Actually I disagree on the first submarine robot being free floating. There's no way, unless humans are nearby or we make some remarkable advances in AI (that we allow for this probe), that we can control such a robot.
How far along do we need to be before a serious sortie can be made to either Europa or Enceladus? I am thinking of a rather large capable robot on par with MSL.
Sometime before the end of this year, probably November, NASA, and ESA will pick the finalist for the outer planet flag ship mission. As stated by blackstar it will be either Europa or Titan.
Quote from: khallow on 07/02/2008 02:28 amActually I disagree on the first submarine robot being free floating. There's no way, unless humans are nearby or we make some remarkable advances in AI (that we allow for this probe), that we can control such a robot. What's the time delay to Jupiter?
A bit over an hour round trip at closest distance. Having said that, I changed my mind. A weighted probe that just drops at a controlled rate is a feasible submarine probe. No need for short term feedback from Earth with that sort of design. You need something that can communicate through that much water and ice though. Maybe use an extremely low frequency system like the ones on Earth. That greatly limits data, but allows you to communicate through a lot of stuff. A lot depends on the salinity of the water (if liquid water exists, apparently it's not yet certain) and the thickness of the ice.
Here's a completely uninformed but creative question: if the radiation environment around Jupiter is so harsh, is there a system analogous to a solar panel that could harness the energy for electrical power, be it incident radiation or simply passing through the field?
Quote from: khallow on 07/03/2008 02:34 amA bit over an hour round trip at closest distance. Having said that, I changed my mind. A weighted probe that just drops at a controlled rate is a feasible submarine probe. No need for short term feedback from Earth with that sort of design. You need something that can communicate through that much water and ice though. Maybe use an extremely low frequency system like the ones on Earth. That greatly limits data, but allows you to communicate through a lot of stuff. A lot depends on the salinity of the water (if liquid water exists, apparently it's not yet certain) and the thickness of the ice.My first question was to point out that we don't have real-time communication. If you send a probe, it's going to have to be able to operate on its own for long periods.As for a submarine probe, nobody should underestimate the difficulty of this. We have not even done it on Earth yet. There are so many obstacles to overcome it's mind-boggling. My own guess is that we won't do something like this for 80-100 years.
And by that point, we'll probably be running manned (or superduper AI) expeditions to these places anyway.
Even then, the microsub would only probably have a camera and a sample collection device; once a few "interesting" things have been collected, the sub can be winched back up to the lander and the samples chemically analysed...
Quote from: khallow on 07/03/2008 05:52 pmAnd by that point, we'll probably be running manned (or superduper AI) expeditions to these places anyway.You have a much more optimistic view of progress in space exploration than I do. I don't expect a human mission to Mars for another 50 years at least. As for sending humans to Jupiter? They'd fry.
One of the concepts for a cryobot is that it drops small hockey puck like relay transmitters as it melts its way through the ice. These become embedded and relay weak signals back up.
How about this: you land a lander on the surface at the thinnest thickness of ice you can find. Then you deploy a radioactive hockey puck that melts its way through the ice.
80-100 years is a long time. If someone sends people to Mars in 50 years, they still have 30-50 years to figure out the vagaries of a Jupiter expedition.
Quote from: Phillip Huggan on 07/04/2008 12:19 amHow about this: you land a lander on the surface at the thinnest thickness of ice you can find. Then you deploy a radioactive hockey puck that melts its way through the ice.Are you a nuclear engineer? What material do you propose to make this out of?
Quote from: khallow on 07/04/2008 12:00 am80-100 years is a long time. If someone sends people to Mars in 50 years, they still have 30-50 years to figure out the vagaries of a Jupiter expedition.I tend to think of these things in multiples of decades. In 2004 Bush announced plans to put humans on the Moon "no later than 2020." Well, 2020 will be roughly fifty years since the first Moon landing. So, in those fifty years, how much forward progress will we have made?--we will have returned to the starting line. So who's to say it won't take another fifty years after the first Mars landings just... to get back to Mars?
The best bet for the next flagship mission is a Huygens follow up, a Titan lander with a long lasting baloon floating in the thick atmosphere. The technologys available now and from the glimps we've had so far Titan looks to be the most dyamic terrestrial body in the solar system after Earth.Europa's a fascinating place but for a lander the really interesting stuff requires melting a submarine through possibly many meters of ice then transmitting data back through that same ice.
For example, if there is water breathing multicelled organisms in one of these places, they may be as sensitive to plutonium poisoning as we supposedly are to airborn plutonium. Then any plutonium power source would either have to be removed or designed so that compromise of the system isn't likely within a certain number of half lives of the fuel. We'll have to consider possible problems with heavy metals and some persistent manmade materials like fiberglass or nanoparticles.
As for Europa, nobody is talking about a lander anytime soon. The initial goal would be an orbiter that would do Jupiter science for a couple of years before settling in at Europa for up to a year. Only after the orbiter returns its data would anybody decide if a lander is worthwhile. In some ways that's an argument against Europa, because we know that we can do a lander at Titan already, so it's possible to get into the soup at Titan and do stuff. It's just that nobody believes that it's possible to find life on Titan, whereas they're not sure about Europa.
Nobody has inflated a balloon on another planet.
Quote from: Blackstar on 07/06/2008 02:09 amNobody has inflated a balloon on another planet.Erm, except for the Soviets on Venus in the 80s.
Quote from: Kaputnik on 07/06/2008 02:34 pmQuote from: Blackstar on 07/06/2008 02:09 amNobody has inflated a balloon on another planet.Erm, except for the Soviets on Venus in the 80s.Well, yeah, but that doesn't really count. Decades ago and by a group that's not us (plus: different planet) means that we don't know how to do it and have to start from scratch.
It doesn't hurt to ask for information. After all, a lot of NASA information is freely available to everybody, including Russians.
Quote from: gospacex on 07/06/2008 11:24 pmIt doesn't hurt to ask for information. After all, a lot of NASA information is freely available to everybody, including Russians.There are, in fact, Russian scientists who support American space programs. Lots more Russians working with the Europeans, actually.But look up ITAR sometime.
ITAR prohibits asking questions?!
Quote from: gospacex on 07/07/2008 04:38 amITAR prohibits asking questions?!It certainly stops people from answering detailed questions.
The Titan mission is a relatively safer look for some low-level value scientific data. Titan most resembles Earth, but no liquid water (maybe someone from NASA should tell the present administration it rains oil on Titan?). The ice Moons are lottery tickets for life. I'd be worried about polluting Ice Moons with microbes accidentally.