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DSCS II

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DSCS-2 Credit: USAF

AKA: Defense Satellite Communications System. Status: Operational 1971. First Launch: 1971-11-03. Last Launch: 1982-10-30. Number: 15 . Gross mass: 562 kg (1,238 lb). Height: 4.00 m (13.10 ft).

The DSCS system originated in the DoD's Initial Defense Communications Satellite Program, which was inaugurated in 1966. After launching 26 of these spacecraft, the Air Force renamed the program and in 1971 launched the first of 16 DSCS Block II satellites.

The contract was managed by the DCA (Defense Communications Agency) for the USAF. The spacecraft was spin stabilized with a despun antenna platform. Body mounted solar cells produced 535 watts. Three NiCd batteries provided 36 AHr total. A hydrazine propulsion system was used. The payload consisted of two 20 watt X-Band transponders with 500 MHz bandwidths. Steerable narrow beam antennas and drive mechanisms provided a measure of communications privacy. Capacity was 1300 voice channels or 100 Mbps of data. The system was compatible with ground-portable units.

Photo Gallery

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DSCS II-01 Credit: Manufacturer Image

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• Proposals requested fo DSCS II. - . Spacecraft Bus: DSCS. Spacecraft: DSCS II. SAMSO asked qualified contractors to submit proposals for the development of an advanced satellite communications system, the Defense Satellite Communication System Phase II (DSCS II) (Program 777)..

• Contract for six Defense Satellite Communications System Phase II satellites. - . Spacecraft: DSCS II.

  SAMSO awarded a $74 million contract to TRW Systems Group to develop and produce six flight models of an advanced communication satellite for the Defense Satellite Communications System Phase II. Designed to use steerable, narrow-beam antennas to increase performance, the new satellites were intended for use with small surface terminals.

• DSCS II-01 - . Payload: DSCS II F-1 / OPS 9431. Mass: 520 kg (1,140 lb). Nation: USA. Agency: USAF. Program: DSCS. Class: Communications. Type: Military communications satellite. Spacecraft: DSCS II. Completed Operations Date: 1979-05-01 . USAF Sat Cat: 5587 . COSPAR: 1971-095A. Apogee: 35,815 km (22,254 mi). Perigee: 35,765 km (22,223 mi). Inclination: 13.80 deg. Period: 1,436.30 min.

  A Titan IIIC, launched from Cape Canaveral, placed into synchronous orbits the first pair of 1,200-pound advanced communications satellites of the Defense Satellite Communication System Phase II (DSCS II). After some initial difficulties with the satellites, telemetry and command links were established with both satellites by 5 November. Under SAMSO program management, TRW Systems Group manufactured these second generation communications satellites that were intended as replacements for the 26-satellite Initial Defense Satellite Communication Systems (IDSCS). Each of the DSCS II (Program 777) satellites would be able to handle voice, teletype, computerized digital data, and video transmissions. Defense Satellite Communications System. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A). Positioned in geosynchronous orbit over the Americas at 106 deg W in 1972-?; over the Americas at 81 deg W in 1977-1979; over the Americas at 100-110 deg W in drift 1979-1998 As of 1 September 2001 located at 103.05 deg W drifting at 0.044 deg W per day. As of 2007 Mar 9 located at 110.10W drifting at 0.035W degrees per day.

• DSCS II-02 - . Payload: DSCS II F-2 / OPS 9432. Mass: 520 kg (1,140 lb). Nation: USA. Agency: USAF. Program: DSCS. Class: Communications. Type: Military communications satellite. Spacecraft: DSCS II. Completed Operations Date: 1972-01-01 . USAF Sat Cat: 5588 . COSPAR: 1971-095B. Apogee: 35,824 km (22,259 mi). Perigee: 35,819 km (22,256 mi). Inclination: 13.60 deg. Period: 1,437.90 min.

  Defense Satellite Communications System. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A). Positioned in geosynchronous orbit over the Americas at 112 deg W in 1972. As of 30 August 2001 located at 146.34 deg E drifting at 0.101 deg W per day. As of 2007 Mar 5 located at 36.33W drifting at 0.201E degrees per day.

• DSCS II-03 - . Payload: DSCS II F-3 / OPS 9433. Mass: 566 kg (1,247 lb). Nation: USA. Agency: USAF. Program: DSCS. Class: Communications. Type: Military communications satellite. Spacecraft: DSCS II. Completed Operations Date: 1982-08-01 . USAF Sat Cat: 6973 . COSPAR: 1973-100A. Apogee: 36,661 km (22,780 mi). Perigee: 36,413 km (22,625 mi). Inclination: 13.90 deg. Period: 1,474.60 min.

