S97-00248 (15 Dec. 1996) --- Astronaut Marsha S. Ivins, STS-81 mission specialist, arrives in a NASA T-38 jet trainer at the Kennedy Space Center's Shuttle Landing Facility for the Terminal Countdown Demonstration Test (TCDT). The TCDT represents a simulated final countdown until just before main engine ignition, now scheduled for Jan. 12, 1997.