Commander Curt Brown then will maneuver Discovery away from the satellite, first to a short distance for a test of a communications link that will permit Spartan ground controllers to make fine pointing adjustments to one of the satellite's science instruments. Brown then will increase Discovery's separation to a distance of about 40 miles in front of Spartan. The satellite will be retrieved by Robinson using the robot arm on Tuesday. Spartan was unable to perform solar science studies last November following problems with its deployment during the STS-87 mission aboard Columbia. Spartan's two main instruments - the Ultraviolet Coronal Spectrometer and the White Light Coronagraph, will measure atomic temperatures and densities, as well as solar wind velocities in the sun's corona so scientists can better understand the forces that create solar wind, and the impact it has on the electromagnetic environment around the Earth.
Solar wind can have major impacts on communications technology on Earth.
Discovery's astronauts also will continue a battery of medical studies as they explore how the human body adapts to the weightless environment of space and how those changes compare with those seen as part of the aging process on Earth. Glenn will again provide blood samples as part of the Protein Turnover Experiment, which is looking at the balance between the building and breakdown of muscle. Discovery is orbiting the Earth every 95 minutes at an altitude of about 340 statute miles with all systems operating in excellent condition. The next STS-95 status report will be issued at approximately 6 p.m. Central time Sunday.