  An Air Force Titan IIIC, launched by the 6555th Aerospace Test Group from the Eastern Test Range, boosted two Program 777 Defense Satellite Communications Systems; 13 deg W. A new inertial guidance system, manufactured by Delco Electronics for the Titan IIIC made its first flight. The new system consisted of an inertial measurement unit and a missile guidance computer. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). Positioned in geosynchronous orbit over the Atlantic Ocean at 13 deg W in 1974-1977; over the Atlantic Ocean 57-66 deg W in 1977-1979 As of 3 September 2001 located at 104.01 deg E drifting at 9.429 deg W per day. As of 2007 Mar 9 located at 148.24W drifting at 9.427W degrees per day.

• DSCS II-04 - . Payload: DSCS II F-4 / OPS 9434. Mass: 566 kg (1,247 lb). Nation: USA. Agency: USAF. Program: DSCS. Class: Communications. Type: Military communications satellite. Spacecraft: DSCS II. Completed Operations Date: 1993-12-20 . USAF Sat Cat: 6974 . COSPAR: 1973-100B. Apogee: 36,837 km (22,889 mi). Perigee: 36,300 km (22,500 mi). Inclination: 13.50 deg. Period: 1,476.30 min.

  Defense Satellite Communications System; 175 deg E. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). Positioned in geosynchronous orbit over the Pacific Ocean at 175 deg E in 1974-1977; over the Indian Ocean 65 deg E in 1977-1980; over the Indian Ocean 60-61 deg E in 1980-1984; over the Indian Ocean 66 deg E in 1984-1987; over the Americas at 56-62 deg W in 1989-1993 As of 5 September 2001 located at 138.02 deg W drifting at 9.919 deg W per day. As of 2007 Mar 3 located at 146.85E drifting at 9.914W degrees per day.

• DSCS II-05 - . Payload: DSCS II F-5 / OPS 9435. Mass: 566 kg (1,247 lb). Nation: USA. Agency: USAF. Program: DSCS. Class: Communications. Type: Military communications satellite. Spacecraft: DSCS II. Decay Date: 1975-05-26 . USAF Sat Cat: 7807 . COSPAR: 1975-040A. Apogee: 256 km (159 mi). Perigee: 160 km (90 mi). Inclination: 28.60 deg. Period: 88.60 min.

  The third pair of Defense Satellite Communications System II satellites was launched; the launch failed due to a malfunction in the Transtage of the Titan IIIC launch vehicle. Unusable orbit. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A).

• DSCS II-06 - . Payload: DSCS II F-6 / OPS 9436. Mass: 566 kg (1,247 lb). Nation: USA. Agency: USAF. Program: DSCS. Class: Communications. Type: Military communications satellite. Spacecraft: DSCS II. Decay Date: 1975-05-26 . USAF Sat Cat: 7808 . COSPAR: 1975-040B. Apogee: 256 km (159 mi). Perigee: 160 km (90 mi). Inclination: 28.60 deg. Period: 88.60 min.

  The third pair of Defense Satellite Communications System II satellites was launched; the launch failed due to a malfunction in the Transtage of the Titan IIIC launch vehicle. Unusable orbit. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A).

• DSCS satellite 9433 failed after 33 months in operation. - . Spacecraft: DSCS II.

• Defense Communications Agency use of NATO IIIB spacecraft - . Spacecraft: NATO 3, DSCS II. A U.S./NATO memorandum of agreement was signed which allowed the Defense Communications Agency the use of the NATO IIIB spacecraft until December 1977. This would supplement the DSCS II satellite coverage..

• Four more DSCS II satellites ordered. - . Spacecraft: DSCS II. SAMSO ordered four more DSCS II satellites from TRW Systems Group. The satellites were ordered through a supplemental agreement attached to the original DSCS II replenishment contract..

• DSCS II-07 - . Payload: DSCS II F-7 / OPS 9437. Mass: 565 kg (1,245 lb). Nation: USA. Agency: USAF. Program: DSCS. Class: Communications. Type: Military communications satellite. Spacecraft: DSCS II. Completed Operations Date: 1981-12-20 . USAF Sat Cat: 10000 . COSPAR: 1977-034A. Apogee: 36,894 km (22,924 mi). Perigee: 36,759 km (22,840 mi). Inclination: 15.80 deg. Period: 1,489.60 min.

