I have tried to search but could not see any serious planning of sending a fly-by mission to Sedna. Does anyone have any info if the scientific community is planning such...?
In my opinion, Sedna would be very interesting target, far more interesting than any KBO etc. The fact that it spends most of the time outside heliopause under the influence of cosmic rays during aphelion could reveal some interesting results and also the reddish colour it has might be worth investigating. And good for us, at the moment it is approaching its closest point to Sun on its orbit, so mission to Sedna would not be such a big effort if done e.g. a'la NH with Jupiter gravity assist...? Maybe possible NH2 could be sent that direction.......?
Any comments, any info? Especially the fact that it is a body from outside the heliopause, could that add some interest towards it?
Unfortunately, I don't see this happening any time soon, for two reasons:
1.) Sedna even at its closet will be more than two and half times farther than Neptune.
2.) It's well beyond the plane of the Solar System, complicating any trajectory.
To be fair, I think Sedna would be an extremely interesting target. Any serious attempt to reach it, though, will probably have to wait for new propulsion technology.
I don't think that the roughly 80-90 AU distance of Sedna at the moment is too overwhelming, after all we have four (two of them functioning still) probes on that distance (and beyond) at the moment, and if we put that little probe on top of Atlas 5 like NH or some other Heavy configuration we could reduce the travel time to a reasonable level (<20 years). RTG's and components can handle that.
The issue of Sedna been so much out of the ecliptic plane does not concern me, after all, at the moment both Voyagers are over 30 degrees above/below the ecliptic, so not much less than Sedna is. And as Ulysses has shown, Jupiter can swing probes in various directions. Of course we might lose some velocity/time if bending the route 40-50 degrees but I don't think that's a critical factor here...? And I believe we should also have quite many launch window opportunities if we do only single fly-by (Jupiter) and then off to Sedna.
But of course, all this is just a meaningless daydreaming and speculation unless somebody puts the money on the table...
Jupiter can speed you up or get you off the ecliptic, but it's a tradeoff. I'd love to see a proposal that used Jupiter AND an ion drive to try to reach Sedna in under 20 years. Something that wouldn't fly by so fast as to be useless, of course.
--Greg
Jupiter-Sun gravity assist can get you going even faster. Of course the flyby will then be extremely brief.
How can you use Sun in a gravity assist? That's like using Earth in a gravity assist to get to the Moon. Unless you're thinking of a solar sail or ion engine providing delta-V during the Sun "flyby" in which case it makes a bit sense.
We had a 'what missions would you like to see' - type thread some time ago and I included Sedna in my list. I agree it's important, but to make it worthwhile I'd want to be fairly sure that the mission could definitively answer the question Did Sedna condense from the same solar nebula as the rest of the planets, or did it originate elsewhere? I think I suggested multiple impactors and spectral analysis of the resulting debris.
i would not expect to see a mission to Sedna till after NH reaches Pluto. This would give the enginers an idea what kind of sensors they would need. waiting till after 2014 or so will give time for more development of engines (post launch), and launch tech.
Does anyone know how much heliocentric escape velocity Voyager 2 got off of the 4 flybys (ok, so Neptune flyby wasn't really to pick up speed) as opposed to how much can one get just by a single, aggresive Jupiter flyby (skimming the cloudtops if you will)?
There are some more details (and numbers for Ulysses) here:
http://www.niac.usra.edu/files/library/meetings/annual/jun00/393McNutt.pdf
The mission concept on slide 8 describes a retrograde trajectory to Jupiter, followed by a Sun gravity assist involving an yet-to-be-developed propulsion system. Not to mention that there are a lot of other yet-to-be-developed proposed technologies, like the optical communications and Americurium RTG.
At least solar radiation would not be in short supply at 4 solar radii. I think that, if anywhere, is where the energy would come from.
True, but one has to think about how hot the semiconductors in the solar panels can get before dying on you. A quick, back of the envelope calculation gives 64 megawatts of solar radiation per square meter at 4 solar radii. That's running a tad hot.
Recently, https://iki.cosmos.ru/ researchers have analysed possible https://arxiv.org/ftp/arxiv/papers/2112/2112.13017.pdf for launch in 2029–2034.
I like the Neptune flyby one. It gives us an excuse to revisit Neptune along the way while the planets northern summer is beginning allowing mapping of Triton's northern hemisphere. Perhaps we could throw in an imaging encounter with one of the inner moons of Neptune too. Two birds with one stone.
2050 would be about equinox on Triton and would allow mapping of a lot of unseen territory, but note that Neptune's seasons are not the same as Triton's seasons.
https://www.researchgate.net/figure/Variation-of-the-subsolar-latitude-on-Triton-over-time-Triton-experiences-periods-with_fig1_355707178
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