USMP-4 means United States Micro-gravity Payload-4 in
NASA
Similar to USMP-4
AA - Adverse Action
AA - Antenna Assembly
AAA - Avionics Air Assembly
AAC - Aft Access Closure
AACB - Aeronautics and Astronautics Coordinating Board
AAD - Attitude Anomaly Detector
AAFE - AeroAssist Flight Experiment
View all in NASA