To the Moon and Mars
October 2007 saw China launch its first Moon probe, the Chang e, and, by the following year, three Asian powers had spacecraft circling the Moon in a mini-space race between China, India, and Japan. It was followed by a second orbiter, with an extensive program of lunar research in the pipeline, with missions to Mars to follow.
PROJECT 211
Like most of China’s space projects, the roots of the Chinese Moon program went back some way. The first paper studies dated to 1962, when the University of Nanjing presented a text about a simple probe able to hit the Moon, as Russia had done in 1959. President Carter presented China with 500 g of lunar rock in 1978 and this was carefully studied by Chinese scientists.
UnUke the manned program, there were no rumors of Chinese Moon probes in the 1970s or 1980s, but China cannot but have noticed how, in 1990, Japan broke the superpower monopoly on missions to the Moon when it sent the small probes Hiten and Hagoromo there. Consideration was given to launching a Moon probe in 1994 rather than a manned space program, but it was decided to give priority to the more ambitious manned program and delay the Moon probe for the time being [1]. The idea of a Moon probe would not go away, for, at a 1995 Chinese Academy of Sciences conference, the director of space research, Professor Jiang Jingshan, told journalists that a pre-study of a lunar satellite was under way following a proposal by one of its senior members, Min Gurong. In 1997, three designers obtained funding under project 863 to research a possible lunar program. Yang Yiachi, Wang Dayan, and Chen Fangyun pubhshed their results under the title of Recommendations for the Development of China’s Lunar Exploration Program. The following year, an expert group was appointed, issuing a report entitled Overall Design and Key Technology Elements of a Lunar Exploratory Robot. This set three objectives for a Chinese Moon probe: improved knowledge of the formation of the lunar surface, its gorges, and craters; monitoring, from the lunar surface, the solar wind, radiation, and meteors; and analysis of lunar rocks with an on-board laboratory, to detect the presence of Helium 3.
B. Harvey, China in Space: The Great Leap Forward, Springer Praxis Books,
DOI 10.1007/978-l-4614-5043-6_9, © Springer Science+Business Media New York 2013
Symposia on lunar probes were held at Tsinghua University early in the new century. The Dean of the Department of Computer Science and Technology at Tsinghua University, Sun Zengqi, told the International Conference on Engineering and Technological Sciences 2000 that his department had explored a range of robotic technologies that could be used for lunar exploration – in collecting samples, exploring the lunar surface, deploying instruments, sending back television, and, ultimately, paving the way for manned landings. At the same time, Tsinghua University completed a study of the robotics involved in a lunar sample return mission modeled on that carried out by Russia’s Luna 16, 20, and 24 in 1970-76. An imported Japanese robot was rebuilt so that it could be manipulated, from the Earth, to grasp rocks to be lifted up and placed in a recovery capsule for return to the Earth. The following year, the university built a model miniature six-wheel solar – powered lunar rover, not unlike the Sojourner rover landed by the Americans on Mars. About a dozen institutes became involved in rover design in the early 2000s, such as the Shenyang Institute of Automation.
The lunar program was discussed at the China aerospace forum over 8th – 9th October 2001. The conference, entitled Policy and Perspectives on China Aerospace Development, was told by Xu Dazhe of the Chinese National Space Administration (CNSA) that China was capable of a lunar mission. The following month, on the anniversary of the government white paper on space exploration (see Chapter 10), Liang Sili of the China Academy of Sciences and Sun Laiyan, vicedirector of the CNSA, gave 2005 as the target date for the first Chinese unmanned mission to the Moon. In January 2002, the China Space Journal outlined the three prospective lunar missions: an orbiter, soft-lander, and sample return mission. Writers argued that China could start its lunar program with relatively sophisticated probes: there was no need to repeat the type of basic missions flown by the United States and Soviet Union in the early years of the Moon race. In May 2002, chemistry expert and director of the Beijing national observatory Ouyang Ziyuan was appointed chief scientist for China’s Moon exploration project. The cooperation program with Russia was extended to add missions to the Moon, Mars, and further afield. By the following year, no fewer than 67 papers had been put into the public domain about how China might carry out a lunar mission.
