The Tri Service Experiment mission 5, TSX 5, is a descendant of the Space Test Experiment Platform (STEP) common spacecraft bus, whose program missions included STEP-0, STEP-1, STEP-2, STEP-3, and STEP-4. TSX 5 is based on Orbital Sciences standard LeoStar bus. The spacecraft primary structure is a nominal 0.95 m (37.5 inch) point-to-point 12-sided structure which provides the required strength to carry launch and handling loads. The all aluminum structure consists of a honeycomb core plate with sheet metal panels mounted to milled longerons or stringrers. The 0.82 m (32.40 inch) long STRV-2 payload is mounted to the top of the spacecraft structure. A 0.97 m (38.00 inch) diameter marman ring and V-band separation system which attaches the space vehicle to the launch vehicle, transfers launch loads between the space vehicle and launch vehicle, and permits space vehicle separation from the launch vehicle following orbit insertion. The separation system is composed of a marman band/attach ring assembly, externally mounted pyrotechnic bolt cutters, separation springs, and electrical separation connectors. The spacecraft subsystems include an electrical power subsystem (EPS), a command and data handling subsystem (C&DH), a communications subsystem (COMMS), and an attitude determination and control subsystem (ADACS).

TSX 5 (source: USAF)

The TSX 5 mission is managed by the Space Technology Program (STP) at the Space and Missiles Centre, Test and Evaluation (SMC/TELS) at Kirtland AFB, New Mexico. The US$85 million mission is in support of the Space Technology Research Vehicle-2 (STRV-2) and Compact Environmental Anomaly Sensor (CEASE) experiments.

STRV-2 is a multi-national, highly integrated suite of experiments designed to push the envelope of space based imaging technology, satellite vibration suppression, and material science. STRV-2 is sponsored by the Ballistic Missile Defense Organization.

CEASE is an environmental scanner, providing the Spacecraft with essential knowledge about its surrounding space. CEASE will use this flight to prove its near spacecraft environmental assessment capabilities. CEASE is sponsored by Phillips Laboratory Geophysics Laboratory (PL/GPSP).

On July 1, 1996, the USAF Space Test Program awarded CTA Space Systems (acquired by Orbital Sciences in 1997) a US$25 Million firm fixed price contract to provide the TSX 5 mission, including spacecraft build, integration of Space Technology Research Vehicle -2 (STRV-2) and Compact Environmental Anomaly SEnor (CEASE), launch services, and on-orbit operations support.