During a Spacelab flight, the hub of activity was the Payload Operations Control Center (POCC) at the Johnson Space Flight Center (JSC) in Houston, Texas. The POCC became home to the management and science teams who worked around the clock to guide and support the mission. All Spacelab principal investigators and their teams of scientists and engineers set up work areas in the POCC. Through the use of computers, they could send commands to their instruments and receive and analyze experiment data. Instantaneous video and audio communications made it possible for scientists on the ground to follow the progress of their research almost as if they were in space with the crew. This real-time interaction between investigators on the ground and the crew in space was probably the most exciting of Spacelab's many capabilities. As principal investigators talked to the payload specialists during the mission, they consulted on experiment operations, made decisions, and shared in the thrill of gaining new knowledge. In December 1990, a newly-established POCC at the Marshall Space Flight Center (MSFC) opened its door for the operations of the Spacelab payloads and experiments, while JSC monitored the Shuttle flight operations. MSFC had managing responsibilities for the Spacelab missions.