An artist's concept showing TRW's small lunar subsatellite being ejected into lunar orbit from the SIM bay of the Apollo 15 Service Module. The 80 pound satellite will remain in orbit a year or more, carrying scientific experiments to study space in the vicinity of the Moon. The satellite carries three experiments: S-Band Transponder; Particle Shadows/Boundary Layer Experiment; and Subsatellite Magnetometer Experiment.