See related story: Now That's Quite a Challenge

Despite their armor, the robotic Darpa drones are not invincible. Even Sandstorm -- the Carnegie Mellon University multimillion-dollar, pilotless Humvee that's the envy of most of the other teams here -- limped to the track after a near-death experience just a few days ago.

Team Phantasm, the first squad scheduled for qualification and inspection by Darpa officers Monday, had a sensor breakdown and missed its chance to qualify. The team will have another chance Tuesday.

A.I. Motorvator, a handcrafted, wedge-shaped drone, has had its share of false starts.
