FIRST COMMUNICATIONS SATELLITES

The new Long March 3 and its payload made their way to the pad on New Year’s Day, 1984. Three rockets had been allocated to the task in recognition that success

might not come on the first attempt. Wisps of evaporating oxidizer blew away from the third stage as the rocket counted down. All seemed to go perfectly at first, the upper stage with Shiyan Weixing entering its parking orbit of 290-460 km, 31°. It was intended that the third stage would fire a second time over Xi Chang on its first pass so as to shoot the satellite on its way to geosynchronous orbit – but the engine failed, leaving the satellite stranded in low Earth orbit. Pressure in the launching chamber reached only 90% of the level necessary and, after 3 sec, collapsed. A turbine had overheated, so analysis of downlink to the tracking ship Yuan Wang 1 revealed.

This was a great disappointment, for the YF-73 had been exhaustively tested. The Chinese decided they would salvage what they could of the Shiyan Weixing, simulating the final maneuvers, station-keeping, and testing the communications and engineering systems. Engineers worked night and day to resolve the problems and get the next test ready before summer rain and thunder made launches more difficult. The new satellite was called Shiyan Tongbu Tongxin Weixing (experimental geostationary communications satellite). The Yuan Wang again took up position 1,000 km off the Chinese coast. At dusk on 8th April, the clouds rolled away and twinkling stars came out in the darkening sky. Spotlights played on the ready rocket. Fuelling began and crowds began to gather on the surrounding hills. At 19:20:02, a technician pressed the red firing button and the Long March 3 headed skyward. As the Long March 3 upper stage cruised southbound over the Earth’s equator, the rocket reignited and hurtled the 1-tonne satellite skyward. Twenty minutes later, Yuan Wang reported that, this time, the burn to geosynchronous orbit appeared to be alright, at 437-35,499 km, 31.08°. Two days later, the apogee kick motor fired to raise the perigee to 35,521 km and the apogee to 36,383 km, bringing the inclination to less than 1°, hovering over 125°E.

The final test came on 16th April when the television relay system was commanded on. The first pictures were clear and stable, the colors realistic, and the sound well up to standard. The satellite hosted 200 telephone lines – many to the remote west of the country – and, in a much-publicized phone call, a senior official in the Communist Party called a distant party committee in Xinjiang. The voice quality was good, with almost no background noise or interference. Its 15 radio and television channels transmitted programs in Cantonese, Amoy, Hakka, Japanese, Spanish, Russian, Burmese, and Tagalog, some of these languages not hitherto familiar on the international satellite ether. The satellite operated for four years, correcting its orbit every two months, and retired into a graveyard orbit in 1988. To mark the success of the new satellite, a solemn celebration was convened in the Great Hall of the People, in Beijing.

Following the success of Shiyan Tongbu Tongxin Weixing, the Chinese proceeded to the launch of the first operational geosynchronous communications satellite, Shiyong Tongbu Tongxin Weixing (“operational geostationary communications satellite”). The main difference was an improved 0.7-m-diameter dish and it was launched two years later, operating for four years and transmitting 30 television stations.