Shenzhou Test Missions (Shenzhou 1/2/3/4)
A total of four unmanned flight tests of the Shenzhou spacecraft vehicle were conducted between November 1999 and January 2003, in order to validate the design and technology of the spacecraft vehicle, its launch vehicle, and the ground support systems. These four mission not only demonstrated a reliable transportation system to send astronauts into orbit and return them back to Earth safely, but also brought the human spaceflight programme (Project 921) previously shrouded in secrecy into the public domain.
The first Shenzhou mission was to fly an experimental test vehicle in order to validate the spacecraft’s design. To meet the 1999 deadline for the first flight test, the mission used a vehicle modified from an electric test article, with only 8 of the 13 onboard sub-systems functional. It did not carry a life-support system, nor can it perform orbit elevation manoeuvre. Its orbital module was only a dummy with no equipment inside.
The launch campaign began with the arrival of the spacecraft vehicle at the Jiuquan Satellite Launch Centre (JSLC) on 26 July 1999, following a three-day train journey from the spacecraft’s fabrication facility in Beijing. The CZ-2F (Y1) launch vehicle was delivered in segments by railway to the launch centre on 18 August. The first all-system launch rehearsal took place on 2 October.
An issue emerged after the vehicle had been assembled, when tests showed that a gyro in the spacecraft’s guidance system had failed. To ratify the issue, the already attached heat shield of the vehicle must be removed, risking causing further damages. After some heated debate among the programme managers, the shield was finally removed to allow the failed gyro to be replaced. The incident caused the launch window to be postponed to 18 November. A Leonid meteor shower then pushed the launch window further back by 48 hours.
The first unmanned Shenzhou test flight mission was finally launched at 06:30 CST on 20 November 1999. Shortly after the first-stage separation, the launch vehicle experienced an abnormal decrease in its velocity. Fortunately, the vehicle soon recovered and continued flying until the payload separation.
More dramas unfolded during the 13th orbit, when the spacecraft vehicle failed to respond to three attempts by the ground control to insert a command for orbit changing prior to re-entry. The last chance to insert the command lied with the Yuanwang 3 tracking ship stationed in Southern Atlantic off the West African coast, with only 47 seconds to spare before the spacecraft flew out of the ship’s horizon. The command was finally inserted with only 10 seconds left.
The re-entry module of the Shenzhou experimental test vehicle landed at 03:41 CST on 21 November, after circling the Earth 14 times. Despite an eventful journey from the start, the mission was nevertheless a success. The spacecraft only carried the name of Shenzhou with no serial number. To differentiate with the subsequent flight missions, this mission was later referred to as Shenzhou 1.
Programme.............Shenzhou (Project 921) Crew..................None Launch vehicle........CZ-2F (Y1) Launch pad............Jiuquan Satellite Launch Centre, Pad 921 Launch date/time......1999-11-20 06:30 CST (1999-11-19 22:30 UTC) Landing date/time.....1999-11-21 03:31 CST (1999-11-20 19:41 UTC) Mission duration......21 h 11 m Orbits................14
The Shenzhou 2 mission was a fully functional prototype of the Shenzhou vehicle with all working sub-systems, though still without the launch escape system. The vehicle carried a total of 64 science experiment packages, including 15 in the re-entry module, 12 in the orbital module, and 37 on the forward external pallet. They included a micro-gravity crystal growing device, a life sciences experiment with 19 species of animals and plants, cosmic ray and particle detectors, and the China’s first gamma ray burst detectors.
The mission was trouble-prone from the start. On 31 December 2000, only days before the scheduled launch, the CZ-2F (Y2) launch vehicle was damaged by an abnormal operation of the umbilical tower. There were serious doubts as whether the rocket was still fit for flying. Following a three-day examination, the launch vehicle was given a greenlight for launch.
The CZ-2F carrying the Shenzhou 2 vehicle lifted off from Jiuquan at 01:11 CST on 10 January 2001 (17:11 UTC on 9 January). About 358 seconds into the launch, both the primary and the backup flight-control computers in the Launch Control Centre crashed, leaving the launch vehicle without control for several minutes. The computers had to be rebooted while the launch vehicle was still flying, and came back online less than 60 seconds before the orbit insertion of the payload. A similar problem then occurred on another computer system shortly after the spacecraft entered orbit.
After orbiting the Earth 117 times, Shenzhou 2 initiated its re-entry sequence on 16 January. However, the harness on the single parachute broke during the descent, resulting in a hard landing of the module at 19:22 CST (11:22 UTC). Although never reported by the Chinese media, the incident was indirectly confirmed by a lack of publicity photographs of the recovered re-entry module after landing.
