Encyclopedia Astronautica
DFH-2



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DFH-2
dfh2.jpg
DFH-2
Chinese military communications satellite. 7 launches, 1984.01.29 (STTW-T1) to 1991.12.28 (Zhongxing-4). The DFH-2 was a spin-stabilized, drum-shaped military communications satellite with a despun antenna, a diameter of 2.1 m, and a height of 3.1 m.

The communications payload consisted of only two C-band 6/4 GHz transponders, each having a saturated power output 7.3 dBW (10 W).

The global coverage horn antenna had a receive/transmit gain of 19.5 dB/16.5 dB, using circular polarization. The total electrical power capacity was 300 W. Also known as STW-1, the satellites were the technological equivalent of the 1960's Intelsat-3 and used a solid apogee kick motor to insert the satellites into geostationary orbit. Design life was four years, mass including the apogee kick motor propellant was about 900 kg and on-orbit mass was 441 kg. Two prototypes had an on-orbit mass of 433 kg and power of 284 W. The improved version DFH-2A was similar to DFH-2, but had four C-band transponders, and more precise position and attitude controls. China successfully launched three DFH-2A's (STW-3 on March 7, 1988, STW-4 on December 22, 1988, STW-55 on February 4, 1990). They were used for both military and domestic satellite telecommunication services and television broadcast program distribution.

AKA: Shiyong Tongbu Tongxin Weixing; STTW; STW-1.
Gross mass: 1,025 kg (2,259 lb).
Unfuelled mass: 441 kg (972 lb).
Height: 3.10 m (10.10 ft).
First Launch: 1984.01.29.
Last Launch: 1991.12.28.
Number: 7 .

More... - Chronology...


Associated Countries
Associated Engines
  • DFH-2 AKM Fourth Academy solid rocket engine. 43.460 kN. DFH series apogee kick motor. Out of Production. Isp=287s. First flight 1984. First use in China of glass fibre wound cases, carbon/carbon nozzle throat insert material, contoured divergent nozzle. More...

See also
  • CZ China's first ICBM, the DF-5, first flew in 1971. It was a two-stage storable-propellant rocket in the same class as the American Titan, the Russian R-36, or the European Ariane. The DF-5 spawned a long series of Long March ("Chang Zheng") CZ-2, CZ-3, and CZ-4 launch vehicles. These used cryogenic engines for upper stages and liquid-propellant strap-on motors to create a family of 12 Long-March rocket configurations capable of placing up to 9,200 kg into orbit. In 2000 China began development of a new generation of expendable launch vehicles using non-toxic, high-performance propellants with supposedly lower operating costs. However these encountered development delays, and it seemed the reliable Long March series of rockets would continue in operational use for nearly fifty years before being replaced. More...

Associated Launch Vehicles
  • CZ Chinese orbital launch vehicle. China's first ICBM, the DF-5, first flew in 1971. It was a two-stage storable-propellant rocket in the same class as the American Titan, the Russian R-36, or the European Ariane. The DF-5 spawned a long series of Long March ("Chang Zheng") CZ-2, CZ-3, and CZ-4 launch vehicles. These used cryogenic engines for upper stages and liquid-propellant strap-on motors to create a family of 12 Long-March rocket configurations capable of placing up to 9,200 kg into orbit. In 2000 China began development of a new generation of expendable launch vehicles using non-toxic, high-performance propellants with supposedly lower operating costs. However these encountered development delays, and it seemed the reliable Long March series of rockets would continue in operational use for nearly fifty years before being replaced. More...
  • CZ-3 Chinese orbital launch vehicle. The Long March 3 was a three-stage launch vehicle designed for delivery of satellites of 1,500 kg mass into geosynchronous transfer orbit. The first and second stages were based on the CZ-2C, and designed and manufactured by the Shanghai Academy of Spaceflight Technology. The majority of the technology and flight hardware used in the CZ-3 had been qualified and proven on the CZ-2C. The third stage, manufactured by CALT, was equipped with an LOX/LH2 cryogenic engine. Long March 3 was also capable of placing spacecraft into an elliptical or circular low earth orbit and sun synchronous orbit. More...

Associated Manufacturers and Agencies
  • Chinasat Chinese agency overseeing development of spacecraft. Chinasat, China. More...

