Pegasus Satellite Credit - NASA

Pegasus satellites consisted of vast detector panels deployed from Saturn IV stages on Saturn I test flights. They provided vital data on micrometeoroid density in low earth orbit for design of the Apollo spacecraft.

The mission of Pegasus, the Meteoroid Technology Satellite, was to define the magnitude and direction of medium size meteoroids in the near earth space environment. Three Pegasus spacecraft were sent into varying orbits, 500 to 800 km high, transmitting meteoroid detection information on a daily basis to the Fairchild Hiller-operated Satellite Control Center at Cape Kennedy. The spacecraft weighed 1450 kg, with a deployed wing 29 m long and 4.3 m high. Its 116 capacitor detectors of varying thickness provided over 185 square meters of area designed to count meteoroid hits for at least one year in space. It contained a solar cell powered battery power system, detection system, data processing and storage, real time and stored data transmission system, and temperature sensing and control and attitude sensing systems. The three spacecraft, launched in 1965, were still operational and returning useful data two years later. They represent the largest rigid deployable space structures developed up to that time. Prime Contractor was Space and Electronics Systems Division, Fairchild Hiller Corporation.

Typical orbit: 561 km circular orbit, 30.7 deg inclination. Mass: 10,450 kg (23,030 lb).

• 1965 February 16 - Pegasus 1 - Program: Apollo. Launch Site: Cape Canaveral. Launch Complex: LC37B. Launch Vehicle: Saturn I. Mass: 10,400 kg (22,900 lb). Perigee: 510 km (310 mi). Apogee: 726 km (451 mi). Inclination: 31.70 deg. Period: 97.00 min.
  A Saturn I vehicle SA-9 launched a multiple payload into a high 744 by 496 km (462 by 308 mi) earth orbit. The rocket carried a boilerplate (BP) CSM (BP-16) and, fitted inside the SM, the Pegasus I meteoroid detection satellite. This was the eighth successful Saturn flight in a row, and the first to carry an active payload. BP-16's launch escape tower was jettisoned following second-stage S-IV ignition. After attaining orbit, the spacecraft were separated from the S-IV. Thereupon the Pegasus I's panels were deployed and were ready to perform their task, i.e., registering meteoroid impact and relaying the information to the ground.

• 1965 May 25 - Pegasus 2 - Program: Apollo. Launch Site: Cape Canaveral. Launch Complex: LC37B. Launch Vehicle: Saturn I. Mass: 10,464 kg (23,069 lb). Perigee: 502 km (311 mi). Apogee: 740 km (450 mi). Inclination: 31.70 deg. Period: 97.00 min.
  Pegasus 2 was a meteoroid detection satellite. The Saturn I launch vehicle (SA-8) placed the spacecraft, protected by a boilerplate CSM (BP-26), into a 740-by-509-km (460-by-316-mi) orbit. Once in orbit, the dummy CSM was jettisoned. Pegasus 2, still attached to the second stage of the launch vehicle, then deployed its 29-m (96-ft) winglike panels. Within several hours, the device began registering meteoroid hits.

• 1965 July 30 - Pegasus 3 - Program: Apollo. Launch Site: Cape Canaveral. Launch Complex: LC37B. Launch Vehicle: Saturn I. Mass: 10,500 kg (23,100 lb). Perigee: 441 km (274 mi). Apogee: 449 km (278 mi). Inclination: 28.90 deg. Period: 93.40 min.
  NASA launched Pegasus 3, third of the meteoroid detection satellites, as scheduled at 8:00 a.m. EST, from Cape Kennedy. As earlier, an Apollo spacecraft (boilerplate 9) served as the payload's shroud. This flight (SA-10) marked the end of the Saturn I program, which during its seven-year lifetime had achieved 10 straight successful launches and had contributed immeasurably to American rocket technology.