Getting ready for challenges of space
Updated: 2011-12-30 08:51
By Hu Wenrui (China Daily)
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With the successful completion of the Tiangong-1, or Heavenly Palace mission, China showed the world that it had accomplished a major milestone in space technology by mastering the sophisticated interdisciplinary knowledge in building, delivering and sustaining a near-orbit complex space infrastructure.
This operation was composed of launching the Tiangong-1, an unmanned space laboratory module, followed by the launching of an unmanned spaceship, Shenzhou-8. Once both modules were in orbit, they were brought together and docked.
Behind each of these activities are tremendous demands on cross-functional support from different groups such as science, technology, and system management, and this requires a healthy economic and political environment.
China, after Russia and the United States, became the third member in the elite group of those with such a capability in manned space exploration. Step two of the Manned Space Engineering Program over the next few years will try to expand on existing infrastructure by building a pressurized module for astronauts to live and work in, building a fleet of vehicles to shuttle astronauts and cargo between the space module and ground base, and setting up facilities in the laboratory to conduct space experiments.
One of the goals of the project's third step will be to build a space station, with a manned microgravity laboratory by the end of the 2020s.
Space adventure reflects humanity's pioneering spirit, but it should not be forgotten that space exploration in its early years was overshadowed by hostile rivalry between the former Soviet Union and the US.
The human space era opened with the Soviet Union's launch of the first artificial satellite, Sputnik, in 1957. In 1961 Yuri Gagarin, from the Soviet Union, became the first human in space.
The US space program quickly caught up with its Apollo manned lunar landing program within months of Gagarin's feat and lasted until 1972. From the early 1970s the focus of space exploration was turned to building near-orbit space stations. The Soviet Union, and later Russia, developed the Salyut program, consisting of seven space stations, from 1971 to 1991. They also supported the Mir space station from 1986 to 2001. The US had its Skylab system from 1973 to 1979, together with an advanced space transport system, the space shuttle fleet, which operated between 1980 and 2011.
Throughout the years countless challenges in building space stations were resolved, gradually moving the technology toward perfection after more than 10 years of struggle. In 1982 Salyut 7 suffered an accidental power failure in its final phase and lost communication with ground control. In a rescue effort in 1985, Soyuz-T13 carried two astronauts and docked with Salyut 7 to restore its power supply and bring it back to life. This paved the way for another visit to Salyut 7 in 1986 by two other astronauts from the first team of the space station Mir.
After the successful Columbia space shuttle mission by the US, the Soviet Union decided to start a space shuttle program, codenamed Buran. Similarly, to keep up with programs like Mir, Western countries led by the US proposed to develop a space station called Freedom about the same time.
This hostile rivalry was a drain on the resources of both sides, and neither backed down until the Soviet Union broke up. In 1994, about three years after the collapse of the Soviet Union, the space station at the center of the program called Freedom was renamed the International Space Station (ISS), and space agencies from the US, Russia, Western Europe, Japan and Canada were invited to join the effort. China was left out. As of today, the ISS is the largest man-made structure in space, about four times larger than Mir.
Cutting-edge science and technological research are essential ingredients for any country that wants to assert itself in the modern world.
In China, six national committees were established in 1986, each devoted to one of the major research and development fields in advanced technology. One committee, on space, was proposed mainly as a vehicle to brainstorm the feasibility of a Chinese space station program, the primary focus being on technological and budget challenges.
The space committee came back with a final report in 1991, recommending a three-step strategy. The proposal called for a manned space ship program, followed by a manned space laboratory and then the building of a fully manned space station.
One rationale for the plan was the current rocket launching capacity of about 8 tons into lower Earth orbit, which would meet the payload requirement for the first two steps, giving time to develop a larger rocket as a parallel effort for step three. Also, to fully draw on the experience of unmanned recoverable satellites, the committee recommended the mature and more affordable approach of using a manned spaceship instead of a space shuttle.
On top of that, a relatively longer project timeline was proposed not only to ensure more time on design and operation but also to help spread the cost over lower yearly budgets. This approach is appropriate for developing countries like China, where it may not be realistic to propose 10-year space station programs like those of Russia and the US. The Chinese government accepted the proposal and turned over execution of the matter to the National Manned Space Engineering Program from 1992.
The first step of the program was successfully completed after numerous unmanned and manned flights of the Shenzhou spaceship over 10 years. The second step of the program is now well under way with several Tiangong space laboratories planned to be launched in coordination with a series of unmanned or manned Shenzhou spaceships. The latest mission of Tiangong-1 docking with Shenzhou-8 is a significant milestone in China's space station program.
Astronauts living and working in a space station operate in a microgravity environment, generally referred to as weightlessness.
Microgravity in a space station offers a great platform not only for improving understanding on how to better live and work in space, but also to explore science and application opportunities unknown to humanity for millennia, essentially stuck to the ground under the influence of gravity. Besides realizing a dream of space adventure, the space station will eventually help to elevate and expand certain knowledge in fundamental science and technology, promote high-tech development, inevitably introduce new commercial products, potentially improve health for human living on Earth and in space, and open up more opportunities for human exploration in outer space.
Considering the daunting task of running microgravity research at ground level, the space station brings with it a quantum leap in microgravity research fields that can help to make breakthroughs in areas such as fluid physics, combustion, materials science, biology and ecology, protein crystal growth, cell culture, biomedicine, human support system, and more. This space program has been and will continue to contribute to improved human welfare.
The author is an academician at the Chinese Academy of Sciences.