Associated Propellants
  • Solid Solid propellants have the fuel and oxidiser embedded in a rubbery matrix. They were developed to a high degree of perfection in the United States in the 1950's and 1960's. In Russia, development was slower, due to a lack of technical leadership in the area and rail handling problems. Solid propellants have the fuel and oxidiser embedded in a rubbery matrix. They were developed to a high degree of perfection in the United States in the 1950's and 1960's. In Russia, development was slower, due to a lack of technical leadership in the area and rail handling problems. More...

Bibliography
  • McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: here.
  • JPL Mission and Spacecraft Library, Jet Propulsion Laboratory, 1997. Web Address when accessed: here.
  • Johnson, Nicholas L; and Rodvold, David M, Europe and Asia in Space 1993-1994, USAF Phillips Laboratory, Kirtland AFB, NM 80907, 1995..
  • McDowell, Jonathan, Launch Log, October 1998. Web Address when accessed: here.
  • Wen-Rui Hu, Editor, Space Science in China, Gordon and Breach Science Publishers, China, 1997..

Associated Launch Sites
  • Xichang China's launch site for geosynchronous orbit launches. Xichang Satellite Launch Centre is situated in Xichang, Sichuan Province, south-western China. The launch pad is at 102.0 degrees East and 28.2 degrees North. The head office of the launch centre is located in Xichang City, about 65 kilometers away. Xichang Airport is 50 km away. A dedicated railway and highway lead directly to the launch site. More...

DFH-2 Chronology


1984 January 29 - . 12:25 GMT - . Launch Site: Xichang. Launch Complex: Xichang LC1. LV Family: CZ. Launch Vehicle: CZ-3. LV Configuration: Chang Zheng 3 CZ3-1 (9). FAILURE: Third stage failed to ignite.. Failed Stage: 3.
  • STTW-T1 - . Payload: STTW-T1. Mass: 900 kg (1,980 lb). Nation: China. Agency: MAI. Class: Communications. Type: Civilian communications satellite. Spacecraft: DFH-2. USAF Sat Cat: 14670 . COSPAR: 1984-008A. Apogee: 6,446 km (4,005 mi). Perigee: 484 km (300 mi). Inclination: 36.1000 deg. Period: 162.00 min. Summary: First launch of a prototype DFH-2 communications satellite. Payload stranded in low earth orbit, but all subsystems including the communications payload were completely checked and tested..

1984 April 8 - . 11:20 GMT - . Launch Site: Xichang. Launch Complex: Xichang LC1. LV Family: CZ. Launch Vehicle: CZ-3. LV Configuration: Chang Zheng 3 CZ3-2 (10).
  • STTW-T2 - . Payload: STTW-T2. Mass: 900 kg (1,980 lb). Nation: China. Agency: MAI. Class: Communications. Type: Civilian communications satellite. Spacecraft: DFH-2. Completed Operations Date: 1988-06-28 . USAF Sat Cat: 14899 . COSPAR: 1984-035A. Apogee: 35,796 km (22,242 mi). Perigee: 35,733 km (22,203 mi). Inclination: 6.1000 deg. Period: 1,435.00 min. Prototype of DFH-2 communications satellite. After on-orbit testing and check out of the satellite and the ground stations, the satellite system was declared operational, and was used experimentally for the transmission of television, telephone, and data messages with good results. It stayed in operation for more than four years, exceeding the design life of three years by a comfortable margin. Operated in geosynchronous orbit at 125 deg E in 1984-1988. As of 4 September 2001 located at 40.81 deg E drifting at 0.320 deg W per day. As of 2007 Feb 27 located at 133.57E drifting at 0.079W degrees per day.

1986 February 1 - . 12:37 GMT - . Launch Site: Xichang. Launch Complex: Xichang LC1. LV Family: CZ. Launch Vehicle: CZ-3. LV Configuration: Chang Zheng 3 CZ3-3 (13).
  • STTW 1 - . Payload: STTW 1. Mass: 1,024 kg (2,257 lb). Nation: China. Agency: MAI. Class: Communications. Type: Civilian communications satellite. Spacecraft: DFH-2. Completed Operations Date: 1990-06-01 . USAF Sat Cat: 16526 . COSPAR: 1986-010A. Apogee: 35,819 km (22,256 mi). Perigee: 35,774 km (22,228 mi). Inclination: 9.8000 deg. Period: 1,436.60 min. Second successful DFH-2 launch. Also designated STW-2, the satellite was positioned at 103 deg E. In comparison to the first two DFH-2's, a parabolic antenna reflector replaced the horn antenna. Operated in geosynchronous orbit at 103 deg E in 1986-1990. As of 3 September 2001 located at 102.75 deg E drifting at 0.030 deg W per day. As of 2007 Mar 10 located at 46.50E drifting at 0.019E degrees per day.

