This paper describes a space flight experiment that demonstrated a space vehicle emergency black box transponder messaging system. The system utilized the Tracking and Data Relay Satellite System-Multiple Access (TDRSS-MA) for emergency messaging to ground controllers. The space vehicle Space Plug-n-Play Avionics or SPA interface supplies the telemetry da ta to the micro black box transponder. The micro bl ack box transponder transmits the message from the space vehicle to the TDRSS-MA Geosynchronous Satellite. The NASA White Sands Complex receives the signal from the TDRSS-MA satellite and demodulates the message, then routes it to the controllers. Rapid r esponse to system anomalies are now possible and can speed recovery and reduce the down time of complex space vehicles. This system is capable of hosting hundred s of users. The flight demonstration flew on May 4 th 2010 from Space Port America. The experiment was carried aloft