Recent Light Satellite Missions and Accomplishments in the DOD Space Test Program

Over the past 27 years, the US Air Force, as executive agent for the Department of Defense (DOD) Space Test Program, has flown approximately 325 space experiments for the Army, Navy, Air Force, and other DOD agencies not authorized their own means of spaceflight. These experiments have made significant contributions to the improvement of military technology and operations. This paper will include a brief review of the program overall status, various experiment capabilities being tested and the use of these experiment results in military activities. The paper's major theme will concentrate on three specific lightsat spacecraft from the broad range of test vehicles used by the Space Test program. These lightsats are currently undergoing testing or are actively manifested for spaceflight. The discussion of each host lightsat and its accompanying experiment will include experiment objective, lightsat design criteria, and status/results to date. Lightsats addressed include: 1) Space Test Experiments Platform (STEP). This standard STP lightsat bus has successfully carried its initial experiment, a Technology for Autonomous Operational Survivability (TAOS) payload and is programmed to perform three additional missions; Mission 1 (P90-1) which will carry four experiments, Mission 2 (P91-2) which will carry the Signal Identification Experiment (SIDEX), and Mission 3 (P92-2) which will carry five experiments. 2) Radar Calibration Satellite (RADCAL). Flying in a polar circular orbit it will primarily serve to calibrate over 50 worldwide C-Band radars used in launch and tracking missions. In addition, it will host three secondary experiments. 3) Advanced Photovoltaic and Electronic Experiment (APEX). This Pegasus-launched lightsat is hosting three experiments addressing: space power diagnostics, cosmic ray upset, and thin film ferroelectrics. The paper will conclude with a brief discussion of planned future light sat hosted experiments