LES Credit - NASA

The LES spacecraft were designed and built by MIT's Lincoln Laboratory in Lexington, Massachusetts, as part of the an Air Force-sponsored program to test in orbit new devices and techniques for use in military satellite communication systems.

LES-5, launched July 1, 1967, was designed primarily to aid in the development of a tactical satellite communication (TACSATCOM) system for the Department of Defense. It was used for the first communications by satellite among Army, Navy, and Air Force units, including aircraft in flight, submarines and surface vessels, and a variety of ground terminals. LES-5 was the first communication satellite to operate entirely in the government-allocated UHF-band (225-400 MHz), and it carried the first UHF-band satellite antenna system that generated circularly polarized radio signals to minimize fading and communication dropouts and to allow a surface terminal to use a very small, simple antenna such as a whip or stub monopole. LES-3, a UHF-band radio signal generator launched in December 1965, helped to establish design criteria for LES-5. LES-1, -2, and -4, also launched in 1965, operated at X-band (approximately 8,000 MHz), and successfully tested a number of important new devices and techniques, including the first all-solid-state communication satellite transmitters and the first "electronically despun" (earth-sensing and antenna-beam-switching) system to increase the effective radiated power from the satellite.

Typical orbit: 21478 km circular orbit, 22 deg inclination.

• 1965 February 11 - LES 1 - Launch Site: Cape Canaveral. Launch Complex: LC20. Launch Vehicle: Titan. Mass: 31 kg (68 lb). Perigee: 2,783 km (1,729 mi). Apogee: 2,809 km (1,745 mi). Inclination: 32.10 deg. Period: 145.80 min.
  Lincoln Experimental Satellite; communications experiments. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A).

• 1965 May 6 - LES 2 - Launch Site: Cape Canaveral. Launch Complex: LC20. Launch Vehicle: Titan. Mass: 37 kg (81 lb). Perigee: 2,771 km (1,721 mi). Apogee: 14,810 km (9,200 mi). Inclination: 32.20 deg. Period: 309.90 min.
  Experimental commsat. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A).

• 1965 December 21 - LES 4 - Launch Site: Cape Canaveral. Launch Complex: LC41. Launch Vehicle: Titan. Mass: 52 kg (114 lb). Perigee: 189 km (117 mi). Apogee: 33,632 km (20,897 mi). Inclination: 26.60 deg. Period: 589.20 min.
  Lincoln Experimental Satellite; experimental commsat; transmitted in X-band. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A).

• 1965 December 21 - LES 3 - Launch Site: Cape Canaveral. Launch Complex: LC41. Launch Vehicle: Titan. Mass: 16 kg (35 lb). Perigee: 267 km (165 mi). Apogee: 4,829 km (3,000 mi). Inclination: 26.50 deg. Period: 139.90 min.
  Radio signal source for commsat tests. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A).

• 1967 July 1 - LES 5 - Launch Site: Cape Canaveral. Launch Complex: LC41. Launch Vehicle: Titan. Mass: 194 kg (427 lb). Perigee: 33,196 km (20,626 mi). Apogee: 33,609 km (20,883 mi). Inclination: 12.00 deg. Period: 1,316.00 min.
  Experimental commsat. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A).

• 1968 September 26 - LES 6 - Launch Site: Cape Canaveral. Launch Complex: LC41. Launch Vehicle: Titan. Mass: 163 kg (359 lb). Perigee: 35,776 km (22,230 mi). Apogee: 35,839 km (22,269 mi). Inclination: 12.80 deg. Period: 1,437.20 min.
  Experimental commsat. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A). Positioned in geosynchronous orbit over the Atlantic Ocean at 38 deg W in 1968-1975 As of 26 August 2001 located at 61.90 deg W drifting at 0.101 deg E per day. As of 2007 Mar 9 located at 73.59W drifting at 0.201E degrees per day.

• 1976 March 15 - LES 9 - Launch Site: Cape Canaveral. Launch Complex: LC40. Launch Vehicle: Titan. Mass: 454 kg (1,000 lb). Perigee: 35,745 km (22,210 mi). Apogee: 35,825 km (22,260 mi). Inclination: 17.00 deg. Period: 1,436.00 min.
  Spacecraft engaged in practical applications and uses of space technology such as weather or communication. Also tested pulsed plasma engines. Positioned in geosynchronous orbit over the Atlantic Ocean at 30-40 deg W in 1976-78; over the Americas at 90-100 deg W in 1980-81; over the Americas at 100-106 deg W in 1981-1990; over the Atlantic Ocean 10 deg W in 1991; over the Americas at 105 deg W in 1992-on. As of 1 September 2001 located at 103.85 deg W drifting at 0.023 deg W per day. As of 2007 Mar 11 located at 107.07W drifting at 0.018W degrees per day.

• 1976 March 15 - LES 8 - Launch Site: Cape Canaveral. Launch Complex: LC40. Launch Vehicle: Titan. Mass: 454 kg (1,000 lb). Perigee: 35,728 km (22,200 mi). Apogee: 35,835 km (22,266 mi). Inclination: 11.40 deg. Period: 1,435.80 min.
  Spacecraft engaged in practical applications and uses of space technology such as weather or communication. Also tested pulsed plasma engines. Positioned in geosynchronous orbit over the Atlantic Ocean at 1976-77; over the Americas at 106-110 deg W in 1978-1986; over the Atlantic Ocean 60-70 deg W in 1987-1991;over the Americas at 94-106 deg W in 1991-1992. As of 6 September 2001 located at 105.16 deg W drifting at 0.010 deg E per day. As of 2007 Mar 9 located at 107.51W drifting at 0.001E degrees per day.