Setting a spacecraft down on Mars isn't exactly easy—just ask Beagle 2. NASA's Phoenix Mars Lander, en route and due for a May 25 rendezvous with the surface, recently received a course adjustment from mission planners as they try to ensure that the craft doesn't drop down in a danger zone.

Japan's space agency gave it the OK. A famous astronaut says he'd get involved. They even tested a prototype in a wind tunnel. Still, it does sound nearly too off-the-wall to be true: Japanese scientists have teamed up with origami experts to design a paper airplane that could withstand re-entry and make its way from space back to Earth.

It's a name only a government agency could love: the Future, Fast, Flexible, Fractionated, Free-Flying Spacecraft United by Information eXchange. Could DARPA possibly come up with a more tortured title for System F6?

The penetrometer was the first thing to hit. The stick-like probe on the bottom of the Huygens lander punched aside a hard pebble made of water ice on the surface of Saturn’s largest moon, Titan, and sliced down through five inches of soft, muddy material. Scientists watching from Earth were ecstatic—the probe was not expected to survive the landing—but at the same time puzzled: If Titan really was, as they suspected, much like a young Earth, where were the liquid oceans predicted to cover the surface?