Discovery Program 2006 and Missions Of Opportunity Options

[Guest_BruceMoomaw_*]

Faith Vilas, Discovery Program Scientist at the July 2002 "Discovery Program Lessons Learned Workshop" ( http://discovery.larc.nasa.gov/PDF_FILES/DiscoMinutes3.pdf , pg. 5):

"Q: Are there any major changes from the last AO [for the next one in 2003]?

"A: Mars, Phobos, and Deimos will now be in Mars Scout -- so they are no longer in
Discovery."

I've seen no indication that they have changed this back since. Jeff Bell -- who was associated with the "Gulliver" Deimos sampling mission -- has been bitching about it to me for some time. I will agree with him and you that it doesn't make any sense; but then, that fact means that it fits in very well with the US space program in general.

[Guest_AlexBlackwell_*]

Faith Vilas, Discovery Program Scientist at the July 2002 "Discovery Program Lessons Learned Workshop" ( http://discovery.larc.nasa.gov/PDF_FILES/DiscoMinutes3.pdf , pg. 5):

"Q: Are there any major changes from the last AO [for the next one in 2003]?

"A: Mars, Phobos, and Deimos will now be in Mars Scout -- so they are no longer in
Discovery."

I've seen no indication that they have changed this back since.  Jeff Bell -- who was associated with the "Gulliver" Deimos sampling mission -- has been bitching about it to me for some time.  I will agree with him and you that it doesn't make any sense; but then, that fact means that it fits in very well with the US space program in general.

Thanks. I must have missed the change, but now that I read those minutes, I do vaguely recall it. I do know that Dan Britt et al. originally envisioned Gulliver as a Discovery Program mission.

[djellison]

If you think about it - for Discovery money, you cant' really do anything Jovian or beyond.

Mars is out, Mercury's done and it's unlikely you'd get a nod for another Mercury mission the next decade or so ( at least until Messenger has lived out its primary mission ) - and VEX is likely to teach us what else we might like to learn about Venus, but not for 5 years or so. Then you have Lunar missions - with LRO basically stealing that scene for the next few years.

So you're left with Earth orbital and L1/L2 type missions (Genesis, Kepler), or Comets and Asteroids.

Doug

[tedstryk]

Well, for Venus, an atmospheric probe might be possible. I wonder about a Mercury hard lander. Also, a Jovian entry probe mission has been mulled in the past, but it has always died based on the fact that the science that could be done on a discovery budget may not justify the cost of getting there.

[Phil Stooke]

Venus is relatively easy to land on, compared with Mars at any rate. I would like to see quite a few more landings, targeted for specific geologic units. I think they could be done as Discovery missions. But we've covered this ground before!

Phil

[Guest_AlexBlackwell_*]

Jeff Bell -- who was associated with the "Gulliver" Deimos sampling mission -- has been bitching about it to me for some time.  I will agree with him and you that it doesn't make any sense...

It does make perfect sense, however, if NASA has no intention of flying a dedicated Phobos/Deimos mission. Moving "jurisdiction" for any such mission to the Mars Scout line, for all intents and purposes, is a death knell since Mars Scout proposals must be responsive to MEP scientific goals. Neither Phobos nor Deimos rate high (if at all) under MEP. At least in the Discovery Program, missions like Aladdin and Gulliver had a chance, so, in this rare instance, I'll have to agree with your example of Bell's "bitching."

This post has been edited by AlexBlackwell: Jan 26 2006, 07:23 PM

[Guest_AlexBlackwell_*]

Well, for Venus, an atmospheric probe might be possible.  I wonder about a Mercury hard lander.  Also, a Jovian entry probe mission has been mulled in the past, but it has always died based on the fact that the science that could be done on a discovery budget may not justify the cost of getting there.

Your examples show that there are many possibilities for non-cometary, non-asteroidal missions under Discovery, though a more significant cost cap increase would make alternatives more realistic.

[odave]

How about a solar mission - or has Sol's "low hanging fruit" already been picked?

