October 24, 2007: XICHANG – The launch of China’s first lunar probe Chang’e-1, on a Long March CZ-3A booster, was successful, a Chinese official announced Wednesday evening at the Xichang Satellite Launch Center in southwest China’s Sichuan Province.
Li Shangfu, director of the Xichang launch center, made the announcement after the orbiter successfully entered the earth orbit and unfolded its solar panel, paving the way for its transfer to the lunar orbit.
Chang’e is expected to orbit the Moon for a year, testing technology for future missions and studying the lunar environment and surface regolith. Based on the DFH-3 Comsat bus, it has a mass of 2350 kg. Compare that with 3000 kg for Kaguya and 2180 kg for NASA’s Lunar Reconnaissance Orbiter.
The 130 kg payload includes a stereo camera system to map the lunar surface, an altimeter to measure the distance between the spacecraft and the surface, a gamma/X-ray spectrometer to study the overall composition and radioactive components of the Moon, a microwave radiometer to map the thickness of the lunar rego-lith, and a system of space environment monitors to collect data on the solar wind and near-lunar region.
Chang’e is named after a fairy goddess who in a Chinese legend flies to the Moon.
The Road to the Moon and Timeline
Chang’e’s path to the Moon will be similar to Kaguya’s. After perigee on each of three Earth orbits, a burn will extend its apogee higher to 51,000 km, 71,000 km and 120,000 km with orbital periods 16 h, 24 h and 48 h respectively.
A final translunar injection burn will place Chang’e on route to the Moon where it will go into a polar orbit around the Moon.
Burns at the first three perilunes (point of closest approach to the lunar surface) will lower the apolune, reducing the orbit period from 12 h to 3.5 h to 127 min at which the orbit will be circularized. After a checkout period, the science mission will begin.
1. Drawing “pictures” of the moon and obtaining three-dimensional images of the lunar surface. Dividing the basic landforms and structures of the lunar surface and initially making outline graphs of lunar geology and structures, so as to provide a reference and basis for later soft landings. The orbit of Chang’e 1 around the moon will provide complete coverage, including areas near the north and south poles not covered by previous missions.
2. Probing useful elements on the moon surface and analyzing the elements and materials, primarily making maps of the distribution of various elements on the moon’s surface. China hopes to expand the number of the useful elements to 14, compared with the five kinds previously probed by the United States, and will conduct an overall prospect evaluation on some useful resources on the moon’s surface.
3. Probing the features of lunar soil and evaluating its depth, as well as the amount of helium-3 resources.
4. Probing the space environment between 40,000 km and 400,000 km from the earth, recording data on the primitive solar wind and studying the impact of solar activity on the earth and the moon.
Moon Society Comment:
The worldwide Lunar Community congratulates China on its successful launch of its ambitious Chang’e-1 lunar orbiter, China’s first planetary mission. Following Japan’s successful launch of its own lunar orbiter, Kaguya, just 6 weeks ago on September 13th, this launch is the second salvo of an international effort, dubbed The Lunar Decade, to learn more about the Moon, with emphasis on preparation for manned Moon landings planned by several nations: India, China, Russia, and the US (NASA).
We are further encouraged that two additional major lunar orbiter missions are just around the corner. India’s Chandrayaan-1 is scheduled for launch in five and a half months on April 9, 2008. NASA’s Lunar Reconnaissance Orbiter will follow a year from now, in October 2008. The next two years should see a dramatic increase in public attention on the Moon as our picture of the Moon grows ever more detailed, answering many questions, but probably raising as many more, as always.
According to the Beijing Declaration, the nations involved in this effort are coordinating their efforts especially as to calibration of instruments and interchange of data, for the optimum improvement in our picture of the Moon, its origin, history, ongoing evolution, and resources significant for human pioneers.
The momentum of activities taking us back to the Moon, first for more information, then to establish permanent human presence, continues to increase. The international scope of this effort is gratifying as it provides considerable insurance that the effort will continue, even should never predictable political vagaries in the United States, limit, stretch out, or even cancel NASA’s current plans to establish a science outpost at one of the Moon’s poles.
Other nations are also planning human visits, and eventual outposts: China, India, and Russia. India, China, and Japan also are very much aware that the use of lunar resources could make possible solar power satellites that would make it possible for them to phase out dirtier power generation methods, chiefly those relying on coal.
In the United Space, while NASA has been reluctant to look beyond the scope of what it is budget to do, the National Security Space Office (NSSO) has found Space-Based Solar Power (SBSP) to be an especially promising way to reduce US dependence on foreign-oil and as a way to reduce global warming. The Moon Society applauded this report, joined a 13 member alliance to support it, and intends to aggressively push the plan. Whereas NASA is currently restricted to planning a science outpost, the NSSO plan, if implemented, would involve industrial civilian settlements on the Moon, more in keeping with the Society’s mission. The SBSP initiative would not fight for NASA funds, but be funded by the Department of Energy and/or the Department of Defense, removing the perennial worry over what Congress will or won’t do in support of NASA.