  A Titan IIIC launched a pair of DSCS II satellites into orbit from Cape Canaveral, Florida. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). Positioned in geosynchronous orbit over the Atlantic Ocean at 12 deg W in 1977-1979; over the Atlantic Ocean 5 deg W in 1979; over the Pacific Ocean 140 deg E in 1980-1981 As of 28 August 2001 located at 152.07 deg W drifting at 12.959 deg W per day. As of 2007 Mar 10 located at 47.37W drifting at 12.959W degrees per day.

• DSCS II-08 - . Payload: DSCS II F-8 / OPS 9438. Mass: 565 kg (1,245 lb). Nation: USA. Agency: USAF. Program: DSCS. Class: Communications. Type: Military communications satellite. Spacecraft: DSCS II. Completed Operations Date: 1990-02-01 . USAF Sat Cat: 10001 . COSPAR: 1977-034B. Apogee: 37,343 km (23,203 mi). Perigee: 37,061 km (23,028 mi). Inclination: 15.50 deg. Period: 1,509.00 min.

  A Titan IIIC launched a pair of DSCS II satellites into orbit from Cape Canaveral, Florida. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). Positioned in geosynchronous orbit over the Pacific Ocean at 175 deg E in 1977-1979 over the Atlantic Ocean 12 deg W in 1979-80 over the Pacific Ocean 175 deg E in 1980-1983 over the Pacific Ocean180 deg E in 1983-1986 over the Atlantic Ocean 1 deg W in 1986-1989 As of 3 September 2001 located at 143.55 deg W drifting at 17.451 deg W per day. As of 2007 Mar 9 located at 13.13E drifting at 17.445W degrees per day.

• DSCS II-09 - . Payload: DSCS II F-9. Mass: 550 kg (1,210 lb). Nation: USA. Agency: USAF. Program: DSCS. Class: Communications. Type: Military communications satellite. Spacecraft: DSCS II. Decay Date: 1978-03-25 .

  A Titan IIIC was launched from Cape Canaveral carrying DSCS II satellites F-9 and F-10. The vehicle suffered a failure in its second stage hydraulic system about eight minutes after liftoff, and both the vehicle and its payload were lost. Launched with DSCS F10.

• DSCS II F-10 - . Payload: DSCS II F-10. Mass: 562 kg (1,238 lb). Nation: USA. Agency: USAF AFSC. Program: DSCS. Spacecraft: DSCS II. A Titan IIIC was launched from Cape Canaveral carrying DSCS II satellites F-9 and F-10. The vehicle suffered a failure in its second stage hydraulic system about eight minutes after liftoff, and both the vehicle and its payload were lost. .

• Report on Titan IIIC launch failure of 25 March 1978. - . Spacecraft: DSCS II. The AFSC Missile Mishap Investigation Board, investigating the failure of a Titan IIIC launch of DSCS II satellites on 25 March, submitted its final report..

• DSCS III cost overrun - . Spacecraft: DSCS II. General Electric informed SAMSO that there would be a serious cost overrun in the DSCS III program. The contractor estimated that the cost of completing full-scale development would exceed the ceiling.

• DSCS II-11 - . Payload: DSCS II F-11 / OPS 9441. Mass: 550 kg (1,210 lb). Nation: USA. Agency: USAF. Program: DSCS. Class: Communications. Type: Military communications satellite. Spacecraft: DSCS II. Completed Operations Date: 1993-12-13 . USAF Sat Cat: 11144 . COSPAR: 1978-113A. Apogee: 37,749 km (23,456 mi). Perigee: 37,515 km (23,310 mi). Inclination: 9.80 deg. Period: 1,531.40 min.

  A Titan IIIC was launched from Cape Canaveral carrying DSCS II satellites F-ll and F-12. The vehicle placed the satellites in the proper orbit, and the satellites performed normally once there. They were expected to go into operation in mid-January 1979, at which point the DSCS II system would have a full, four-satellite constellation at its disposal for the first time in its history. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). Positioned in geosynchronous orbit over the Pacific Ocean at 135 deg W in 1979-1983 over the Pacific Ocean 129 deg W in 1983-1989 As of 5 September 2001 located at 62.62 deg W drifting at 22.467 deg W per day. As of 2007 Mar 10 located at 96.59E drifting at 22.469W degrees per day.

