OPAG Reports, Formal proposals/evaluations of future outer SS missions |
OPAG Reports, Formal proposals/evaluations of future outer SS missions |
Nov 9 2007, 08:28 PM
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Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
http://www.lpi.usra.edu/opag/announcements.html
That's one little URL with a lifetime's worth of reading material. Three detailed studies are available in PDF format. The missing body is Titan, which will be the subject of a forthcoming report. The three focus missions are: Europa Explorer: Fairly detailed description of a mission that is pretty much what Europa Orbiter would have been. Jupiter System Observer: Basically, Galileo 2 (without the antenna mishap!). The craft would start with a 3-year tour of all the Galileans, then spend 1 year in an elliptical Ganymede orbit, then the rest of the mission in a tight, polar Ganymede orbit (like MGS at Mars). That would map the heck out of Ganymede, but also be close enough to the rest of the system to make long-range observations for years. Note that Ganymede would thereby provide a lot of radiation shielding. Enceladus: where three profiles are examined in depth: Enceladus Orbiter only; Enceladus Orbiter with soft lander; Saturn orbiter with Enceladus soft lander. There's more to chew on here than I have had (or may ever have) time for, but I'll throw in my two cents' worth: Seems like a Europa-only mission would only benefit from coming after a JSO. EE would explore Europa much better than JSO would; why even have JSO observations at Europa if EE came first? In many ways, these two missions are competitive. EE would have the big payoff, but JSO seems like basic recon that would prime EE, especially giving specs on radar performance. But if we waited til JSO was 4 years into its mission before completing design of EE, then put EE sometime mid-century. If an Enceladus mission included a Saturn orbiter, then maybe the same orbiter could provide data relay for separate Titan elements. However, a lot of the Enceladus science goals would require an Enceladus orbiter, so I don't think a Saturn orbiter for Enceladus/Titan will win out. Note that Enceladus orbital velocity is low enough that the craft could manage to take lots of hits from ice pellets and survive. Put a bulletproof vest on the craft and let it soar through the plumes endlessly. |
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Feb 14 2009, 07:28 AM
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Junior Member Group: Members Posts: 26 Joined: 13-August 05 Member No.: 464 |
The studies I've seen, e.g. that from Tibor Balint (~2004) on the proposed Europa Lander (the ESSP) there was a feasible battery powered mission, giving it a life of approximately 3 days on the surface. I can't remember whether it was Li-ion rechargeable from the carrier spacecraft RPS before landing, or a primary cell (Li FeS, Li Ag V, Li Thionyl Chloride etc.) May or may not have had RHUs. I imagine such battery technology would be available to IKI - the end of the JEO study report does mention a meeting with IKI on a potential lander element, which is cheering.
More recent study here quotes 600-820Kg mass required for a soft-lander, c.f. previous 300-500Kg (http://ippw.jpl.nasa.gov/20070607_doc/4_15RAGE.pdf), maybe if everything else came in under the mass budget, and an upgrade to Delta IV-H from the Atlas 551. It just seems such a crucial and rare opportunity, if the JEO does get up (obviously far from certain!) Anyway, I know Europa landing topic has been discussed to exhaustion, apologies. Roly |
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Feb 14 2009, 04:51 PM
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Junior Member Group: Members Posts: 39 Joined: 29-September 05 Member No.: 518 |
The studies I've seen, e.g. that from Tibor Balint (~2004) on the proposed Europa Lander (the ESSP) there was a feasible battery powered mission, giving it a life of approximately 3 days on the surface. I can't remember whether it was Li-ion rechargeable from the carrier spacecraft RPS before landing, or a primary cell (Li FeS, Li Ag V, Li Thionyl Chloride etc.) May or may not have had RHUs. I imagine such battery technology would be available to IKI - the end of the JEO study report does mention a meeting with IKI on a potential lander element, which is cheering. More recent study here quotes 600-820Kg mass required for a soft-lander, c.f. previous 300-500Kg (http://ippw.jpl.nasa.gov/20070607_doc/4_15RAGE.pdf), maybe if everything else came in under the mass budget, and an upgrade to Delta IV-H from the Atlas 551. It just seems such a crucial and rare opportunity, if the JEO does get up (obviously far from certain!) Anyway, I know Europa landing topic has been discussed to exhaustion, apologies. Roly Well, I take back what I said. 3 days on batteries is pretty exciting. And I think the Russians could supply a battery powered lander... and I think an 800 kg lander should definitely be possible (TSSM gets ~800 kg of in situ payload all the way to Saturn) |
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Feb 19 2009, 06:11 AM
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#4
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Member Group: Members Posts: 307 Joined: 16-March 05 Member No.: 198 |
In another sign of the pending apocalypse, I wrote a post about Europa: http://gishbar.blogspot.com/2009/02/thickn...l-from-jeo.html Hey, careful there! Let's not jinx the poor little JEO. ====== Stephen |
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