Europan Sub

Steven Squyres, lead investigator working with NASA's Opportunity rover on Mars, recently argued the next major planetary mission should be a Europan submarine to explore the huge ocean that seems to exist under the icy surface of the Jovian moon. Squyres and many other scientists think there's a good chance life could exist in that ocean.

Squyres admits that would be an extremely difficult mission to pull off-- landing on Europa, finding a way to get the submarine through what might be a miles-thick ice shell to the ocean, and finally navigating that ocean-- but the science pay off would be worth it, particularly if life is found. NASA probably agrees, but the question boils down to money. A Europan submarine mission would be extremely expensive, and NASA simply doesn't have the budget for such a mission, and likely won't have for the foreseeable future.

So, even though NASA's ultimate goal is to find life beyond Earth, the fiscal condition of the federal government will determine how quickly that goal will be pursued.