5 ms·

I really hope to see a Cassini or Juno like probe to visit Neptune and Uranus in my lifetime. As good as JWST is and these images are, these objects are so dis

by cletus 4y ago

I really hope to see a Cassini or Juno like probe to visit Neptune and Uranus in my lifetime. As good as JWST is and these images are, these objects are so distant the only high-res imagery you can get is by visiting them. Prior to New Horizons, our best image of Pluto, for example, was a few blurry pixels and that remained the case even until New Horizons was 99% of the way there.

nkoren 4y ago
You may be in luck with Uranus: https://en.m.wikipedia.org/wiki/Uranus_Orbiter_and_Probe https://en.m.wikipedia.org/wiki/Uranus_Orbiter_and_Probe
- dotancohen 4y ago
  As I get older, that's always good to hear, doc.
  - edgyquant 4y ago
    Not only is this childish but the Gods name isn’t pronounced like that
    - 1123581321 4y ago
      Hey, I know! Those kinds of jokes are never funny. https://m.youtube.com/watch?v=x5lWowU52t8 https://m.youtube.com/watch?v=x5lWowU52t8
dylan604 4y ago
I would say I'd like this for all the planets. What Cassini and Juno brought us is simply stunning. Some of the details visible in Jupiter's clouds or Saturn's rings have just been amazing. The images Voyagers and New Horizons brought are nice and not to be discounted, but fly-bys vs orbit insertion missions just not the same. We should have oribters parked around each of our local major bodies. We should then have rovers on all of the solid bodies (that won't melt the thing in mere hours) after that. The MRO is such a great example.
- april_22 4y ago
  Even the Rosetta/Philae images of the comet 67P/Churyumov–Gerasimenko are out of this world! https://www.esa.int/Science_Exploration/Space_Science/Rosetta https://www.esa.int/Science_Exploration/Space_Science/Rosett...
  - dylan604 4y ago
    From that link: Launch: 2 March 2004 Mission end: 30 September 2016 Then, a bit lower on the page: 786 days in space Huh? Anyone got insights on what type of math was used here? Is there mm/inch type conversion problem? Am I just dumb? 12 years * 365 > 786.
    - avian 4y ago
      786 days is time spent in the vicinity of the comet. From 6 August 2014 (arrival at comet) to 30 September 2016 (mission end).
      - dylan604 4y ago
        But that's not what the words say. "In space" is stated specifically, not "Time in orbit" or some such. You're being very very generous
- WalterBright 4y ago
  If I had Bill Gates' money, I'd be funding that.
  - BurningFrog 4y ago
    Elon is fixing the launch cost side of it. If you have a probe design process that doesn't go through the US congress, it should be substantially faster and cheaper.
    - mildchalupa 4y ago
m3kw9 4y ago
I’m wonder if they can miniaturize a camera and propulsion system enough that can travel fast enough to just take pics and bring them back instead of needing large antennas/power modules to transmit back in say a year or so?
- nappy-doo 4y ago
  No. It's very hard to go fast, and to get to Neptune, you need to burn a lot of fuel to get there. Getting home needs a whole lot more fuel too. Space travel is hard. You can go with lower energy transfer orbits, and wait forever to get there, or you can go high-speed and carry a ton of fuel with you.
  - eesmith 4y ago
    Getting home requires no additional fuel if using a free-return trajectory and you don't want to be there for long. Jones, Drew Ryan, 2016, "Trajectories for flyby sample return at Saturn's moons", https://hdl.handle.net/2014/46163 https://hdl.handle.net/2014/46163, Root, V1 at https://dataverse.jpl.nasa.gov/file.xhtml?fileId=53873&version=1.0 https://dataverse.jpl.nasa.gov/file.xhtml?fileId=53873&versi... > Here an alternative and novel mission concept is analyzed to return a sample from either Titan or Enceladus, without capturing at Saturn. Instead, ballistic free return trajectories are sought which also incur a close encounter of the icy moon. The spacecraft could sample a plume (or upper atmosphere) during the hyperbolic flyby. The time frames are on the order of 20 years. OTOH, you would only have a few dozen hours near the planet. ("This 16 year mission, has the Titan flyby occurring about 10 hours prior to Saturn closest approach").
  - gpm 4y ago
    If you plot your trajectory so that you will just slightly in front of neptune, shouldn't you be able to use it's gravity to slingshot you back towards the inner solar system? I'm skeptical that it's worth it... because higher powered radios just aren't that expensive, but it's not obviously (to me) impossible either. Actually capturing your probe back in earth orbit... probably would be prohibitively expensive. But it seems like you could at least get it close by for a shorter communication distance.
mabbo 4y ago
I think part of the problem with that is just how far away Neptune is. Getting a probe like New Horizons to do a flyby requires a massive rocket. But to also have it be capable of slowing down to enter orbit and stick around means either it was moving slower on it's path to get there (so it takes a lot longer) or it has to carry a huge amount of fuel to burn to slow down (so it takes an even bigger rocket). Neither option is great.
- cletus 4y ago
  So for any of these destinations there are really two options: fly-by or orbit insertion. Pluto obviously was a fly-by. There were several reasons for this. Distance is a big one. Also, the more distant planets are the lower their orbital velocity. More distance = longer travel time. A higher velocity can reduce the travel time but you need to speed up at launch and slow down on arrival and that requires a higher delta-V budget. That requires extra mass of fuel, which becomes a vicious circle. Pluto is tiny and far so a fly-by was really the only option. Even then it took 10 years to get there. Neptune is more massive, closer and heavier. All of these help but if I'm reading [1] correctly, you'd still be realistically looking at a 30 year travel time for an insertion orbit. Having instruments hibernate for that long and work on the other end is really the biggest problem. We're entering an era of super-heavy lifters. Maybe these will meaningfully increase the practical delta-V budgets. Inserting a probe into orbit around Uranus (let alone Neptune) seems currently impractical just given how long it would take but that doesn't make me want it any less. Even a fly-by is better than nothing. But the delta-V for Saturn, Uranus and Neptune are all roughly the same [1]: https://en.wikipedia.org/wiki/Delta-v_budget https://en.wikipedia.org/wiki/Delta-v_budget
tzfld 4y ago
Actually, Juno is very limited in it's capabilities when it comes to flagship missions like Cassini. Talking about Jupiter, Galileo was in the same capability range as the Cassini.

