Encyclopedia Astronautica
TACSAT



tacsat.jpg
Tacsat
Credit: USAF
American communications technology satellite. First launch 1969.02.09. TACSAT was designed to experimentally test and develop tactical communications concepts for all US military services.

As part of an Air Force program aimed at eventual development of a military tactical communications system to complement the IDCSP system, Hughes built the largest experimental communications satellite ever constructed to that time. The mission evaluated the feasibility of using satellite communication repeaters with small surface terminal communication equipment for highly mobile land, sea and air forces. The project was led by the USAF Space and Missile Systems Organization (SAMSO). The satellite featured a then-unique antenna array extending from the top of the drum-shaped spacecraft. The five-element antenna array consisted of UHF antennas, each nearly 2.5 m long. Beneath them were 2 microwave horns. At the extreme top was a biconical horn used for telemetry and command. Technology and concepts originating in this satellite would later make Hughes the leader in commercial communications satellites.

The satellite was spin-stabilized, with the solar panels rotating while the antennas and inner structure remain in a fixed position. The spacecraft was a cylindrical shaped aluminum structure with passive thermal control, spin stabilized (54 rpm) to 0.1 deg using a new gyrostat technique. Body mounted solar cells generated 980 W max and recharged three NiCd batteries of 6 AHr capacity each. The vehicle carried two transponders, one at X-band and one at UHF. The X-band transponder had a bandwidth of 10 Mhz and a maximum RF power of 30 watts. The UHF transponder had a bandwidth of 10 Mhz and a maximum RF output of 230 watts. Provision was made for cross strapping the UHF and X-band up and downlinks with a reduced usable bandwidth of 425 kHz. Earth coverage horn antennas were used at X-band, bifilar helices were used at UHF.

Gross mass: 730 kg (1,600 lb).
Height: 3.40 m (11.10 ft).
First Launch: 1969.02.09.
Last Launch: 2009.05.19.
Number: 2 .

More... - Chronology...


Associated Countries
See also
  • Titan The Titan launch vehicle family was developed by the United States Air Force to meet its medium lift requirements in the 1960's. The designs finally put into production were derived from the Titan II ICBM. Titan outlived the competing NASA Saturn I launch vehicle and the Space Shuttle for military launches. It was finally replaced by the USAF's EELV boosters, the Atlas V and Delta IV. Although conceived as a low-cost, quick-reaction system, Titan was not successful as a commercial launch vehicle. Air Force requirements growth over the years drove its costs up - the Ariane using similar technology provided lower-cost access to space. More...

Associated Launch Vehicles
  • Titan American orbital launch vehicle. The Titan launch vehicle family was developed by the United States Air Force to meet its medium lift requirements in the 1960's. The designs finally put into production were derived from the Titan II ICBM. Titan outlived the competing NASA Saturn I launch vehicle and the Space Shuttle for military launches. It was finally replaced by the USAF's EELV boosters, the Atlas V and Delta IV. Although conceived as a low-cost, quick-reaction system, Titan was not successful as a commercial launch vehicle. Air Force requirements growth over the years drove its costs up - the Ariane using similar technology provided lower-cost access to space. More...
  • Titan 3C American orbital launch vehicle. Titan 3A with five segment solid motors. Man-rated design originally developed for Dynasoar spaceplane. More...

Associated Manufacturers and Agencies
  • USAF SAMSO American agency overseeing development of spacecraft. Space and Missile Systems Organization, USA. More...
  • Hughes American manufacturer of rockets, spacecraft, and rocket engines. Hughes Aircraft Co. , USA 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.
  • Aerospace Yearbook, 1966,

Associated Launch Sites
  • Cape Canaveral America's largest launch center, used for all manned launches. Today only six of the 40 launch complexes built here remain in use. Located at or near Cape Canaveral are the Kennedy Space Center on Merritt Island, used by NASA for Saturn V and Space Shuttle launches; Patrick AFB on Cape Canaveral itself, operated the US Department of Defense and handling most other launches; the commercial Spaceport Florida; the air-launched launch vehicle and missile Drop Zone off Mayport, Florida, located at 29.00 N 79.00 W, and an offshore submarine-launched ballistic missile launch area. All of these take advantage of the extensive down-range tracking facilities that once extended from the Cape, through the Caribbean, South Atlantic, and to South Africa and the Indian Ocean. More...
  • Cape Canaveral LC41 Titan, Atlas V launch complex. Complexes 40 and 41 were constructed as part of the Integrate-Transfer-Launch (ITL) Titan launch facility at the north end of Cape Canaveral in the early 1960s. Over the next three decades, the complexes supported a wide variety of military space missions involving Titan IIIC, Titan 34D and Titan IV. Complex 41 was deactivated at the end of 1977, then upgraded for the Titan IV program in the 1986-88 period. In October 1999, Complex 41 was demolished with high explosives in order for a new pad for launch of the Atlas 5 rocket to be erected. By then it had been the starting point for 27 Titan flights. More...

TACSAT Chronology


1969 February 9 - . 21:09 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC41. LV Family: Titan. Launch Vehicle: Titan 3C. LV Configuration: Titan IIIC 3C-17.
  • Tacsat 1 - . Mass: 730 kg (1,600 lb). Nation: USA. Agency: USAF. Class: Technology. Type: Communications technology satellite. Spacecraft: Tacsat. Completed Operations Date: 1977-01-01 . USAF Sat Cat: 3691 . COSPAR: 1969-013A. Apogee: 36,044 km (22,396 mi). Perigee: 35,939 km (22,331 mi). Inclination: 1.0000 deg. Period: 1,446.60 min. Experimental commsat. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A). Positioned in geosynchronous orbit over the Americas at 107 deg W in 1969?-1970; over the Pacific Ocean 173 deg W in 1970; over the Pacific Ocean 179 deg W in 1971-1972; over the Pacific Ocean170 deg E in 1972 Last known longitude (9 June 1995) 176.44 deg E drifting at 0.150 deg E per day.

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