The video guidance sensor aboard the space shuttle Columbia featured eight fiber-coupled diode lasers as its essential components. The fiber-coupled lasers, manufactured by Opto Power Corp. of Tucson, Ariz., helped scientists from the Marshall Space Flight Center and NASA to gauge the changing distances between the shuttle and the Spartan satellite during a November rendezvous. Four of the eight 0.75-W lasers operated at 800 nm, while the others operated at 850 nm. Arranged in a ring surrounding the lens of the system's black-and-white camera, the lasers reflected off targets bolted to the satellite, providing scientists with information about the distance between the two craft. The satellite and the shuttle were to have docked, but the test proved unsuccessful because of an electrical malfunction. Plans for the video guidance sensor include operating it aboard an unmanned spacecraft that will dock with the planned international space station. Another unmanned mission in which the system may be used involves retrieving soil and rock from Mars.