by cletus 4y ago

nkoren 4y ago

You may be in luck with Uranus: https://en.m.wikipedia.org/wiki/Uranus_Orbiter_and_Probe https://en.m.wikipedia.org/wiki/Uranus_Orbiter_and_Probe

dotancohen 4y ago
As I get older, that's always good to hear, doc.
- edgyquant 4y ago
  Not only is this childish but the Gods name isn’t pronounced like that
  - 1123581321 4y ago
    Hey, I know! Those kinds of jokes are never funny. https://m.youtube.com/watch?v=x5lWowU52t8 https://m.youtube.com/watch?v=x5lWowU52t8

dylan604 4y ago

I would say I'd like this for all the planets. What Cassini and Juno brought us is simply stunning. Some of the details visible in Jupiter's clouds or Saturn's rings have just been amazing. The images Voyagers and New Horizons brought are nice and not to be discounted, but fly-bys vs orbit insertion missions just not the same. We should have oribters parked around each of our local major bodies. We should then have rovers on all of the solid bodies (that won't melt the thing in mere hours) after that. The MRO is such a great example.

april_22 4y ago
Even the Rosetta/Philae images of the comet 67P/Churyumov–Gerasimenko are out of this world! https://www.esa.int/Science_Exploration/Space_Science/Rosetta https://www.esa.int/Science_Exploration/Space_Science/Rosett...
- dylan604 4y ago
  From that link: Launch: 2 March 2004 Mission end: 30 September 2016 Then, a bit lower on the page: 786 days in space Huh? Anyone got insights on what type of math was used here? Is there mm/inch type conversion problem? Am I just dumb? 12 years * 365 > 786.
  - avian 4y ago
    786 days is time spent in the vicinity of the comet. From 6 August 2014 (arrival at comet) to 30 September 2016 (mission end).
    - dylan604 4y ago
      But that's not what the words say. "In space" is stated specifically, not "Time in orbit" or some such. You're being very very generous
WalterBright 4y ago
If I had Bill Gates' money, I'd be funding that.
- BurningFrog 4y ago
  Elon is fixing the launch cost side of it. If you have a probe design process that doesn't go through the US congress, it should be substantially faster and cheaper.
  - mildchalupa 4y ago

