SHENZHOU 2: HARD LANDING?

The second Shenzhou mission had originally been set for October 2000, but delays pushed preparations to 5th January the following year. Wintertime was favored because seas were at their calmest in the southern seas where the tracking ships were located. On New Year’s Eve, a crane hit and dented the second stage of the launcher, causing a five-day delay. It was not until the early hours of 10th January 2001 that Shenzhou 2 lifted off from Jiuquan. Shenzhou 2 entered orbit as it passed over the Chinese coast in a path that circled the Earth every 91.1 min at 197-336 km, 42.58°. A ground observer in Houston, Texas, spotted Shenzhou through binoculars six hours later. It was at a magnitude of +2 to +3.5 and could just be seen with the naked eye.

This time, it was a fully functioning version. Twelve experiments were carried on the orbital module, 15 in the descent module and 37 in a scientific unit both inside and attached to the orbital module on the outside – 64 experiments in all. Each Shenzhou from now on was kitted out with a different set of instruments in, on the outside of, and on the front of the orbital module. There were 25 life science experiments, selected from 87 proposals to the Academy of Sciences. Ten biological experiments were flown, including micro-organisms, plants, aquatic organisms, larvae, and invertebrates. The Chinese announced that animals were on board, along with a cargo of plants, seeds, and snails. The exact nature of the animals was not revealed – one newspaper quoted a dog, a monkey, and a rabbit, another rats; there was even a report of a snake (some wit volunteered “a panda”). Post-landing announcements gave the cargoes as six mice, fruit flies, and small aquatic animals. The specimens were chosen by the Institute of Medical Space Engineering. There were three containers with 20,000 plant grains and seeds, including tomato, cucumber, cabbage, Chinese cabbage, wheat, potato, com, apple, pear, asparagus, carrot, and fungus. Other experiments dealt with life sciences, astronomy, physics, materials sciences, semiconductors, oxide crystals, the crystal growth of protein and biological macromolecules in zero gravity, and the effects of the space environment on cells and micro-organisms. There was a multi-chamber crystal growth furnace for semiconductors, oxidized mono-crystals, and metallic alloys, photographed by camera. Experiments covered molecular biology, crystal oxides, metal alloys, atmospheric density, astrophysics, and solar physics.

Shenzhou relayed television from the descent cabin: in the course of time, this would send back pictures of the first yuhangyuan on board. Shenzhou 2 carried, unlike its predecessor, the full environmental control system to provide air and proper temperatures for a crew. A second advance was that Shenzhou 2 tested the spacecraft’s maneuvering ability. At 13:23 on the 10th, 20 hr 20 min into its mission and off the coast of Namibia, Shenzhou 2 raised its low point to adjust its orbit to a more circular path of 329-334 km, one of the main objectives of the mission. On

12th January at 12:19, there was a small maneuver to re-estabhsh the orbit from decay. At 10:34 on 15th January, Shenzhou 2 adjusted its course over the Arabian Sea to an apogee of 345 km, so as to get on track for re-entry the following day. The orbital module was cast free at 10:23 on 16th January as it was passing over 42.5°W, 64.7°S. Retro-fire duly took place 10 min later over 34.2°S, 7.3°W, off the coast of south-west Africa and over Yuan Wang 3.

Shenzhou passed over Tanzania, Somalia, the coastline of Saudi Arabia, and Pakistan, eventually passing over the Jiuquan launch site to come down over Inner Mongolia. In the recovery zone, darkness had fallen. The recovery team, equipped with four helicopters and six recovery vehicles, was ready in perishingly cold conditions, with temperatures tumbling to -30°C. Far to the west, the fireball of Shenzhou 2’s re-entry was spotted as the spacecraft went into the blackout zone. There were cheers when the first radar station picked up the cabin high in the atmosphere. The drogue parachute came out under 20 km and then the 1,200-m2 main parachute. As the cabin touched down, the circling helicopters saw the brown and orange flash of the landing rockets in the dark and headed towards the spot. It was a bitter evening during one of the coldest winters for many years. Total flight time was 6 days, 18 hr 21 min and the cabin had made 108 orbits and traveled 5.4m km. The official announcement of the landing was flashed soon thereafter, stating that the cabin had landed smoothly, had been quickly recovered, and that the mission had been a complete success.

