April 17, 2003

One of a Kind
Photo credit: Ken Bowersox, ISS Expedition 6 Commander, NASA

Explanation: Barn door trackers. Amateur astronomers on Earth love them because they're cheap and easy to build: Take a couple pieces of wood, a hinge, some knobs and nuts and bolts. Put them all together and you've got a device that can steer a camera and track the stars.

International Space Station science officer Don Pettit's barn door tracker, pictured above, is a little more sophisticated, but the spirit is the same. He assembled it using oddments and materials at hand onboard the ISS. "It's based on the fine gimbal movements in the IMAX camera mount for the Destiny Lab window. I figured out a way to mount a threaded screw and nut (scavenged from a Russian Progress rocket) and drive it with a Makita drill driver." The drill turns the screw, which moves the camera and its spotting scope.

This barn door tracker is one of a kind. But, of course, that's true of almost all barn door trackers. Ingenuity is the ingredient that makes each one unique.

Just after ISS commander Ken Bowersox took this picture of Don posing with his invention on April 5, 2003, Don attached the tracker to the Destiny Lab window and began taking pictures of city lights racing by on the earth below. Perhaps we'll get to see some of them in a future Picture of the Day.