AFRL COMPLETES SIX-YEAR SPACE MISSION TO MONITOR RADIATION ENVIRONMENT Published Dec. 11, 2006 By Plans and Programs Directorate AFRL/XP WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- (CEASE) recently completed a 6-year mission in low earth orbit, during which it monitored and mapped the near-earth radiation environment and provided real-time space environment hazard warnings to satellite operators. AFRL sponsored the June 2000 launch of CEASE aboard the Space and Missile Systems Center, Space Development and Test Wing, Triservice Experiments Mission-5 spacecraft along with the Missile Defense Agency-managed Space Technology Research Vehicle-2 payload. Originally flown with a 6-month operations requirement and a 1-year mission goal, the apparatus performance surpassed all expectations. Turned and initialized 1 day following liftoff, CEASE operated continuously until August 3, 2006, accomplishing more than 30,000 revolutions around the earth as it measured the radiation belts surrounding the planet. CEASE consisted of a small (10 x 10 x 8.2 cm), low-power (1.5 W), low-mass (1 kg) structure featuring five sensors for gauging the following hazards: total radiation dose, radiation dose rate, single-event effects, deep dielectric charging, and surface dielectric charging. The CEASE equipment also calculated incident electrons and protons and, using onboard data processing algorithms, produced hazard warnings transmitted to satellite facilities on the ground. As a result of these forewarnings, spacecraft operators were able to identify and understand radiation-environment-induced anomalies. Data produced by CEASE will enhance space radiation climatology and specification/forecast models. Its representations will lead to more realistic requirements for satellite designers, enabling improved risk/benefit trade-off decisions. CEASE data will also provide satellite operators with increased situational awareness for threat assessment and procedural planning. Meanwhile, CEASE II has been in operation aboard the Defense Support Program Flight 21 since August 2001, and a commercial version of the sensor--dubbed the Space Radiation Alarm--has been flying on a US telecommunications satellite since February 2005. A CEASE apparatus will also fly on the Demonstration and Science Experiments satellite, which is scheduled to launch in October 2009.