Neptune Orbiter, Another proposed mission Options

[Rob Pinnegar]

This seems like a good place to start off the Uranus and Neptune forum: with the next ice-giants mission.

I will admit to not knowing a whole lot about the Neptune Orbiter With Probes (NOWP), other than the fact that it's in the planning stages, and a few other details I've gathered from Wikipedia and various other Internet sources. Anyone care to get this one going with a bit more information?

[elakdawalla]

I don't know much myself about what's possible either, but I know a good place to start would be to look up Thomas Spilker, who has done a lot of thinking about future Uranus and Neptune missions (he's also Cassini Deputy Project Scientist Linda Spilker's husband). He can talk your ear off very passionately about creative and mind-bending ideas for ways to tour giant planet systems, including one way to have an orbit that perpetually bounces on one side of a giant planet ring plane. I didn't understand the details -- I'd love it if someone could look into his publications and abstracts and figure out how this would work.

--Emily

[tedstryk]

I would really like to see a Neptune orbiter with a small Triton lander. I have also wondered about flyby missions, to at least check up on changes. Maybe this is a crazy idea, but I always thought that a Neptune flyby craft could be carried like a probe on a Jupiter or Saturn mission, and separate before JOI or SOI, and instead use its engines in conjunction with the gravity assist to accelerate on to Neptune.

[elakdawalla]

I would really like to see a Neptune orbiter with a small Triton lander.  I have also wondered about flyby missions, to at least check up on changes.  Maybe this is a crazy idea, but I always thought that a Neptune flyby craft could be carried like a probe on a Jupiter or Saturn mission, and separate before JOI or SOI, and instead use its engines in conjunction with the gravity assist to accelerate on to Neptune.

Well, it may be crazy, but it's not out of the mainstream crazy . In fact Sushil Atreya and Toby Owen are pushing for a mission concept called "Multiple Probes to Multiple Planets," which consists of a flyby spacecraft ("delivery truck") dropping two deep atmospheric probes at each giant planet. See
http://www.lpi.usra.edu/opag/feb_05_meetin...atmospheres.pdf
However I'm not sure when there would be a launch opportunity that would permit such a repeat of Voyager 2's flyby "grand tour" -- that would be my first question.
--Emily

[JRehling]

However I'm not sure when there would be a launch opportunity that would permit such a repeat of Voyager 2's flyby "grand tour" -- that would be my first question.
--Emily

Jupiter "laps" the outer planets every thirteen or so years, so opportunities will always keep coming around for J->U or J->N gravity assists.

I think a strategic plan is needed. Given the apparent rejection of NH2 as a Uranus flyby, it's a blank slate.

One nice bit of synergy is that Saturn, Uranus, and Neptune all have similar atmospheric profiles, so one probe design might accomodate all three. (Saturn's higher escape velocity may, however, mean that the Saturn probe would unavoidably arrive at higher velocity.) It would be nice to us Jupiter gravity assists to fling the two outer ones on their way, perhaps as add-ons, and get the synergy of unified manufacture and parallel investigations at three planets.

Proper flyby craft for remote sensing of the satellite systems (of Uranus and Neptune) are other options, but redundant if orbiters are planned, which for Neptune, at least, it should be.

Finally, there are an ever-increasing number of opportunities for KBO exploration and mini-Grand Tours. (Add in Sedna, which isn't a KBO!) I hope a broad view is taken in planning opportunities, because it could be a colossal waste to identify priorities, and pluck missions off of the top of the list, missing out on two-in-one possibilities.

[tedstryk]

If an orbiter is a long way off, I think a Triton flyby would be very useful, as it would allow for change detection since Voyager and, of course, when the orbiter finally gets there, its data can also be compared. Unlike the other moons of these two planets Triton is a dynamic world. Of course, the other issue is that the coverage of the Uranian moon's souther hemispheres is going to get poorer and poorer the longer we wait.