 This is LDF, the Long Duration Exposure Facility. This school bus-sized satellite covered with samples of a variety of space-age materials has been circling the Earth since 1984. These samples will tell NASA what happens to spacecraft materials when they're exposed to the harsh environment of space for long periods, like they will be on space station freedom. NASA's original plan was to bring LDF home after about a year, but because the shuttle fleet was grounded for nearly three years, LDF has now stayed in orbit five times longer than once expected. The crew of the next space shuttle mission plans to use the orbiter's remote manipulator arm to grab the satellite and ease it into the cargo bay where it will be stowed for the trip back to Earth. It will mean the homecoming of more than 50 experiments, and while the delay has meant the loss of some data... On the other hand, without a doubt, the majority of the experiments are substantially enhanced by being up there the five years. Such is the case with an experiment developed by the University of Alabama at Huntsville and NASA's Marshall Space Flight Center. It measures the effects of atomic oxygen on surfaces at orbital altitude. The same stuff we breathe on Earth takes on a different form in space that literally erodes the surfaces of spacecraft over long periods of time. This unanticipated longer exposure to the LDF can provide considerable beneficial results in terms of studying these oxidation effects. That kind of information can be extremely crucial in the building of a space station. Any spacecraft has to survive for a long period of time in space. The benefits from LDF may be as varied as the experiments it carries. There are even millions of tomato seeds up there, which will soon be in the hands and the gardens of students, who may be the scientists of tomorrow. Although this scientific homecoming may be overdue in one sense, it will be just in time in another. Just in time, that is, to get as much exposure in space as is possible before LDF is destroyed returning to Earth on its own. In Huntsville, this is Mike Errington reporting.