March OPAG presentations available |
March OPAG presentations available |
Apr 8 2008, 09:37 PM
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#1
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Member Group: Members Posts: 704 Joined: 22-April 05 Member No.: 351 |
http://www.lpi.usra.edu/opag/march_08_meeting/agenda.html
LOTS of interesting material here. Some highlights that interested me: Cassini extended-extended mission (XXM) could last 7 years and end with a series of very close (10,000's km) polar orbits through the D ring gap to enable close in gravity and magnetometer mapping a la Juno Argo proposal would be a New Horizon's class fly by of a Trojan, Saturn, Neptune/Triton, and one or more KBOs for ~$800M (but requires radioactive power source, so would seem to be out of contention for next New Frontiers) Joint Jupiter mission design. NASA supplied Europa orbiter now required to conduct Jupiter system science including up to 4 Io flybys. To fit within the $2.1B cap (with 33% margin), Europa orbit would be reduced to 60 days and several instruments from the Flagship proposal would be dropped including the narrow angle camera) Titan mission. Aerocapture no longer allowed, so craft would enter Saturn orbit first. Potentially allows new Enceladus observations. (Editorial note: Presentation was long on concepts, short on specifics. If this is an indication of the maturity of the mission concept, this does not bode well. I hope that this is only the style of presentation chosen by the presenter). Nature of ESA in situ probe(s) to be decided. ESA Cosmic Vision outer planet mission. ESA is considering three missions for the next cosmic vision mission: an outer planets joint mission with NASA (Jupiter or Titan/Saturn), XEUS (X-ray observatory), or LISA (gravity wave observatory). Down select to two of the three end of '09, final single mission selected in 2011. Radioisotope power. Lots of technical update, but a gem in the backup, the ASRG (Sterling engine) mission concepts being studied in more detail than I've seen elsewhere: Moon polar rover (2 concepts) Titan boat(!) Io observer Trojan lander Comet lander Comet coma rendezvou sample return Mars lander drill ("a tour through Martian history") Venus balloons (2) -------------------- |
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Apr 17 2008, 03:56 AM
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#2
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Member Group: Members Posts: 307 Joined: 16-March 05 Member No.: 198 |
After reading the proposal for the Jovian OPF mission at the OPAG site what strikes me most is that it's really three separate missions bundled together and presented as one OPF! Not only would NASA, ESA, and JAXA each have their own orbiter, each of those orbiters would be launched on separate launch vehicles at (maybe widely varying) occasions.
Granted that each of those orbiters would have differing goals, but then that's hardly the point! Consider NASA's contribution, the Europan Orbiter. The report estimates it will cost $2.4 billion. Unfortunately, NASA only has $2.1 billion in the kitty to pay for it (which in turn has, not unnaturally, produced what I take to be a certain amount of handwringing). However, instead of ESA and JAXA riding to the rescue to make up the shortfall they will instead be spending their money on their own orbiters. Indeed if the ESA and JAXA will be contributing anything (other than science personnel) to the EO it is not spelt out in that document as far as I can make out. That is not say all three orbiters are not exciting, worthwhile endeavours, but is that really the way these international space missions are supposed to work? On the face of it it's difficult to call this one an international mission at all. With all due respect to those who put that presentation together it looks more like three national missions bundled together for marketing purposes. ====== Stephen |
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Apr 17 2008, 05:48 AM
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#3
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Member Group: Members Posts: 704 Joined: 22-April 05 Member No.: 351 |
On the face of it it's difficult to call this one an international mission at all. With all due respect to those who put that presentation together it looks more like three national missions bundled together for marketing purposes. ====== Stephen I would disagree. Each mission addresses key areas of Jovian science that no single craft can. One orbits Europa. Another conducts long term studies of Io and Jupiter and possibly orbits Ganymede. Another studies the magnetosphere in a second location, which has been a long term goal of the fields and particles community for Jupiter. Instrument development and science teams would be shared across all three missions. -------------------- |
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Apr 17 2008, 10:38 AM