m3kw9 4y ago

I’m wonder if they can miniaturize a camera and propulsion system enough that can travel fast enough to just take pics and bring them back instead of needing large antennas/power modules to transmit back in say a year or so?

nappy-doo 4y ago
No. It's very hard to go fast, and to get to Neptune, you need to burn a lot of fuel to get there. Getting home needs a whole lot more fuel too. Space travel is hard. You can go with lower energy transfer orbits, and wait forever to get there, or you can go high-speed and carry a ton of fuel with you.
- eesmith 4y ago
  Getting home requires no additional fuel if using a free-return trajectory and you don't want to be there for long. Jones, Drew Ryan, 2016, "Trajectories for flyby sample return at Saturn's moons", https://hdl.handle.net/2014/46163 https://hdl.handle.net/2014/46163, Root, V1 at https://dataverse.jpl.nasa.gov/file.xhtml?fileId=53873&version=1.0 https://dataverse.jpl.nasa.gov/file.xhtml?fileId=53873&versi... > Here an alternative and novel mission concept is analyzed to return a sample from either Titan or Enceladus, without capturing at Saturn. Instead, ballistic free return trajectories are sought which also incur a close encounter of the icy moon. The spacecraft could sample a plume (or upper atmosphere) during the hyperbolic flyby. The time frames are on the order of 20 years. OTOH, you would only have a few dozen hours near the planet. ("This 16 year mission, has the Titan flyby occurring about 10 hours prior to Saturn closest approach").
- gpm 4y ago
  If you plot your trajectory so that you will just slightly in front of neptune, shouldn't you be able to use it's gravity to slingshot you back towards the inner solar system? I'm skeptical that it's worth it... because higher powered radios just aren't that expensive, but it's not obviously (to me) impossible either. Actually capturing your probe back in earth orbit... probably would be prohibitively expensive. But it seems like you could at least get it close by for a shorter communication distance.

mabbo 4y ago

I think part of the problem with that is just how far away Neptune is. Getting a probe like New Horizons to do a flyby requires a massive rocket. But to also have it be capable of slowing down to enter orbit and stick around means either it was moving slower on it's path to get there (so it takes a lot longer) or it has to carry a huge amount of fuel to burn to slow down (so it takes an even bigger rocket). Neither option is great.

cletus 4y ago
So for any of these destinations there are really two options: fly-by or orbit insertion. Pluto obviously was a fly-by. There were several reasons for this. Distance is a big one. Also, the more distant planets are the lower their orbital velocity. More distance = longer travel time. A higher velocity can reduce the travel time but you need to speed up at launch and slow down on arrival and that requires a higher delta-V budget. That requires extra mass of fuel, which becomes a vicious circle. Pluto is tiny and far so a fly-by was really the only option. Even then it took 10 years to get there. Neptune is more massive, closer and heavier. All of these help but if I'm reading [1] correctly, you'd still be realistically looking at a 30 year travel time for an insertion orbit. Having instruments hibernate for that long and work on the other end is really the biggest problem. We're entering an era of super-heavy lifters. Maybe these will meaningfully increase the practical delta-V budgets. Inserting a probe into orbit around Uranus (let alone Neptune) seems currently impractical just given how long it would take but that doesn't make me want it any less. Even a fly-by is better than nothing. But the delta-V for Saturn, Uranus and Neptune are all roughly the same [1]: https://en.wikipedia.org/wiki/Delta-v_budget https://en.wikipedia.org/wiki/Delta-v_budget

tzfld 4y ago

Actually, Juno is very limited in it's capabilities when it comes to flagship missions like Cassini. Talking about Jupiter, Galileo was in the same capability range as the Cassini.