography, then the purchasing power of the Euro would be less than the current exchange rate would indicate. Clearly, this is a complicated subject that reflects many factors. NASA, I've read, calculates its own rate of inflation separately from the CPI because NASA buys largely within the States and what it buys often is custom designed and manufactured by well paid workers. I suspect that somewhere there is a group that tracks relative costs of aerospace procurement around the world


Yeah - I guess we need something like the Economist's Big Mac Index for spacecraft. This index
factors purchasing power into exchange rates
http://www.economist.com/markets/Bigmac/Index.cfm

e.g. in Feb of this year, a Big Mac was $3.41, but averaged Eur 3.06 (=$4.12), so for Big Macs at least the situation
is closer to vjkane's outlook of Euro worth less than a dollar. But as NASA's own avoidance of the CPI
suggests, spacecraft costs have less to do with what burger-flippers and beef farmers are paid than on the
number and seniority of engineers writing code and laying out circuits :my contention was based more on issues
like the heavy regulatory burden on NASA (e.g. I think New Horizons had to pay for special cameras at the cape
to be able to track the RTGs if they fell off in a launch explosion...), the pool of young technical talent (lots
of people from some countries have to do some kind of 'military service', which in many cases can simply
be some technologically-related work that may not get charged to a project,plus I think more students are
dragged in to do work in Europe that better-paid engineers might be required to do in the USA). On the other
hand, people work fewer hours in Europe, so there are a lot of factors.

Yeah, definitely need a Beagle Index or something. If anyone out there can contribute hard numbers to this
discussion it would be most appreciated.
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rlorenz
post Nov 5 2007, 01:21 PM
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QUOTE (vjkane @ Nov 4 2007, 11:23 PM) *
I think a multi-craft mission to Titan would be fantastic. When I put on my ex-high tech manager hat (these days I'm getting a PhD in environmental remote sensing), technology development was always the biggest risk to a project's costs and schedule. With Alan Stern's focus on managing within fixed budgets, I think that the technology development of the Titan mission puts it at a competitive disadvantage. On the other hand, a significant contribution of foreign investment into the Titan mission might swing the selection.


Again, like the technology developments being seen as visible and exciting use of funds, the multiple-element
nature of a Titan mission is in some sense a risk reduction
(one can at least track the balloon from the ground a la Huygens VLBI/Doppler, and some
modest DTE capability can be easily implemented on a lander, and without too much difficulty on a balloon)

So, indeed there are more bits to go wrong (i.e probability of science return = 100% is less),
but by ensuring at least some science can be returned from the in-situ platforms even if the
orbiter fails, then the probability of science return = 0% is far lower than in a pure orbiter case.

It all depends what risk/science profile you want. Titan at least has lots of options to choose from.
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vjkane
post Nov 5 2007, 04:09 PM
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A modest proposal:

The concurrent consideration of the next Flagship, ESA major mission, and New Frontiers does open up one possibility.

NASA could totally fund either a Jovian or Titan mission as its next Flagship mission. Then the ESA funding and New Frontiers funding together could fund a more modest mission to which ever body didn't get selected for the Flagship mission.

So, it's theoretically possible we could get missions to both bodies in the next decade.


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ngunn
post Nov 5 2007, 05:00 PM
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That's exactly the scenario I've been quietly hoping for. Both need doing so let's lobby for both. I've never gone along with the 'better not push for B in case A suffers' school of thought.
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djellison
post Nov 5 2007, 05:40 PM
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Which of the two (Jovian or Saturnian) splits up the simplest (i.e. Cassini+Huygens level split). Would one 'half' be a SEP module perhaps, in trade for a few instrument slots.

Doug
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vjkane
post Nov 5 2007, 06:27 PM
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full inline quote removed - Doug

If I remember the $1B box studies (I'm not at home where I have the presentations), a Titan balloon mission without a relay (i.e., the balloon gondola has its own antenna) was around $1.5B. My guess is that the balloon + gondola portion (and maybe the entry shell) would be about $6-800M, which could be ESA contribution. (And this would take advantage of the French balloon expertise.) NASA could provide the launch and carrier craft plus mission operations and tracking.

For Jupiter, I think that $1.5B would buy a Galilean satellite tour craft (flybys only). Here, splitting costs seems harder. One possibility is that the two craft mini-sat idea proposed by ESA (and is the core of Laplace, I believe) might work. But I have my doubts.


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power
post Nov 20 2007, 02:31 PM
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QUOTE (ngunn @ Nov 1 2007, 12:22 PM) *
TANDEM has its own site with lots of detailed notes and a splendid slide presentation freely available. Can you point me towards anything similar for LAPLACE? Unfortunately the stuff linked in post 1 above seems to be password controlled.

some of the information are here http://jupiter-europa.cesr.fr/ (part of the content is also password controlled)
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ngunn
post Nov 20 2007, 04:19 PM
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Interestingly while TANDEM seems to be ahead of Laplace at ESA, from NASA we now have OPAG final reports for all the likely targets except Titan. I wonder if there is any significance in this?
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djellison
post Nov 20 2007, 04:22 PM
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I assume Ralph et.al. are still working on theirs.

Doug
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ngunn
post Nov 21 2007, 10:13 PM
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I assume so too, but I note that Ralph Lorenz, Jonathan Lunine and Carolyn Porco also all have their names on the cover of the ESA-instigated international TANDEM proposal.
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Guest_Geographer_*
post Nov 22 2007, 02:00 PM
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Guests






It seems pertinent to suggest ESA and NASA should coordinate missions to Jupiter and Europa to avoid redundancies. The NASA OPAG reports have several mission ideas to Jupiter and Europa around the same time scale. ESA could send a probe to Jupiter and NASA a probe to Saturn or Neptune, or at least use different instruments if they're both going to Jupiter.
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