Defense Advanced Research Projects Agency

And then there were eleven. Yesterday, the Defense Advanced Research Projects Agency (DARPA) announced that it had narrowed the field for its Urban Grand Challenge to just under a dozen robotic vehicles. 35 teams were part of this week's qualifying rounds.

The finalists, which include a truck, a Prius and a sedan, will be competing this weekend for $3.5 million in prize money. To finish, each robot has to complete a 60 mile course in under six hours. And there's going to be live traffic—roughly 50 human-driven vehicles will be on the road. The robots will even have to deal with four-way-stops. Which would be amazing, since that's something most humans can't even figure out. Tomorrow, watch the race live here.—Gregory Mone

More than 130 veterans of the Iraq war now face the daunting challenge of learning to live with a missing arm. To make that transition easier, the Defense Advanced Research Projects Agency, or Darpa, has launched a $55-million project that pools the efforts of prosthetics experts nationwide to create a thought-controlled bionic arm that duplicates the functions of a natural limb. If all goes well, by 2009 the agency will petition the Food and Drug Administration to put the arm through clinical trials.

So this is how the war in space might begin: not with a bang but a clank. On April 15, more than 450 miles above Earth, an experimental NASA spacecraft called DART (Demonstration of Autonomous Rendezvous Technology) fired its thrusters and closed in on a deactivated U.S. military communications satelliteand then gently bumped into it.

If you need to temporarily blind someone, consider the DEF3. It's the latest flashlight dreamed up by the U.S. government's Defense Advanced Research Projects Agency (DARPA)-and designed by optics experts Science Applications International Corporation with flashlight maker SureFire-for use as an Army-issue non-lethal weapon.