Smart robot orbs to aid space crews.

In one of the Star Wars movies, hero Luke Skywalker trains for his eventual clash with Darth Vader by wielding his light saber against a hovering robot orb. Soon, NASA will send similar-looking robots aboard spacecraft, the agency says.

Tests of the softball-size, red spheres, which will be packed with microelectronics and sensors, could start on the International Space Station in 2002. The spheres eventually would float around as mobile assistants to the crew.

This summer, NASA engineers demonstrated prototype navigation and control systems for the devices. They are now adding object-tracking and imaging capabilities to the machines.

Instead of martial training, the tagalong globes will offer information services, such as roving teleconferencing to Earth and optional reminding about scheduled tasks. The devices will be able to synthesize speech onboard and recognize language with the assistance of an external computer, says project engineer Hans Thomas of NASA's Ames Research Center in Mountain View, Calif.

The propeller-driven robots will also patrol the spacecraft interior, alert for gas leaks or other problems. They'll move approximately as fast as a person walks.

Howie Choset of Carnegie Mellon University in Pittsburgh has helped NASA develop this robot, as well as another to inspect spacecraft exteriors. He predicts spin-offs, including underwater versions to inspect seafloor drilling platforms.

Recalling the 1960s film 2001: A Space Odyssey, Thomas predicts that the robots will nudge NASA "toward a 2001-ish vision where the spacecraft takes care of itself, and the astronauts worry about the high-level goals."

However, that vision has a dark side: The film's spaceship-controlling computer, named Hal 9000, went berserk. Hal's degree of autonomy remains far off, Thomas says. "Hopefully, we'll be able to figure out how to keep the programs from getting paranoid," he chuckles.