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Would a Curiousity/MSL class rover to Titan be a lot more difficult? Basically something that weighs a ton is being launched to a body that is 1.2 to 1.66 billion km distant vs. 59 million km to 97 million km. Communications time would be a lot greater, totally different environment active vs. relatively benign. Would a treaded/wheeled vehicle be a better choice/or a boyant one?
Vulcan Administrator
I think anything going to Titan would be a lot smaller than Curiosity at this stage. Also think that the most interesting components of Titan are the atmosphere and the lakes, which would explain why current proposals are looking at a hot air balloon (!) or a floater.
Everything I need to know I learned through Googling.
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Even on Mars the rover needs to be kept warm. My guess is that on Titan some very good thermal insulation is going to be needed just for the spacecraft to survive long enough to do some science.Originally Posted by banquo's_bumble_puppy
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Thanks. And congrats. on the landing you have raised alot of spirits on this dusty old ball of ours. It's amazing the enthusiasm surrounding this mission is really noticeable this time....people seem thrilled.
Order of Kilopi
IMO, sending something Curiousity-sized to Titan will probably have to wait until the era of assembled-in-orbit spacecraft, whenever that is.
STARGAZING: All I see are the lights of a billion places I'll never go. --Howard Tayler, Schlock Mercenary
Order of Kilopi
In some ways, sending probes to Titan would be easier than to Mars, in other ways, it would be harder. It takes significantly more delta V to get to Titan, though that can be somewhat mitigated if you are willing to live with a long travel time to take advantage of multiple gravity assists. However, Titan's atmosphere is fairly thick, wheras Mars's atmosphere is extremely thin. Titan's thick atmosphere combined with its low surface gravity means that the parachute used for Titan would not need to be as large as one used for mars, and it's possible that final descent would not even require rockets (or would require very small rockets), so the entire skycrane system would be unnecessary. Because of this, even though the mass of the spacecraft sent to Titan would be smaller (for a given launch vehicle), the mass of the lander as a percentage of the overall craft mass would be substantially larger, so it's possible that a Curiosity-class rover would be doable after all.
Vulcan Administrator
You can land on Earth using only parachutes and a heat shield. Titan has a thicker atmosphere and lower gravity, so it should be even easier.
Everything I need to know I learned through Googling.
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Now that would be cool. Can't believe they're prioritising Jupiter over that. Titan is surely one of the most important bodies in the Solar System to study.
Order of Kilopi
I wonder if there would be a danger of the waste heat of a Titan rover melting itself stuck.
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Is there any way to test that? I gotta think that there exists cold chambers that could test that out. Antarctica would be useful for that.
Established Member
^
The temperature would be easy to simulate, as would the pressure and composition. The composition of the surface is the big unknown.
Personally, I favor a slightly more cautious approach: a static but long-lived lander with an aerial component, something like the Vega missions v. 2.0. Or, a short-lived surface component (perhaps with a small, Sojourner-like rover) and a more advanced aerial one. Either way, I think we need more literal "ground truth" before we go rove on Titan. More relevant to the OP, I think any lighter-than-"air" mission will be more flexible than a lander, though one of the sophistication we'd need to do justice to Titan would be a bear to build and operate, IMO.
Order of Kilopi
With Titan's thick atmosphere, there's be plenty of cold wind for "air"-cooling. IMO, a radiator on top could keep enough heat from reaching the insulated wheels to prevent melting into the surface.
STARGAZING: All I see are the lights of a billion places I'll never go. --Howard Tayler, Schlock Mercenary
Administrator
I agree. But you might have to deal with the methane equivalent of mud, rather than the sand and rock of Mars. You might need a marsh buggy.
Established Member
I am afraid we need dedicated Titan orbiter capable of MRO-like resolution first before landing 1-ton rover in this frozen hell. Not coming any time soon.
Only landing contraption that I can see under current constraints is boat. Rockin' on surface of methane lake.
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Would something like HiRise be on any use through the clouds of Titan?
Order of Kilopi
Heh, that's what I love about Titan and what makes it so fascinating. The dense atmosphere and extreme cold mean liquid gases and ice play out the roles of water and rock on Earth, creating an environment that looks surprisingly familiar.
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A Titanian MRO would present unique problems. For instance:
*MRO orbits at an average altitude of 280 km. That's much too low for a safe orbit around Titan; its atmosphere is deep enough to exert significant drag much higher above it's surface than Earth's or Mars's. An orbit would probably have to be no lower than ~1,000 km to be stable over the long-term. Since this would be a three times higher than MRO orbits, its camera (already a huge half-meter in diameter) would have to be three times bigger for equivalent resolution, except that...
*--MRO is a visible camera, while Cassini's images of the surface are taken in the near-infrared, at wavelengths roughly twice those that MRO use (assuming a middle-of-the-road 500 nm for visible light). That doubles the aperture yet again, resulting in something like a 5-meter telescope to image Titan's surface at MRO's resolution. Even if I'm being too pessimistic, I can't see such an instrument being smaller than 2 meters.
However, if we stick with MRO's current equipment and simply soup it up for Titanian wavelengths, then we'd still get a very healthy resolution of about 3-5 meters...
Order of Kilopi
Actually, the sky-crane idea might work on Titan if it's attached to a balloon instead of a hover-rocket. Similar to an oceanic mission on earth, the mothership could float above the surface and dip various probes or even an ROV to the surface and then reel it back later.
A Titan reconnaissance orbiter might use a collapsible mirror for it's telescope.
Et tu BAUT? Quantum mutatus ab illo.
Order of Kilopi
Some thoughts on an Europa mission as a case study
http://forum.nasaspaceflight.com/ind...?topic=27140.0
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