Approval for a Chinese lunar mission was finally given at a meeting of the government on 28th February 2003 and given the title project 211 (apparently, the first space project approved in the twenty-first century). It was given a popular title, the Chang e program (pronounced in EngUsh “chung-ur”), called after a beautiful fairy who took a magic potion, flew to the Moon, and became a celestial goddess. Appointed to guide the project were Sun Jiadong, chief designer, veteran of many programs, most recently Beidou, and aged almost 80; Ye Peijian, designer; and Ouyang Ziyan, chief scientist. ¥1.4bn (€140m) were allocated, the cost to be kept down by the use of existing systems. Four broad aims were set down, to:
• image the Moon in three dimensions to determine its structure, topography, craters, history, and structural evolution;
• determine the contents and distribution of its chemical elements;
Chang e Moon probe, following a well-established design. Courtesy: Paolo Ulivi. |
• measure the thickness of its regolith; and
• explore the particle and radiation environment around the Moon.
To organize the mission, a Lunar Exploration and Engineering Centre was established in 2005, directed by Hu Hao. To guide its scientific purpose, China set up a Lunar and Planetary Science Research Centre in the Institute of Geochemistry of the Chinese Academy of Sciences (this echoed the Vernadsky Institute in the Soviet Academy of Sciences which had a comparable function). This was Ouyang Ziyuan’s responsibility: he had graduated from university in 1956 and was the principal campaigner for the Chinese lunar program (indeed, his wish list of manned lunar missions was often mistaken in the Western press as an approved government plan). Ouyang Ziyuan had already published, in 1998, an article with his colleagues Wenzhu Lin and Shijie Wang called “Cosmochemistry” {Episodes, 18(1-2)) followed, in 2005, by Introduction to Lunar Science (2005, China Astronautic Press).
A Dong Fang Hong 3 comsat was adapted for the mission, to save the expensive construction of a completely new spacecraft. It weighed 2,350 kg but, because of the complex trajectory to be followed, half was fuel. The weight of the payload was small, drawing 161 W of power, and it was announced in spring 2007; the details are shown in Table 9.1. The data transmission rate was to be 3 MB/sec.
Following the mission required substantial investment in a ground tracking system. In spring 2006, construction began of a new tracking dish, 40 m across, 2,000 m atop Phoenix Mountain, Kunming, Yunan, which would work with other dishes near Shanghai and Xinjiang. Later, a 50-m dish near Beijing was added to the system. For practice, the European Space Agency (ESA) allowed China to use its tracking system to follow the European SMART 1 lunar mission. In 2011, China signed an agreement with Argentina for the use of its dish at the radio astronomy observatory at Felix Aguilar in San Juan [2].
Table 9.1. Chang e instruments.
Stereo camera to take three-dimensional images: resolution 120 m, swath 60 km, weight 31 kg
Ultraviolet imager
Interfering imaging spectrometer in 32 bands: resolution 200 m, swath 25.6 km
Laser altimeter: resolution 1 m, wavelength 1,064 nm, weight 11 kg
Gamma ray spectrometer: 300 keV to 9 MeV, to detect up to 14 chemical elements, weight 35 kg
Remote microwave radiometer to determine depth regolith, detect Helium 3: depth 30 m, resolution 0.5°C in 9.4 GHz, 19.4 GHz, and 37 GHz, aperture 50 cm (also called microwave sounder)
High-energy particle detector for protons 4-400 MeV, to measure heavy ions, helium, lithium, calcium, weight 2.4 kg
Low-energy solar wind ion detector up to 730 MeV, weight 7 kg
X-ray spectrometer: range 0.5-60 KeV