ExoMars ?
Preliminary design study was launched a couple of months ago.

So, if it's not NASA (too much vision), not Russia (never been interested) and not ESA (ExoMars will keep them busy)... who is going to take us back to Europa/Titan/Enceladus?

BTW, I thought I heard something like using a Saturn (I or V, don't remember) for launching a Viking style mission to Mars or even a Voyager type mission to the outer planets. Is there any truth in that?

Well, apparently no one. Not in the foreseeable future, anyway...


Sounds like another one of those ideas that were never meant to be. Like Prometheus & Jupiter Icy Moons Orbiter.

Cugel,

There were plans in the 1960s for a mission to land on Mars called... beleive it or not ... Voyager.
Those missions, I think planned to start in 1973, would have used Saturn launch vehicles. One plan I can recall even had a dual launch on top of a Saturn V !!!!!

Well, Voyager got canned due to the amazing costs (I think). Born out of the ashes was a slimmed down mission called Viking. Slimmed down, that is, at a then staggering final cost of one billion dollars (roughly 4 bilion today, I think).


A few years later, the TOPS mission - Thermoelectric Outer Planets Spacecraft - was also canceled due to the high costs. It was replaced by a slimmed down mission called Mariner Jupiter-Saturn. There are many stories of the ressurection of the mission.... one version has it that the OMB was actually surprised that TOPS was killed since they had bought into the idea of the economy of multiple spacecraft of identical design visiting so many new planets all in one mission. Thus, they were very receptive to a lower cost mission that addressed many of the same goals. Another point often made was that the very name Mariner implied design inheritance and continuation of a very sucessful program. Recall that Mariners were the first to Venus, Mars, and Mercury.

Several years into the program, I think people decided that since Viking was a snazzier name than something like Mariner Mars 75 would have been... why not do the same with mariner Jupiter-Saturn? Eventually, much to everyone's surprise, NASA came up with Voyager, in spite of the fact that the name was linked with a politically dead project.

I'm not sure what this portends for the future. I can't think how you could name a future mission JIMO for example... unless the acronym was changed to "JIMO - Justification for Incredible Monetary Overruns".

This online NASA book has the history plus images of the original Voyager mission
plans for landing probes on Mars:

http://www.hq.nasa.gov/office/pao/History/...12/on-mars.html

And check out these documents:

http://ntrs.nasa.gov/archive/nasa/casi.ntr..._1966020129.pdf

http://ntrs.nasa.gov/archive/nasa/casi.ntr..._1966020104.pdf

http://ntrs.nasa.gov/archive/nasa/casi.ntr..._1985024813.pdf

And - Conceptual Design Studies of an Advanced Mariner Spacecraft (all but Volume 2):

http://ntrs.nasa.gov/archive/nasa/casi.ntr..._1966005976.pdf

http://ntrs.nasa.gov/archive/nasa/casi.ntr..._1966005978.pdf

http://ntrs.nasa.gov/archive/nasa/casi.ntr..._1966005979.pdf

http://ntrs.nasa.gov/archive/nasa/casi.ntr..._1966005980.pdf

Thanks! Apparently, I got it mixed up.
Very interesting links!

There are some more details at http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1459.pdf :

"Key radiation areas include:

"(1) Flight Computer - A reliable, powerful, radiation tolerant flight computer (RAD750) has now been demonstrated in flight (e.g. Deep Impact and MRO), with over 100 ordered by a number of other customers.

"(2) Electronics – ASIC design and development are complete and are ready for flight qualification, and many new radiation tolerant electronic parts have been developed and are now available for use

"(3) Memory and Communication – A remaining problem in the radiation area is the development of radiation hard memory for science data. However, existing radiation hard SRAM technologies can be used to provide sufficient science capability when combined with operational scenarios and high rate downlink capabilities (< 300 kbps) made possible by the increased mass and power margins."


Regarding the biosterilization of Europa Orbiter, I may or may not have mentioned that the current strategy is to heat-sterilize all portions of the craft's avionics that are shielded from Jupiter's radiation, while just relying on that radiation to sterilize all exposed components of the craft. Those components will just undergo alcohol cleaning et al.

Here is an interesting new twist to the Europa Orbiter and SIM sagas. As posted on
NASA Watch, a letter from Rep. Wolf appears to be directing NASA to alter their
FY06 Operating Plan so that NASA obeys Congress' specific instructions to start
funding the Europa Orbiter project, and to maintain proper funding for SIM.

Doesn't this mean that Mike Griffin has now been warned that he is in danger
of breaking the law unless he immediately takes steps to comply with Congress'
directions?

