Stock Photo - 07/23/1997 __ STS_85 Payload Commander N. Jan Davis left and Mission Specialist Robert L. Curbeam, Jr., go through countdown procedures aboard the Space Shuttle orbiter Discovery during Terminal Countdown Demonstration Test TCDT activities for that mission. The TCDT includes a simulation of the final launch countdown. The primary payload aboard the Space Shuttle orbiter Discovery is the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere_2 CRISTA_SPAS_2. Other STS_85 payloads include the Manipulator Flight Demonstration MFD, and Technology Applications and Science_1 TAS_1 and International Extreme Ultraviolet Hitchhiker_2 IEH_2 experiments