Paul Loto'aniu and Juan Rodriguez, investigation of Galaxy-15 satellite failure

Paul Loto'aniu and Juan Rodriguez are CIRES research scientists with NOAA's Space Weather Prediction Center (SWPC). They were nominated for the CIRES Outstanding Performance Award in Science and Engineering for their investigation of the failure of the Galaxy-15 geostationary communications satellite, work that went beyond their normal duties as CIRES employees. Galaxy-15 experienced a debilitating anomaly that rendered the satellite useless and severely compromised the performance of the Federal Aviation Administration's Wide Area Augmentation System (WAAS). Following the Galaxy-15 anomaly announcement, the CIRES team assembled space environment data from a number of relevant sources, including the Geostationary Operational Environmental Satellites (GOES) that were in close proximity to Galaxy-15. Through a charged particle "moments calculation" and the local magnetic environment, the team showed that the space weather conditions leading up to the time of the anomaly had the potential for significant spacecraft charging, a situation that Galaxy-15 may have only experienced once before in its operational life. Electrostatic discharge is a established mechanism for disabling satellites in space. The environmental parameters representing extreme space weather conditions have now been folded into spacecraft charging modeling studies. This work has included a collaborative study with the Air Force Research Laboratory using the new GOES measurements to model both spacecraft surface charging and deep electric charging. Findings were presented at the 11th Spacecraft Charging Technology Conference (20-24 September 2010, Albuquerque, NM) and the 49th Aerospace Sciences Meeting (04-07 January 2011, Orlando, FL).