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But was it? There was no triumphant parading of the returned cabin in Beijing. No pictures were even released of it landing – difficult presumably, since it was dark. Officially, it was to be shipped to Beijing “shortly”. In no time, Western commentators were speculating that “something had gone wrong”. There were some reports that the cabin had been damaged at the final stage of landing because one of the parachute cords had broken free. Commentators further speculated a number of possibilities as to what might have gone wrong. Some time later, the Chinese stopped denying that there had been a hard landing, resulting from a broken parachute connection. It also emerged later that the spacecraft had briefly tumbled out of control during the separation of the orbital module.

Once again, the orbital module was detached for independent flight. This time, it carried out maneuvers, the first only a day later, with a propellant load sufficient to change velocity by up to 60 m/sec. These were used promptly on 17th January to raise the altitude of the module by 60 km and thus prolong its orbital lifetime. More surprises followed. The module maneuvered again on 20th February, raising its orbit from 375-391 km to 389-403 km, and again on 15th March, from 382-390 km to 394—405 km. After the March maneuver, 58 days after the start of the mission, the module’s orbit was allowed to decay naturally. By mid-August, it was down to 209 km, 88.9 min. The module eventually burned up on 24th August after 260 days (decay point was 33.1°S, 260.4°E, in the Pacific west of Chile).

The ability to maneuver clearly required an autonomous flight capacity, navigation, and control systems, as well as engines, fuel, and orientation systems.

Data were transmitted whenever the orbital module made an overpass of a ground station in China. The Russians had never used the Soyuz orbital module in this way and it had always been discarded as debris. The Chinese were far from reticent about the new assignment for the orbital module and hailed the experiment as a means of getting considerable scientific value added from an engineering test.

At this stage, China gave more details of the astronomy and astrophysics instruments. Shenzhou 2 carried China’s first big astronomical payload: a soft x – ray detector, hard x-ray detector, and gamma-ray detector which recorded both cosmic gamma-ray events and high-energy emissions from solar flares. The hard x – ray detector was the largest instrument, 14.3 kg in weight, and operating in the 20- 200-keV and 40-800-keV ranges. The gamma-ray detector was 9 kg, also self­triggering, operating in the 200-keV to 8-MeV range, and it could pick up bursts in any direction. The 8.2-kg soft x-ray detector had a range of 0.2-2 keV, with a small window, turned off every time it pointed to the Sun, for its self-protection. These instruments were originally to have been flown on the canceled Tianwen mission (Chapter 7). Later, they were rescheduled for an unspecified large spacecraft in 2000, but now found their way onto Shenzhou. Between them, they obtained complete light curves and energy spectra of high temporal resolution of several gamma-ray bursts, allowing astronomers to trace the evolution of high-energy radiation and its structure. The super-soft x-ray detector and gamma-ray detector worked until 25th June, marking the first Chinese set of observations of gamma – ray burst, six events being measured (duration and energy level), while 13 solar x – ray bursts were analyzed (spikes and subsequent decline). The instruments detected 100 solar flares, which were compared to observations made at the same time by the Japanese Yohkoh satellite. The space environment instruments were an atmospheric composition detector and an atmospheric density detector to determine the density of atomic oxygen, with a view to selecting the best orbiting altitude for the spaceship and the best type of protective material. The space environment experiment gave scientists a detailed mass spectral map of the atmospheric composition and density data, with a distribution map of the diurnal variation of the global atmospheric density. According to the Chinese, sensors examined the orbital environment to obtain key information on its composition, particle densities [4].