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Tom Mazanec
2016-Apr-13, 04:15 PM
Now that the Pluto flyby is receeding into history, is there any chance of getting a flyby of Pluto's "twin", Eris?

EDIT: Sorry, I put this in the wrong forum. Please move to space exploration.

antoniseb
2016-Apr-13, 05:44 PM
moved to Space Exploration.

... Or a Sedna flyby, or, if we find it, a Planet Nine flyby?
I'm guessing the answer is "not anytime soon".
Perhaps when we start using some kind of fusion powered ion drive to get humans to Mars, it won't be too big a deal to launch a high speed probe on a long mission, and there will be more frequent efforts to explore the cold dark reaches of the Sun's influence (and beyond).

Tom Mazanec
2016-Apr-13, 05:51 PM
Yeah...Quaroar, Ixion, Varuna, Makemake, Haumea, Orcus.... There are quite a few prospects.
Here are a couple Next Big Future posts which may be pertinent:
http://nextbigfuture.com/2016/04/nasa-funds-direct-drive-fusion.html
http://nextbigfuture.com/2016/04/nasa-testing-electric-solar-sail-for.html

antoniseb
2016-Apr-13, 06:40 PM
Yeah...Quaroar, Ixion, Varuna, Makemake, Haumea, Orcus.... There are quite a few prospects. ...
I think it is oddly shaped Haumea that I have the biggest curiosity about.

publiusr
2016-Apr-16, 07:44 PM
I think it is oddly shaped Haumea that I have the biggest curiosity about.

Same here.

I wounder if--should that thing come apart--would it sling anything towards the inner solar system? or is the spin such that debris wouldn't be aimed right at us?

cjameshuff
2016-Apr-16, 08:13 PM
There's probably relatively minor differences between them and the range of bodies represented by Pluto/Charon, and any given flyby mission is only going to get a brief glimpse at one of them. I would favor a Neptune orbiter, which would allow for long-term study of Triton. Such study would give us a better idea of which Kuiper belt bodies to focus on next and what instruments to send their way.



Same here.

I wounder if--should that thing come apart--would it sling anything towards the inner solar system? or is the spin such that debris wouldn't be aimed right at us?

Just how much delta-v do you expect such an event to apply to the debris? The debris would result in a family of objects in fairly similar orbits to the original.

publiusr
2016-Apr-16, 08:20 PM
Not on its own of course--but if hit by something else that was also in-bound.

cjameshuff
2016-Apr-16, 08:41 PM
Not on its own of course--but if hit by something else that was also in-bound.

Then that depends on the velocity imparted by the impacting object. If it can blast debris away at the some-km/s required to bring it into Earth-intersecting orbits, a few hundreds of m/s contributed from the rotation only means it'd have to hit at a different angle.

selvaarchi
2016-Apr-16, 11:53 PM
Now that the Pluto flyby is receeding into history, is there any chance of getting a flyby of Pluto's "twin", Eris?

EDIT: Sorry, I put this in the wrong forum. Please move to space exploration.

That will only give us repeat of New Horizon. I prefer what Dawn did - get there and take your time with the exploration and then move on to another target. We have more options with new technology that I am sure will be able to slow the spacecraft down to where the ion engines can take over. So instead of a one shot opportunity it will allow us to pick new targets as we learn more about this area in space of which we know so little about.

cjameshuff
2016-Apr-17, 04:11 PM
That will only give us repeat of New Horizon. I prefer what Dawn did - get there and take your time with the exploration and then move on to another target. We have more options with new technology that I am sure will be able to slow the spacecraft down to where the ion engines can take over. So instead of a one shot opportunity it will allow us to pick new targets as we learn more about this area in space of which we know so little about.

The distances involved and the low accelerations and high power requirements of ion drives mean that such a mission would be very long duration and would require a nuclear power source. The presence of a gas giant to capture the probe makes it significantly easier to keep a probe in the vicinity of Triton.

