Encyclopedia entry

Syncom

Spacecraft · USA

Part of HS 301

Original archive entry. The text, images and links below are kept as they were written.

American communications technology satellite. Experimental telecommunications satellite. Communication satellite built by Hughes for NASA, USA. Launched 1963 - 1964. Used the HS-301 bus.

More at: Syncom.

Family: Communications technology sat, Geosynchronous orbit, Technology
Country: USA
Engines: Star 13D
Launch Vehicles: Thor, Delta, Thor Delta B, Thor Delta D
Launch Sites: Cape Canaveral, Cape Canaveral LC17B, Cape Canaveral LC17A
Agency: NASA
Bibliography: 2, 279, 4135, 4136, 4137, 4138, 4139, 4140, 4141, 4142, 4143, 4144, 4145, 4146, 4147, 4148, 4149, 6, 6964, 13245

Photo Gallery

Syncom I; Syncom 1
Credit: Manufacturer Image
STS-41-D
Deployment of the Syncom IV (Leasat-2) satellite
Credit: NASA
STS-41-D
View of the Syncom IV satellite in orbit over the earth
Credit: NASA
STS-51-A
Syncom IV-1 satellite leaving Discovery's payload bay
Credit: NASA
STS-51-D
End effector of the Discovery's RMS with tools moves toward Syncom-IV
Credit: NASA
STS-51-D
Syncom-IV (LEASAT) satellite
Credit: NASA
STS-51-I
Astronaut James van Hoften on RMS tracking Syncom IV-3 after deployment
Credit: NASA
STS-51-I
Astronaut James van Hoften working with Syncom IV-3 satellite
Credit: NASA
STS-51-I
Astronaut James van Hoften working with Syncom IV-3 satellite
Credit: NASA
STS-51-I
Astronaut James van Hoften working with Syncom IV-3 satellite
Credit: NASA
STS-32
SYNCOM IV-5 satellite drifts over cloud-covered Earth after STS-32 deployment
Credit: NASA

Chronology

6 events

1963 February 14

05:35 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC17B. LV Family: Thor. Launch Vehicle: Thor Delta B.

Syncom 1 - . Payload: Syncom 1. Mass: 39 kg (85 lb). Nation: USA. Agency: NASA Greenbelt. Class: Technology. Type: Communications technology satellite. Spacecraft Bus: HS 301. Spacecraft: Syncom. Completed Operations Date: 1963-02-14 . USAF Sat Cat: 553 . COSPAR: 1963-004A. Apogee: 36,739 km (22,828 mi). Perigee: 34,392 km (21,370 mi). Inclination: 33.30 deg. Period: 1,425.50 min.
During firing of the apogee kick motor, contact was lost with the satellite. Syncom (Synchronous Communications) was a NASA project supported by DoD ground stations and communications experiments. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). Four score. Last known longitude (10 March 1987) 172.58 deg E drifting at 2.429 deg E per day.

1963 July 26

14:33 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC17A. LV Family: Thor. Launch Vehicle: Thor Delta B.

Syncom 2 - . Mass: 39 kg (85 lb). Nation: USA. Agency: NASA Greenbelt. Class: Technology. Type: Communications technology satellite. Spacecraft Bus: HS 301. Spacecraft: Syncom. Completed Operations Date: 1969-04-01 . USAF Sat Cat: 634 . COSPAR: 1963-031A. Apogee: 35,891 km (22,301 mi). Perigee: 35,891 km (22,301 mi). Inclination: 32.70 deg. Period: 1,441.50 min.
NASA's Syncom II synchronous communications satellite was placed in orbit by a Thor/Delta launched from Cape Canaveral. Experimental commsat; first geosynchronous satellite. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). Positioned in geosynchronous orbit at 55 deg W in 1963; 26 deg W in 1965. Last known longitude (19 July 1995) 68.47 deg E drifting at 0.089 deg W per day.

1964 August 19

12:15 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC17A. LV Family: Thor. Launch Vehicle: Thor Delta D.

Syncom 3 - . Payload: Syncom C. Mass: 39 kg (85 lb). Nation: USA. Agency: NASA Greenbelt. Class: Technology. Type: Communications technology satellite. Spacecraft Bus: HS 301. Spacecraft: Syncom. Completed Operations Date: 1974-12-29 . USAF Sat Cat: 858 . COSPAR: 1964-047A. Apogee: 35,792 km (22,240 mi). Perigee: 35,784 km (22,235 mi). Inclination: 0.10 deg. Period: 1,436.20 min.
NASA's Syncom III synchronous communications satellite was launched into orbit by a Thrust Augmented Thor/Delta (TAD) launch vehicle in its first use as a space booster. Also carried Star Flash experiment. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). Positioned in geosynchronous orbit at 64 deg W in 1964; 180 deg E in 1964; 25 deg W in 1965; 165 deg E in 1966-1969. Last known longitude (6 December 1974) 6.08 deg W drifting at 0.188 deg W per day.

1964 Sep

Syncom used for military communications with Vietnam. - . Spacecraft Bus: HS 301. Spacecraft: Syncom.
The Defense Department began military communications experiments between Saigon, Republic of South Vietnam, and Hawaii using the Syncom II synchronous communications satellite. These Saigon-Hawaii experiments further extended the Defense Department's usage of Syncom II that had begun several months earlier.

1965 January 1

Syncom 2 and 3 to be transferred to the US Defense Department. - . Spacecraft Bus: HS 301. Spacecraft: Syncom. NASA transferred the operation of Syncom II and Syncom III synchronous communications satellites to the Defense Department which had provided the communications ground stations for the program..

1965 July 8

Transfer of Syncom 2 and 3 from NASA to the Defense Department completed. - . Spacecraft Bus: HS 301. Spacecraft: Syncom.
The transfer of Syncom II and III from NASA to the Defense Department was completed. The Defense Communications Agency (DCA) directed their use, but the Air Force Satellite Control (AFSCF) and its operating locations in the Pacific and Indian Oceans maintained precise control and positioning of the two synchronous communications satellites. The Army and Navy were responsible for the ground communications facilities that were used with the Syncom satellites.