Do you remember that scene in Star Wars where Ben Kenobi teaches Luke Skywalker how to use a lightsaber by having him spar against a spherical, flying robot? Scientists at NASA certainly do. In fact, they say that the little, laser-shooting droid inspired their their latest technical innovation, the Personal Satellite Assistant (PSA). Designed to assist astronauts with a number of tasks, it will soon be employed on the Space Shuttle and the International Space Station.
This talking, computerized device measures 6 in. in diameter (see the figure). Thanks to a set of six fans, it can "fly" in zero-G environments. A small LCD can display various lists and status information. The PSA also would have a wireless connection to the shuttle's or space station's computers, letting it access information about hardware, inventory, crew schedules, or science experiments. It would then relay that information to crew members as needed.
"If a crew member is taking something apart, the PSA could be floating over their shoulder and helping them by telling them 'Okay, remove this cover, take this latch off, move this wire over here,' and so on," says former PSA systems designer John Loch. "A floating, talking clipboard would be a good way to describe it."
With the help of automated voice-recognition and intent-interpretation technologies, the PSA can understand and respond to spoken questions and commands. This kind of intelligence also enables it to autonomously plan its own motions and actions, so the crew never has to worry about controlling it. More importantly, this lets it function in possible exploratory and emergency situations.
Another sci-fi classic, Star Trek, inspired some of the PSA's other functions. Astronauts specifically requested something like a "tricorder," the handheld device Captain Kirk would use to survey atmospheres on alien planets on that TV show. So, the PSA is equipped with sensors that detect the pressure and temperature of the ambient air, as well as concentrations of gases such as CO2. The PSA could then venture into situations that are too dangerous for human crew members.
The PSA can help earthbound scientists, too. Via the robot, researchers could watch crew members conduct experiments and offer advice and instructions when necessary. Mission controllers could use it to look around the station, check on experiments, investigate possible air leaks, and supervise other maintenance chores.
The robot's developers at NASA's Ames Research Center, Moffett Field, Calif., have been using off-the-shelf parts to help keep its costs down. Its computer is a Pentium III running Linux. The six ducted fans that provide propulsion are commercial products made for model airplanes. And, the infrared sensors it uses to avoid collisions are premade devices similar to those used in autoflush toilets.
Prototype PSAs have already been made. Next year, the PSA team will test the robot by taking it up in a KC-135 airplane, which can simulate a weightless environment by flying in parabolic arcs. For more information, go to http://science.nasa.gov, or to www.arc.nasa.gov.