On 15 February 1996, the Chinese space programme experienced the worst disaster in its history. During its maiden flight, the CZ-3B rocket launcher carrying Intelsat 708 telecommunication satellite began to veer off course only two seconds after lift off, and then hit a hill 1,200m away from the launch pad at T+22 seconds, destroying the US$125 million satellite onboard. The impact and violent explosion of the rocket killed six people and injured another 57, and also destroyed over 80 buildings in a nearby village.
The cause of failure was traced to the launcher’s guidance and control system. A gold-aluminium solder joint in the output of one of the gyro servo loops failed, cutting electrical current output from the power module and causing the inertial reference platform of the vehicle’s guidance and control system to slope. This caused computers to send the vehicle veering off the planned trajectory shortly after lift-off. The failed module was the only one of six similar modules that lacked conductive adhesive to reinforce the solder joint.
The February 1996 was the latest of a long string of launch failures experienced by the Chinese aerospace industry during the 1990s.
On 22 March 1992, a CZ-2E failed to ignite during the launch of an Australian telecommunications satellite Optus B1. When the countdown ended, two of the four main rocket engines of the core vehicle failed to ignite, leading an abort of the launch mission. A disastrous outcome which would have destroyed both the launcher/satellite and launch pad was only narrowly avoided. It then took the ground crew 39 hours to secure the rocket and retrieve the satellite.
On 21 December 1992, another CZ-2E launch failed when the satellite exploded inside the payload fairing only 45 seconds into the ascent, though the rocket launcher continued flying and sent the debris of the satellite into the scheduled orbit. Later investigation suggested that the accident was caused by wind shear.
On 26 January 1995, a CZ-2E rocket carrying another Hughes-built communications satellite APStar 2 exploded approximately 50 seconds into the flight. The failure was believed to have been caused by strong horizontal wind shear once the launch vehicle had cleared the mountains surrounding the launch site. Chinese engineers believed that the wind shear had caused a mechanical resonance that led to an explosion in the satellite’s apogee kick stage, while engineers in Hughes believed that the design flaw in the rocket’s payload fairing led to it collapsing under the force of the wind shear.
On 4 September 1996, the Hong Kong-based Asia Satellite Telecommunications Co, owner of AsiaSat 2, filed an insurance claim of US$58 million for damage to AsiaSat 2 caused by an alleged rough ride during its launch in November 1995 by the CZ-2E. AsiaSat claimed that excessive acceleration caused by the launch vehicle knocked the antenna feed horns of the satellite’s nine Ku-band transponders out of alignment, reducing effective coverage and transmission power to the company’s customers.
These accidents had seriously damaged the reputation of the Chinese aerospace industry, leading to cancellation of many commercial satellite launch contracts. By the late 1990s, the U.S. government imposed a ban of using Chinese launch vehicles for the launch of U.S.-made satellites, or any satellites using U.S.-made components. These two factors eventually forced the Chinese aerospace industry out of the international commercial space launch market by the late 1990s.