• DSCS II-12 - . Payload: DSCS II F-12 / OPS 9442. Mass: 550 kg (1,210 lb). Nation: USA. Agency: USAF. Program: DSCS. Class: Communications. Type: Military communications satellite. Spacecraft: DSCS II. Completed Operations Date: 1993-12-13 . USAF Sat Cat: 11145 . COSPAR: 1978-113B. Apogee: 36,332 km (22,575 mi). Perigee: 36,283 km (22,545 mi). Inclination: 9.80 deg. Period: 1,462.80 min.

  Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). Positioned in geosynchronous orbit over the Pacific Ocean at 175 deg E in 1979-1981 over the Indian Ocean 66 deg E in 1981-1983 over the Indian Ocean 60 deg E in 1983-1987 over the Pacific Ocean177 deg E in 1988-1989 over the Indian Ocean 71 deg E in 1990-1992 As of 1 September 2001 located at 93.28 deg E drifting at 6.600 deg W per day. As of 2007 Mar 8 located at 143.60E drifting at 6.589W degrees per day.

• DSCS II space segment at full strength - four operational satellites. - . Spacecraft: DSCS II. DSCS II satellites 9441 and 9442 completed testing and were turned over to the Defense Communications Agency. This brougth the DSCS II space segment up to full strength - four operational satellites..

• DSCS II satellite 9437 lost its #2 narrow coverage high level travelling wave tube amplifier (TWTA). - . Spacecraft: DSCS II. Since the #1 narrow coverage high level TWTA had already failed, the satellite became unable to provide narrow coverage communications support and had to be placed in on-orbit storage..

• DSCS II-13 - . Payload: DSCS II F-13 / OPS 9443. Mass: 611 kg (1,347 lb). Nation: USA. Agency: USAF. Program: DSCS. Class: Communications. Type: Military communications satellite. Spacecraft: DSCS II. Completed Operations Date: 1994-07-19 . USAF Sat Cat: 11621 . COSPAR: 1979-098A. Apogee: 37,195 km (23,111 mi). Perigee: 37,104 km (23,055 mi). Inclination: 13.60 deg. Period: 1,506.30 min.

  Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). Positioned in geosynchronous orbit at 12 deg W in 1980-1981; 131 deg W in 1981-1983; 179 deg W in 1983; 175 deg E in 1983-1989;179 deg W in 1989-1993 As of 3 September 2001 located at 21.08 deg E drifting at 16.828 deg W per day. As of 2007 Mar 10 located at 37.50W drifting at 16.828W degrees per day.

• DSCS II-14 - . Payload: DSCS II F-14 / OPS 9444. Mass: 611 kg (1,347 lb). Nation: USA. Agency: USAF. Program: DSCS. Class: Communications. Type: Military communications satellite. Spacecraft: DSCS II. Completed Operations Date: 1995-06-19 . USAF Sat Cat: 11622 . COSPAR: 1979-098B. Apogee: 36,351 km (22,587 mi). Perigee: 36,316 km (22,565 mi). Inclination: 13.30 deg. Period: 1,464.10 min.

  Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). Positioned in geosynchronous orbit at 66 deg E in 1980-1981; 12 deg W in 1981-1986; 179 deg W in 1986-1990; 174 deg E in 1990; 65 deg E in 1991-1994 As of 31 August 2001 located at 27.01 deg W drifting at 6.916 deg W per day. As of 2007 Mar 11 located at 50.79E drifting at 6.926W degrees per day.

• DSCS II-15 - . Payload: DSCS II F-15. Mass: 562 kg (1,238 lb). Nation: USA. Agency: USAF. Program: DSCS. Class: Communications. Type: Military communications satellite. Spacecraft: DSCS II. Completed Operations Date: 1997-05-23 . USAF Sat Cat: 13636 . COSPAR: 1982-106A. Apogee: 37,332 km (23,196 mi). Perigee: 37,277 km (23,162 mi). Inclination: 11.30 deg. Period: 1,514.40 min.

  Positioned in geosynchronous orbit at 15 deg W in 1983-1987; 66 deg E in 1987; 60 deg E in 1987-1994; 65 deg E in 1994-1997 As of 5 September 2001 located at 114.00 deg W drifting at 18.661 deg W per day. As of 2007 Mar 9 located at 172.94E drifting at 18.658W degrees per day. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C).