It's also likely a probe would require multiple km/s of delta-v after arriving at the first target to reach a second one. If you launch a probe to enter orbit around a Kuiper belt object, you would likely be better off giving it extra instruments and leaving it in permanent orbit for long term study rather than spending mass on propellant to allow it to reach a secondary target. Multi-target missions are really only feasible for gas giant moons, asteroids, etc.

selvaarchi
2016-Apr-17, 04:23 PM
The distances involved and the low accelerations and high power requirements of ion drives mean that such a mission would be very long duration and would require a nuclear power source. The presence of a gas giant to capture the probe makes it significantly easier to keep a probe in the vicinity of Triton.

It's also likely a probe would require multiple km/s of delta-v after arriving at the first target to reach a second one. If you launch a probe to enter orbit around a Kuiper belt object, you would likely be better off giving it extra instruments and leaving it in permanent orbit for long term study rather than spending mass on propellant to allow it to reach a secondary target. Multi-target missions are really only feasible for gas giant moons, asteroids, etc.

Pity if that was the case as having a probe on standby so to say in the Kuiper belt would be nice foe example when a planet 9 turns up. We know so little of that area that to have a probe to study the environment in that region will greatly enhance our knowledge of that area.

cjameshuff
2016-Apr-17, 06:38 PM
Pity if that was the case as having a probe on standby so to say in the Kuiper belt would be nice foe example when a planet 9 turns up. We know so little of that area that to have a probe to study the environment in that region will greatly enhance our knowledge of that area.

If it shows up, any given probe already in the Kuiper belt is likely to be further from Planet 9 than Earth is, and centuries of travel from it if it's possible at all to reach it. The Kuiper belt isn't just a place that's far away, it's a volume of space about a hundred AU across, with Earth orbiting 1 AU from a point right in the middle of it. At the inner edge, Pluto takes 248 years to complete an orbit. The hypothesized Planet 9 would have a closest approach to the sun of about 200 AU, and might take 15000 years to complete an orbit.

selvaarchi
2016-Apr-17, 08:56 PM
If it shows up, any given probe already in the Kuiper belt is likely to be further from Planet 9 than Earth is, and centuries of travel from it if it's possible at all to reach it. The Kuiper belt isn't just a place that's far away, it's a volume of space about a hundred AU across, with Earth orbiting 1 AU from a point right in the middle of it. At the inner edge, Pluto takes 248 years to complete an orbit. The hypothesized Planet 9 would have a closest approach to the sun of about 200 AU, and might take 15000 years to complete an orbit.

I do realize it is a big area but after Pluto showed it was an active planet, just imagine what Planet 9 would be like. What other surprises are there in this mysterious area? If we can think of a mission to our nearest star, why not one to our own back yard. It should be a mission that should last 50 to a 100 years - our own little "Star Trek" :D

cjameshuff
2016-Apr-17, 10:16 PM
I do realize it is a big area but after Pluto showed it was an active planet, just imagine what Planet 9 would be like. What other surprises are there in this mysterious area? If we can think of a mission to our nearest star, why not one to our own back yard. It should be a mission that should last 50 to a 100 years - our own little "Star Trek" :D

You're missing the point. If a probe orbiting in the Kuiper belt could be redirected to reach it, which is overwhelmingly unlikely, it would most likely arrive hundreds of years after Planet 9 had been thoroughly explored by probes launched from Earth.

selvaarchi
2016-Apr-19, 05:49 AM
You're missing the point. If a probe orbiting in the Kuiper belt could be redirected to reach it, which is overwhelmingly unlikely, it would most likely arrive hundreds of years after Planet 9 had been thoroughly explored by probes launched from Earth.

You could be right but I am happy to read that NASA is looking at options to shorten the flight times to Pluto (http://www.parabolicarc.com/2016/04/16/niac-focus-fusionenabled-pluto-orbiter-lander/) (read Kuiper belt - my interpretation) and with a orbiter and lander as well :D