The Relay Mirror Experiment (RME) was launched as a dual payload with LACE. Both satellites carried defense experiments intended to aid in design of space-based anti-missile lasers. RME validated stabilization, tracking, and pointing technologies at performance levels required for Strategic Defense Initiative (SDI) missions through a credible demonstration of a space-based relay mirror system. RME's 24-inch mirror was used to test laser pointing technology by deflecting ground-based beams back to earth.

RME's attitude control system malfunctioned immediately after launch, shutting off a reaction wheel. Nevertheless the Maui Optical Observatory atop Mount Haleakala established the first relay on 26 June 1991, with Kihei, Hawaii. The precision relay mirror was 24 in. (61 cm) and had a pointing accuracy of 0.2 arcsec. The payload also included the Wideband Angular Vibration Experiment (WAVE), which measured low-level angular vibrations affecting performance of acquisition, tracking, and pointing (ATP) systems.

Design Life: 6 months. Typical orbit: 457x478 km, include.=43.1 deg. Mass: 1,040 kg (2,290 lb).

• 1990 January 1 - Relay Mirror Experiment first successful laser relay -
  The Maui Optical Observatory atop Mount Haleakala established the first relay with Kihei, Hawaii.

• 1990 February 14 - USA 52 - Launch Site: Cape Canaveral. Launch Complex: LC17B. Launch Vehicle: Delta. Mass: 1,040 kg (2,290 lb). Perigee: 261 km (162 mi). Apogee: 281 km (174 mi). Inclination: 43.10 deg. Period: 89.90 min.
  Relay Mirror Experiment; also known as Losat-R. RME validated stabilization, tracking, and pointing technologies for Strategic Defense Initiative (SDI) missions through a credible demonstration of a space-based relay mirror system. The Wideband Angular Vibration Experiment (WAVE) measured low-level angular vibrations affecting performance of acquisition, tracking, and pointing systems. The experiment demonstrated that a laser beam can be accurately relayed from the earth to an orbiting satellite 450 kilometers away and then back to a 3-meter target on the ground. It achieved relay beam pointing accuracy which was 16 times better than the technical requirement. WAVE demonstrated the capability to discern platform disturbance amplitudes of a few nanoradians at discrete frequencies and is therefore a candidate to fulfill similar requirements for future ATP experiments.