TACSAT

Encouraged by the success of the Syncom DSCS I and LES experiments the US DoD deployed a large 730-kg satellite designed for UHF tactical use. TACSAT-1 was launched by a Titan-3C on 9 February 1969 into a synchronous orbit at 180 W to provide one high-capacity transponder in X-band and one transponder to support mobile users in UHF to man-pack terminals for the first time, utilizing an array of five 2.5-m antennas. The 30-W X-band transponder and the 230-W UHF transponder each had a bandwidth of 10 MHz (transmit frequency: 249.6 MHz and receive: 303.4 MHz and 307.5 MHz). The satellite was spin-stabilized with body-mounted solar cells generating 980W recharging three NiCd batteries. Cross strapping between the UHF and X-band uplinks and downlinks was available with a reduced usable bandwidth of 425 kHz. TACSAT-1 was shut down after an attitude control failure in 1972.