Workers perform a fit check on a Power Data Grapple Fixture (PDGF) in the Space Station Processing Facility. The PDGF is part of the payload on mission STS-98, a flight to the International Space Station. During the mission, the crew will install the U.S. Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the station with science research facilities and expand its power, life support and control capabilities