You can check out the letter at this site.

http://images.spaceref.com/news/2006/Wolf....an.04.07.06.pdf



Another Phil

Actually, it isn't that dramatic. Wolf simply demands that NASA add another $28 million to aeronautics research and $30 million to the Mars program (with no specifications on how it should be spent), and that it "continue funding for Terrestrial Planet Finder [not SIM], and...begin planning for a mission to Europa in fiscal year 2006...With the exception of these significant deviations from Congressional direction, the Commitee has no objection to the allocations of funding proposed in your letter."

Besides the vagueness on just what that $30 million more for Mars is supposed to be for, Wolf doesn't give any order how much NASA should spend this year on Europa Orbiter planning (50 cents, maybe?) And I've said before that I think Terrestrial Planet Finder spending, like Mars Sample Return planning, can be safely delayed for several years until we have a better idea just what general kind of mission we actually want to fly. (In the case of TPF, there are two completely different possible mission concepts; and which of them should be chosen depends very strictly on Kepler's census of how common Earthlike planets really are -- something we won't have until 2012 at the earliest.) Nor does Wolf tell us what projects he thinks that funding should be pulled out of.

Here's a bit from Emily's write-up of the OPAG meeting:
http://planetary.org/blog/article/00000567/




my question: how does the "planetary protection" work for an Europa orbiter? Do they save enough fuel to crash it into Jupiter (that sounds like a lot of delta-V, but perhaps it's not that bad in the multi-body system. Any ideas?). Or do they keep the spacecraft as clean as they would for an impactor or lander? (I guess not, judging from the comment about the old mission).

I'll put in here the full sales pitch comparison from Karla Clark:

EO = Europa Orbiter (cancelled 2001)
EE = Europa Explorer (current idea from JPL)

Instrument mass: EO: 27 kg; EE: 180 kg
Instrument power: EO: 27 W; EE: 100 W
Number of instruments: EO: 4; EE: 10
Lander: EO: not possible; EE: 340 kg mass available (which had some audience members shaking their heads, as a chunk of that will be taken up in margin)
Duration: EO: 30 days; EE: 90 days plus
Data return: EO: 100 Gb; EE 3000 Gb
Extended mission possible: EO: none; EE: 125 days.

--Emily

Bob Pappalardo just answered part of this question in his presentation here at ISDC. The interior of the spacecraft -- instruments and electronics -- are sterilized. The outside can't be because it's, well, outside; at some point it contacts Earth stuff. Bob said that the radiation environment is so intense at Europa's orbit that the outside will be quite completely cooked after it gets into Eruopa orbit. Now -- that doesn't explain why the original Europa Orbiter proposal ran in to problems. Still need an answer to that part of the question.

--Emily

That's what was said at the Europa Focus Group, too. (I have no idea whether "Astronomy" will EVER get around to printing my small Web article on that meeting, although they did pay me for it -- and even if they do, I doubt it contains much by now that Emily hasn't since reported on her blogsite anyway. Grrrr.)

I don't know why they've eased up on sterilization requirements -- it may just be that they decided, after reexamination, that the initial ones were simply too costly and unjustified. I hope NASA isn't cutting corners on this; as the 2000 SSB report ( http://www7.nationalacademies.org/ssb/europamenu.html ) pointed out , if you get a single viable germ into Europa's ocean it could spread all the way around that world almost immediately -- which is not the case with Mars.

Two other notes about the redesigned Europa Orbiter (now rechristened "Europa Explorer", as Bob Pappalardo recently indignantly reminded me). First, (as Emily has also now pointed out), it now has a large gimballed, swivellable high-gain antenna, allowing it to take data and relay it back to Earth simultaneously and thus vastly increase its total data return. Second, besides the decision to utilize Earth and/or Venus gravity assists to send it to Jupiter -- which by itself utterly revolutionized the mission design by doubling or tripling the spacecraft's possible mass -- there's been another stroke of luck: the latest reanalyses of Galileo's radiation measurements indicate that the expected dose for a Europa orbiter is only half that previously estimated, allowing them to economize greatly on radiation shielding while still tripling the craft's previous 1-month design life in Europa orbit.

While BAE's roadmap claims they are working on a megarad-hard RAD750, the ones they've delivered are only rated to 100 krad, which is at least 3x too soft for the radiation environment we were working to for EO. Maybe they've moved that bar now.

There have been no dramatic technology breakthroughs. Any claim that a Europa orbiter has been enabled by such is simply marketing hype.

I just saw Emily's entry on the second day of the new OPAG meeting, which was devoted to discussions as to how to try to deal with NASA's space-science spending problems ( http://www.planetary.org/blog/article/00000573/ ). Cripes! In retrospect, it was an understatement for me to say earlier that space scientists have now hit the "Raft of the Medusa" stage -- they've now gone far beyond that, and are now eating not only each other but themselves. (They are, apparently, also now considering trying to save Europa Orbiter by cancelling not just the next Discovery and New Frontiers selections, but also the 2011 Mars Scout.)