[X] My Assistant

[algorimancer]

Any showstoppers? I would envision something similar to the upcoming Mars Science Laboratory (RTG's are a given). Lot's colder on Titan... rough on lubricants, and parts would be brittle. Not sure whether the organics would pose a problem in the way of gumming up the works, but it doesn't seem likely at liquid methane temperatures. Smaller world, lower gravity, thick atmosphere... I'm inclined to think that a simple copy of the MSL, perhaps with some added insulation, would work just fine. The only alternative I've been hearing about is a balloon-borne probe, but that doesn't allow the same level of geologic prospecting.

[Guest_BruceMoomaw_*]

Titan balloons have a huge advantage over balloons to any other world in the Solar System -- including our own -- for the same reason that Titanian aircraft have one: Titan's unique combination of dense atmosphere and low gravity means that you need a much smaller balloon (or much smaller wings and propellers) to stay aloft, which in turn means that you can afford to make the balloon envelope out of thicker and tougher material than for a balloon on any other world.

As for the automated control problem: this is relieved in these proposed missions by the fact that the vehicle isn't supposed to come closer than 50-100 meters of the surface -- it will instead carry 5-10 tiny sampling harpoons (the design for these has been worked out in some detail, but they clearly require and will get more work) to drop down onto the surface and then reel back in on thin cables. This system should allow sampling to be done at heights of up to 200 meters above the surface, which provides the balloon a lot more latitude in avoiding dangerous terrain features. (The harpoon heads are little tripods which will hit the surface and instantly fire a small core tube downward into the surface, with the core tube then being released from the tripod and reeled back up to the gondola after less than a second on the surface.)

Given the apparent extent to which Titan's surface composition varies over long distances, this system (including using the gondola's aerial cameras for detailed reconnaissance of the types of Titanian surface features in the area) is regarded as a workable substitute for the need we would have otherwise to launch several fixed landers to different places picked out by previous orbital reconnaissance more detailed than Cassini will probably be able to do. However, clearly this whole subject is still open to lots more debate, and will get it in the near future.

As for the heat from the RTG on a lander or wheeled rover affecting the surface, this can indeed be solved by putting a cone-shaped thermal shield around the RTG to divert the air which it heats straight upward, keeping it from hitting the surface.