[X] My Assistant

[xtruel]

Hi,

I’m regular follower of NH and I’m also interested in the 2nd leg of the mission, i.e the 2016+ KBOs encounters. Does anyone know when operations about this leg (starting with searching objects of interest with HST or some other earth-based means, I suppose) are expected to begin ?

[xtruel]

Trouble is, it'll take NH almost 10 years to go 40 AU, and the inner edge of the Oort Cloud is estimated to be about 2000 AU out. A 500-year extended mission is probably asking for too much. :-)

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

Since Sedna's the only thing like Sedna, I think it'll be hard to guess that we'll find another before 2015 AND that it'll be reachable by NH.

That does raise an interesting question, though. From the NH mission page: http://pluto.jhuapl.edu/mission/mission_timeline.php it's not clear how much time NH could have to reach a KBO. A ten-year extended mission could roughly reach the perihelion distance of Sedna from the Sun, but is anyone contemplating an XM that long? How long can we reasonably expect NH to work?

--Greg

My former question may be reformulated as follows : After completion of extended mission at KB, NH’s mission officially ends. Spacecraft will be at something like 50 AU. Maybe some fuel will still be left. From this point, will be something else worth trying ? Previous outbound spacecraft (Pioneers, Voyagers) have all been maintained until they really die, we may expect the same for NH. I had in mind a possibility of targeting some object at scattered belt (however small it might be) which may be a SDO or an object currently cruising near perihelion whose orbit type is similar to Sedna (70-1000 AU or the like), thus qualifying as “inner Oort cloud object” as I’ve read somewhere. But according to Alan’s info I now believe this as unrealistic as SDOs are simply too far apart. So next possible milestone would be escape from heliosphere ?

This is very long term thinking, I agree…

[vjkane]

So next possible milestone would be escape from heliosphere ?

This is very long term thinking, I agree…

The Voyagers and Pioneers had capable particles and fields instruments. Anyone know if NH's SWAP and PEPSSI instruments would be good for exploration of the heliopause? Also, NH left Earth with a smaller than expected payload of plutonium. How far could it go and still (1) operate the instruments and (2) call home?

[Alan Stern]

The Voyagers and Pioneers had capable particles and fields instruments. Anyone know if NH's SWAP and PEPSSI instruments would be good for exploration of the heliopause? Also, NH left Earth with a smaller than expected payload of plutonium. How far could it go and still (1) operate the instruments and (2) call home?

We could probably run the s/c and 1 instrument to the mid-2020s to explore the heliosphere 50-70 AU, but that's not the mission-- the mission is to maximize the KB science, and that means spending all the fuel to do that.

Alan