SHI JIAN 8

This appeared to end the series. The long-promised seeds satellite, flown as Shi Jian 8 and launched from Jiuquan on 9th September 2006, is, for convenience, reviewed here (the rest of the Shi Jian series is reported in Chapter 7). Although it has a different designator, we know that it was an FSW cabin and it was many times referred to by the Chinese as the “23rd recoverable mission” and as an FSW 3 series mission. The orbit was similar to other Jian Bing 4s, with a perigee of 178 km and apogee of 449 km. A day into the mission, it was reported that the seeds and fungi
were already sprouting: high-definition cameras sent back pictures of their growth every two hours to Xian mission control for forwarding on to the Shanghai Institute for Biological Science. The recoverable satellite came down after 15 days on the morning of 24th September, while the orbital module stayed aloft for another three days. It is also possible that it was the last film-based photo-reconnaissance mission. Shi Jian 8 was brought for examination to the Chinese Academy of Agricultural Science, where its seeds, vegetables, plans, fruits, grains, and cotton were handed over to the Institute for Plant Physiology and the Shanghai Institute for Biological Sciences.

An important breakthrough in Shi Jian 8 was live and recorded video broadcasting of experiments under way. Shi Jian 8 had a volume of 0.9 m3, 0.45 m3 in the recovered cabin, and an overall payload of 600 kg including a down payload of 250 kg. There were 215 kg of vegetables, fruit, grains, seeds, and cotton on board of 2,000 types, 152 species, 202 accessions, 80 groups, and 9 plant types. Shi Jian 8 carried experiments on the mutation of seeds, cell cultivation, mass transfer, granular media, surface deformation, boiling water, fire resistance, higher plants, smoldering, and a spring accelerometer. The satellite had a 256-GB memory, transmitting daily downlink on S-band at 8 MB a day in 25-min passes. Most FSW experiments were designed to be operated automatically, using a pre-programmed timer, but some were commanded on by telemetry. Whereas the seeds experiments were located in the recoverable module, the materials processing experiments appear to have been located in the orbital module. The orbital module experiments are listed in Table 4.1.

Looking at the experiments in more detail, Shi Jian 8 carried a Mach-Zehnder interferometer, a system of light beams to measure the behavior of water droplets in a protein solution in zero gravity, named after Ludwig Mach (son of Ernst, who invented the Mach number) and Ludwig Zehnder. An exotic experiment undertaken with French scientists studied the behavior of granular gas balls [13]. Shi Jian 8 continued the heating and boiling experiments first tried on FSW 22, this time using a plate heater. Water droplets were immersed in protein solutions. An experiment in granular matter was carried out to test, using video, the Maxwell demon effect (an experiment developed by James Clerk Maxwell to test the laws of thermodynamics).

An important experiment carried out tests on one of the great dangers of spaceflight: fire. In 1967, the Apollo 1 astronauts had died when a smoldering wire caused a fire, which, in an oxygen-rich atmosphere, rapidly consumed the cabin.

Table 4.1. Shi Jian 8 orbital module experiments.

Smoldering and combustion in microgravity Fire transmission by wires in microgravity Heat transfer in microgravity Granular media in microgravity Mass transfer in microgravity Development of mice embryos in microgravity Effects of microgravity on Chinese cabbage

Smoldering fires were subsequently detected on five shuttle missions (STS-6, 28, 35, 40, and 50). Here, an experiment found that the heat-loss factors that normally dissipate smoldering on the Earth were much reduced in weightlessness, making such pre-fires potentially far more dangerous. Electric wiring was much more likely to overheat and catch fire than on the ground. It was found that, in a 21% oxygen environment, smoldering flame on polyurethane foam did not progress but, at 35%, oxygen turned to flame and spread fast [14].

Four Kunming white mice early-stage cell embryos were carried on the non­recoverable module: they were photographed every three hours for 72 hr and it was found that the embryos failed to develop normally (none got beyond eight cells), unlike an identical ground control set. Scientists came to the conclusion that microgravity had a lethal effect on embryos at an early stage. Also in the orbital module was a garden of eight Chinese cabbages, the aim being to follow the growth cycle from germination through to pollination. The garden had lamps to illuminate the plants and cameras took pictures every 2 hr. Although leaf shapes were unaffected by weightlessness, there were fewer leaves and they grew shorter, more slowly, and wilted before the petals had even fully extended [15].

At the time of this mission, it was announced that it would be followed by Shi Jian 10 for a 28-day mission in microgravity and life sciences – a mission originally scheduled for 2010 but which slipped. The aim is to carry 20 experiments in microgravity fluid physics, microgravity combustion, space materials science, fundamental space physics, space biotechnology, and to study the biological effect of gravity and radiation. The materials processing experiments would focus on crystal growth from melt, under-cooling, crystal growth solutions, nucleation, and the solidification of alloys. While awaiting the next mission, China’s following cargo flew on a Russian satellite, Foton М3, in September 2007, using its Polizon-M furnace to test new materials for Diluted Magnetic Semiconductors (DMS). The experiment involved creating a rotating magnetic field around a heated, growing crystal [16].