A radar device aboard ESA's Mars Express orbiter has allowed scientists to peek beneath the surface from afar, and the success with this research is now prompting them to think up other spots in the solar system that would be ideal for this sort of examination.

NASA hopes to someday use a robot like Bill Stone's DepthX to explore Europa, a frozen moon of Jupiter and one of the most probably places in our solar system to support life.

In July, the space shuttle Discovery is slated to deliver two tons of hardware and supplies to the partially built International Space Station. This mission is paid for. As for the 16 more needed to finish assembly, as mandated by President George W. Bush two years ago in his Vision for Space Exploration policy, NASA is short by as much as $5 billion.