Exploring Titan

Mission planners studying ways to explore Saturn's magnificent moon Titan within the next few years are looking at several possibilities. The big element guiding their work involves deciding whether to try to cover a large area to get a broad overview, or, alternatively, study a smaller area in more detail.

If they choose the latter approach, the obvious choice would be to send a lander partnered with a rover. We know how to do that, but pulling it off on Titan would be a real challenge. For one thing, because of the distance between Earth and Titan, a rover there would either have to move extremely slowly, or it would need to be able to navigate and make decisions largely on its own-- in what is likely a more dynamic surface environment than the one on Mars, for example.

Covering a large area would require using aircraft; Titan's thick atmosphere allows a range of options. Lighter-than-air vehicles could fly high, studying the atmosphere, or fly under the haze layer to map large tracts of the surface. Hot-air balloon-type craft could also be used. Even jets are a possibility. A jet aircraft might be able to circumnavigate Titan at relatively low altitude in several hours.

Combining those two basic options might also be possible. A blimp or a balloon, for example, could drag an instrument package along the ground as it flew, thus sampling both sky and surface. Deciding exactly how best to go after Titan's mysteries in an era of extremely limited budgets will be at once a difficult and a fascinating exercise.