AFRL Completes Vibration Testing for DSX Satellite Trials Published Dec. 5, 2006 By Space Vehicles Directorate AFRL/VS KIRTLAND AIR FORCE BASE, N.M. -- AFRL scientists completed vibration testing of the High-Energy Proton Spectrometer (HEPS), which will serve as one of six instruments comprising the Space Weather and Environmental Effects trial on the Demonstration and Science Experiment (DSX) satellite, scheduled to launch in 2008. The evaluation simulated the spacecraft's launch environment and represented an important milestone in qualifying the instrument for flight. HEPS will measure high-energy protons and electrons in medium earth orbit (MEO) that adversely affect microelectronics, thermal materials, and optical coatings. Use of the resulting data will enhance space radiation climatology and specification/forecast models for the region. This outcome will lead to more realistic satellite design requirements for Air Force and Department of Defense system program offices, as well as for defense contractors. HEPS will also provide the military satellite operator with increased situational awareness for enhanced threat assessment and procedural planning. The MEO region is largely unexplored; numerous spacecraft have collected data almost exclusively in low earth orbit (LEO) or geosynchronous orbit (GEO). Intelligence, surveillance, and reconnaissance systems with 24-hour-a-day target and tracking requirements, however, would require only one-fifth the number of satellites for a similar system operating in LEO. Similarly, a high-speed communication constellation with global coverage would be four times closer than one in GEO, thereby reducing the overall power of the constellation by a factor of four. The HEPS instrument will also take measurements that will assist in specifying the orbital radiation environment for these future systems.