Programme.............Shenzhou (Project 921) Crew..................None Launch vehicle........CZ-2F (Y2) Launch pad............Jiuquan Satellite Launch Centre, Pad 921 Launch date/time......2001-01-10 01:00:03 CST (2001-01-09 17:00:03 UTC) Landing date/time.....2001-01-16 19:22 CST (2001-01-16 11:22 UTC) Mission duration......6 d 18 h 22 m Orbits................108
The Shenzhou 3 mission was the first fully equipped design with all that would be need for a manned flight, including a fully functioning life support system, an emergency escape system, and a backup parachute on the re-entry module. A dummy capable of simulating human breathing and metabolism was carried inside the re-entry module to test the life support system. Other mission payloads included a cloud imager, a medium-resolution imaging spectrometer, an Earth radiation detector, a solar Ultraviolet spectrum detector, Earth atmosphere probing devices, a crystal growing device, a protein crystallisation experiment, and a gravimetry device.
Shenzhou 3 was originally scheduled to be launched in January 2002, but a defective component was identified on the CZ-2F (Y3) launch vehicle during the final pre-launch check. Upon investigation it transpired that the issue was caused by a design flaw, meaning all other components of the same type on the launch vehicle could also be affected. A total of 73 similar components were found on the vehicle. This led to the decision to remove the launch vehicle from the pad, so that all potentially flawed components could be replaced. This was the first time in the history of China’s space programme that a fully assembled launch vehicle was removed from the launch pad.
Shenzhou 3 was finally launched atop the CZ-2F (Y3) from Jiuquan at 22:15 CST on 25 March 2002 (14:15 UTC). The spacecraft was successfully landed at the Siziwang Banner landing site in Inner Mongolia at 16:51 CST (08:51 UTC) on 1 April 2002, after orbiting the Earth 108 time in six days.
Programme.............Shenzhou (Project 921) Crew..................None Launch vehicle........CZ-2F (Y3) Launch pad............Jiuquan Satellite Launch Centre, Pad 921 Launch date/time......2002-03-25 22:15 CST (2002-03-25 14:15 UTC) Landing date/time.....2001-04-01 16:51 CST (2002-04-01 08:51 UTC) Mission duration......6 d 18 h 51 m Orbits................108
Shenzhou 4 was the fourth and final unmanned test flight before the first manned flight. The spacecraft vehicle was fully functional, identified to that to be used in the manned flight. Compared with previous Shenzhou missions, the vehicle featured a number of modifications which offered extra safety redundancy. For the first time the vehicle was capable of using its own propulsion to escape from the launch vehicle after the launch escape tower and payload fairing were jettisoned. The spacecraft vehicle can then fly automatically to return the crew to Earth within 6 hours. The Shenzhou 4 vehicle was also equipped with a manual flight control, which was independent to the automated flight control. This allowed the mission crew to ‘fly’ the spacecraft in case of a malfunction in the spacecraft’s automated flight control system.
Carried onboard the spacecraft vehicle were two dummy astronauts, which could simulate human activities such as breathing and sweating. The spacecraft vehicle also carried every piece of kit required for a manned flight mission, including space suits, space food, survival kit, sleeping bags, and medications. A total of 52 experiment packages were carried onboard in the field of physics, biology, medicine, earth observation, material science, and astronomy. The experimental multi-mode microwave system, designed for meteorological and oceanographic remote-sensing, was the world’s second space-based microwave remote-sensing system, incorporating three devices: microwave radiometer, radar altimeter, and radar scatterometer. There were also eight sensors designed to monitor the environment in near-Earth space.
Shenzhou 4 was launched atop the CZ-2F (Y4) launch vehicle from Jiuquan at 00:40 CST on 30 December 2002 (16:40 UTC on 29 December). The launch was conducted during the worst snow storm the launch site had ever encountered, with the night temperature dropping to -30°C. The launch crew tried everything they could to keep the fluids inside the launch vehicle and spacecraft from freezing. Fortunately, the low temperature didn’t seem to cause any issue and the launch vehicle flew normally, placing the spacecraft vehicle into its intended orbit.
On 5 January 2003, after orbiting the Earth for 108 times, the spacecraft vehicle initiated the re-entry sequence under the mission control. About 45 minutes later, the re-entry module successfully touched down inside the landing zone in Inner Mongolia, at 19:16 CST (11:169 UTC).
Programme.............Shenzhou (Project 921) Crew..................None Launch vehicle........CZ-2F (Y4) Launch pad............Jiuquan Satellite Launch Centre, Pad 921 Launch date/time......2002-12-30 00:40 CST (2002-12-29 16:40 UTC) Landing date/time.....2003-01-05 19:16 CST (2003-01-05 11:16 UTC) Mission duration......6 d 18 h 36 m Orbits................108