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

[hendric]

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

According to Wiki, about every 176 years

http://en.wikipedia.org/wiki/Planetary_Grand_Tour

But...We've learned alot about gravitational assists since Voyager, and I wouldn't be surprised if it is now possible to do a repeat tour or tours.

[Rob Pinnegar]

According to Wiki, about every 176 years

Yup. Uranus has now overtaken Neptune in its orbit, which means that we can't have a Grand Tour now. We have to wait for Uranus to catch up to Neptune again.

Since Uranus and Neptune are almost in a 2:1 orbital resonance, 176 years sounds about right. (That assumes Jupiter and Saturn will be well placed, of course.)