[tty]

It does make perfect sense, however, if NASA has no intention of flying a dedicated Phobos/Deimos mission.  Moving "jurisdiction" for any such mission to the Mars Scout line, for all intents and purposes, is a death knell since Mars Scout proposals must be responsive to MEP scientific goals.  Neither Phobos nor Deimos rate high (if at all) under MEP.  At least in the Discovery Program, missions like Aladdin and Gulliver had a chance, so, in this rare instance, I'll have to agree with your example of Bell's "bitching."

It seems to me that the fastest and simplest way to obtain a varied sample of Martian material would be on Phobos. Rocks from every major impact on Mars must have ended up there and You don't have to go nearly as deep into the gravity well as for the surface of Mars.
Perhaps a mission for a future improved Haybusa?

tty

[Guest_BruceMoomaw_*]

Where solar studies are concerned, with one exception competed ones are suppposed to fall under the Explorer bailiwick rather than Discovery. The exception, of course, was Genesis, presumably because its main purpose was to do a really detailed isotopic analysis of the Sun's composition to provide additional insight on the formation processes of the planets. By itself, though, Genesis shows how fuzzy the borderlines between different basic branches of space science can be -- and again suggests the possibility that maybe NASA ought to lump ALL its competed missions within a single cost range together in one AO, rather than competing Discovery and Explorer (or New Frontiers and larger Explorers) separately. (The fact that small extrasolar-planet astronomy satellites are also put in the Discovery program rather than Explorer again shows the arbitrariness of this.)

[Guest_AlexBlackwell_*]

It seems to me that the fastest and simplest way to obtain a varied sample of Martian material would be on Phobos. Rocks from every major impact on Mars must have ended up there and You don't have to go nearly as deep into the gravity well as for the surface of Mars.
Perhaps a mission for a future improved Haybusa?

Actually, perhaps a better case can be made for Deimos, as Britt et al. do with the Gulliver Deimos Sample Return mission concept (e.g., Abstract 1, Abstract 2, Abstract 3).

This post has been edited by AlexBlackwell: Jan 26 2006, 11:47 PM

[Guest_BruceMoomaw_*]

As for Ted Stryk's suggestions: Venus entry probes are indeed plausible as Discovery missions, and in fact have been proposed from the very start of the program. So have Venus balloons: consider Ron Greeley's VEVA, which involved not just a balloon but one that would drop four little camera-equipped impactors as it blew over different parts of the planet.

But I imagine a Mercury hard lander, which would require a really major propulsion system, would probably be sufficiently costly that it would have to fall into the New Frontiers category (where it is one of the ideas being given serious consideration).

The same seems to be true of even a single Jovian entry probe (where presumably the goal would be to penetrate a lot deeper than the Galileo probe did, as well as coming down in a more representative part of the planet's atmosphere). However, one recent paradigm shift seems to be toward the idea that you don't really need deep entry probes to provide good compositional information on the other three giant planets -- and so the idea is now being strongly pushed that the next giant-planet entry probe mission should be a New Frontiers-class Saturn flyby that would just drop off two or three vented Galileo-type entry probes (or maybe even just one), with the flyby craft also observing the greater depths of Saturn's atmosphere with a Juno-type microwave spectrometer. This of course could also be done for Uranus or Neptune if we decided to do so before flying the much more complex Neptune Orbiter mission, although in that case you'd want to add a considerable number of other instruments to the flyby craft to make additional observations of the planet and its moons.

A Saturn Multiprobe Flyby, moreover, might be able to use solar power rather than an RTG -- just such a suggestion was made years ago, using a modified "INSIDE Jupiter" craft as the Saturn probe carrier, with no orbital insertion motor but a second pair of big solar arrays added.

[JRehling]

Other options would include smash-and-grab sample returns for airless bodies, with Mercury and Europa being the primary candidates of interest. Incidentally, an idea I don't recall seeing elsewhere would be a Stardust type mission with Saturn's *rings* as the object. (Jupiter's rings also an option.) Sampling the plumes of Io or Enceladus would also be possible, although if primitive species dominate, that would be a waste of money vs. a GCMS fly-through (which has been done, in both cases).

[Guest_AlexBlackwell_*]

A new document (Stardust Spacecraft Hibernation State) was added to the Discovery Program Library today.

[Guest_AlexBlackwell_*]

Presentations listed in the agenda for the Pre-Proposal Conference (February 2, 2006) are now online.