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#4
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Member Group: Members Posts: 307 Joined: 16-March 05 Member No.: 198 |
Each mission addresses key areas of Jovian science that no single craft can. I do not doubt that at all, especially given the descoping of the version of the Europan Orbiter now being proposed versus the one proposed in this 2007 report to OPAG (caution! 95 mb PDF file). The one now being proposed appears to be the cheaper ($2.4 billion) "floor mission" rather than more expensive ($3.3 billion) "baseline mission" (see page 4-4 of that earlier report); and given that there is still a shortfall of some $300 million ($2.4 billion estimate vs $2.1 billion funding available) then chances are the EO may face more descoping before the project even gets the green light, much less flies--unless somebody rides to the rescue with more cash. (And given the past history of NASA projects ballooning in costs as development progresses even that additional descoping may not be the end of the bad news for the EO project.) A more sensible solution (just MHO) would have been for the Jovian OPF guys to settle on one or the other--either an EO or an JSO--to which both NASA and the ESA would contribute. By trying to have both (plus a possible Japanese orbiter) their ambitions may well wind up exceeding their funding levels. Instrument development and science teams would be shared across all three missions. Glad to hear it. But tell me: how much of NASA's $2.1 billion for the next OPF will be spent on ESA's JSO and how much ESA funding will be spent on NASA's EO? As far as I can make out there isn't enough for NASA to pay for that $2.4 billion EO plus make a sensible contribution to the JSO (which I see from the 2007 JSO report here (caution! 45 mb PDF file) will cost $3.1 billion for the "baseline mission" and $2.7 billion for the "descope mission" (page 1-4).) By my maths that means (assuming the descoped version of each) EO + JSO == $4.8 billion! How much of that is NASA going to be contributing towards? With Cassini NASA paid for 80% of the mission, with the ESA and the Italians paying the remainder. Will that be the split again? If so, then someone will need to tell Congress to come with a couple of billion dollars more! On the other hand given NASA's present committment isn't enough to even cover the cost of EO just how much will it be able to contribute towards the JSO? As far as I can see the major rationale for these international missions is to offset costs. If all NASA can contribute to the JSO is a few token pennies while the ESA won't be able to contribute much to the EO because it will have a $2.7 billion bill to pay for the JSO then will these really be INTERnational missions or will they turn out to be merely national ones with a little personnel mixing from foreign agencies? ====== Stephen |
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Apr 17 2008, 02:38 PM
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#5
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Member Group: Members Posts: 704 Joined: 22-April 05 Member No.: 351 |
A more sensible solution (just MHO) would have been for the Jovian OPF guys to settle on one or the other--either an EO or an JSO--to which both NASA and the ESA would contribute. By trying to have both (plus a possible Japanese orbiter) their ambitions may well wind up exceeding their funding levels. As far as I can make out there isn't enough for NASA to pay for that $2.4 billion EO plus make a sensible contribution to the JSO (which I see from the 2007 JSO report here (caution! 45 mb PDF file) will cost $3.1 billion for the "baseline mission" and $2.7 billion for the "descope mission" (page 1-4).) By my maths that means (assuming the descoped version of each) EO + JSO == $4.8 billion! I agree that in a perfect world, the best use of ESA's money for Jupiter would be to add an extra $600-800M (I forget the euro figures) into a single more capable craft. However, there are strong justifications for a second craft to do studies that a Europa-bound orbiter wouldn't want to linger around to do. I do not agree with your budget analysis. ESA's craft (without instrument costs, which are borne by the individual countries) is capped at that $600-800M. ESA will not be spending $2.7-3.1B. Based on Juno (which will cost about the same with instrument costs), a solar powered Jovian orbiter can be built for this price range. I have serious doubts about whether it can also orbit Ganymede, but it could do dozens of flybys at different longitudes and lattitudes. I think a craft that observes Jupiter and Io for a number of years and conducts many flybys of Ganymede is a good candidate mission. You apparently disagree, and that's what's makes forums interesting for all. -------------------- |
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