1988 March 7 - . 12:41 GMT - . Launch Site: Xichang. Launch Complex: Xichang LC1. LV Family: CZ. Launch Vehicle: CZ-3. LV Configuration: Chang Zheng 3 CZ3-4 (17).
  • Zhongxing-1 - . Payload: STTW 2. Mass: 1,024 kg (2,257 lb). Nation: China. Agency: Chinasat. Class: Communications. Type: Military communications satellite. Spacecraft: DFH-2. Completed Operations Date: 1997-07-01 . USAF Sat Cat: 18922 . COSPAR: 1988-014A. Apogee: 35,789 km (22,238 mi). Perigee: 35,786 km (22,236 mi). Inclination: 0.5000 deg. Period: 1,436.20 min. Summary: Operated in geosynchronous orbit at 87 deg E in 1988-1997. As of 28 August 2001 located at 87.94 deg E drifting at 0.038 deg E per day. As of 2007 Mar 11 located at 64.00E drifting at 0.067E degrees per day..

1988 December 22 - . 12:40 GMT - . Launch Site: Xichang. Launch Complex: Xichang LC1. LV Family: CZ. Launch Vehicle: CZ-3. LV Configuration: Chang Zheng 3 CZ3-5 (20).
  • Zhongxing-2 - . Payload: STTW 3. Mass: 1,024 kg (2,257 lb). Nation: China. Agency: Chinasat. Class: Communications. Type: Military communications satellite. Spacecraft: DFH-2. USAF Sat Cat: 19710 . COSPAR: 1988-111A. Apogee: 35,791 km (22,239 mi). Perigee: 35,787 km (22,236 mi). Inclination: 0.1000 deg. Period: 1,436.20 min. Summary: Operated in geosynchronous orbit at 110 deg E in 1989-1999. As of 27 August 2001 located at 91.92 deg E drifting at 0.244 deg E per day. As of 2007 Mar 10 located at 83.40E drifting at 0.283W degrees per day..

1990 February 4 - . 12:28 GMT - . Launch Site: Xichang. Launch Complex: Xichang LC1. LV Family: CZ. Launch Vehicle: CZ-3. LV Configuration: Chang Zheng 3 CZ3-6 (21).
  • Zhongxing-3 - . Payload: STTW 4. Mass: 1,024 kg (2,257 lb). Nation: China. Agency: Chinasat. Class: Communications. Type: Military communications satellite. Spacecraft: DFH-2. Completed Operations Date: 1998-07-01 . USAF Sat Cat: 20473 . COSPAR: 1990-011A. Apogee: 35,795 km (22,241 mi). Perigee: 35,783 km (22,234 mi). Inclination: 0.0000 deg. Period: 1,436.30 min. National operational communications satellite. Designation 1990-2. Operated in geosynchronous orbit at 98 deg E in 1990-1998. As of 4 September 2001 located at 52.36 deg E drifting at 0.045 deg W per day. As of 2007 Mar 10 located at 96.88E drifting at 0.061W degrees per day.

1991 December 28 - . 12:00 GMT - . Launch Site: Xichang. Launch Complex: Xichang LC1. LV Family: CZ. Launch Vehicle: CZ-3. LV Configuration: Chang Zheng 3 CZ3-8 (26). FAILURE: Third stage failed to ignite. Partial Failure.. Failed Stage: 3.
  • Zhongxing-4 - . Payload: STTW 5. Mass: 1,025 kg (2,259 lb). Nation: China. Agency: Chinasat. Program: Chinasat. Class: Communications. Type: Military communications satellite. Spacecraft: DFH-2. USAF Sat Cat: 21833 . COSPAR: 1991-088A. Apogee: 34,041 km (21,152 mi). Perigee: 2,023 km (1,257 mi). Inclination: 32.3000 deg. Period: 632.60 min. Summary: Third stage failure; unusable orbit. DFH-2 operational communications satellite..

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