Chang'e 1

Chang’e 1 (simplified Chinese: 嫦娥一号; traditional Chinese: 嫦娥一號; pinyin: Cháng'é Yī Hào), an un-manned lunar orbiting spacecraft, is part of the first phase of the Chinese Lunar Exploration Program. This first phase is called "Orbiting (Chang’e-1)".

The spacecraft is named after the Chinese goddess of the Moon, Chang'e, pronounced roughly as chang-uh.

According to the schedule, detailed program design of the first milestone was completed by September 2004. Research and development of a prototype probe and relevant testing of the probe were finished before the end of 2005. Design, manufacture, general assembly, test and ground experiments of the lunar orbiter were finished before December 2006. Chang'e 1 was launched at 10:05 GMT on October 24 2007 from the Xichang Satellite Launch Center. It left lunar transfer orbit on October 31 and entered lunar orbit on November 5 [1].

The first picture of the Moon was relayed on November 26 2007. The mission is scheduled to continue for a year.

Objectives

The "Orbiting (Chang’e-1)" phase of the program has four major goals:

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 (potassium (K), thorium (Th), uranium (U), oxygen (O), silicon (Si), magnesium (Mg), aluminum (Al), calcium (Ca), tellurium (Te), titanium (Ti), sodium (Na), manganese (Mn), chromium (Cr), and lanthanum (La)), compared with the 10 elements (K, U, Th, Fe (iron), Ti, O, Si, Al, Mg, and Ca) previously probed by the NASA's Lunar Prospector, 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 (³He) 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.

The first three of the four objectives are aimed at the Moon itself, while the last one is focused on the process of sending the Chang'e probe to the Moon, which means exploring the physical environment between the Earth and the Moon.

In addition, the lunar probe engineering system, composed of five major systems - the satellite system, the launch vehicle system, the launch site system, the monitoring and control system and the ground application system - will accomplish the following five goals:

• Researching, developing and launching China's first lunar probe satellite
• Initially mastering the basic probe technology of satellites in orbit
• Conducting first lunar scientific exploration
• Initially forming a lunar probe space engineering system
• Accumulating experience for the later phases of the lunar probe project

Design

The Chang'e 1 satellite carries 24 pieces of lunar probe equipment, including a CCD stereo camera, microprobe instruments and a high-energy sun particle detector. The satellite weighs 2,350 kg, with 130 kg of payload, and is designed to orbit the Moon for one year.

Originally scheduled for April 2007, the launch was postponed to allow a better time for sending the satellite to orbit. Chang'e 1 was launched at 10:05 GMT on 24 October 2007 with a Long March 3A rocket from Xichang Satellite Launch Center in Sichuan Province.

After liftoff, Chang'e 1 made three orbits around the Earth, a burn at perigee extending the orbit's apogee further each time, until a final translunar injection burn placed it on course for the Moon on 31 October 2007. Another burn placed it in a polar orbit around the Moon, with burns at the perilune of the first three orbits decreasing the apolune until it entered a final circular orbit. Entrance into Lunar orbit was achieved on the 5 November 2007. At this occasion, the probe transmitted 30 classical Chinese songs and music pieces, including “My Motherland”, “The Song of the Yangtze River”, and “High Mountains and Flowing Water”.

As well as Chinese tracking stations, the Maspalomas Station ESA tracking station is being used to transmit signals to and from the probe.

The first pictures of the Moon were relayed on 26th November 2007.

Instruments

• Stereo camera with an optical resolution of 120 m and spectrometer imager from 0.48 µm to 0.96 µm wavelength.
• Laser altimeter with 1064 nm, 150 µJ laser and a resolution of 1 m.
• Imaging spectrometer
• Gamma and X-ray spectrometer for an energy range from 0.5 to 50 keV for x-rays and 300 keV to 9 MeV for gamma rays.
• Microwave radiometer detecting 3, 7.8, 19.35 and 37 GHz with a maximal penetration depth of 30, 20, 10, 1 m and a thermal resolution of 0.5 K.
• High energy particle detector and two solar wind detectors capable of the detection of electrons and heavy ions up to 730 MeV.

Images Obtained

• Wan-Hoo crater
  Wan-Hoo crater
• Moon surface and its 3D view
  Moon surface and its 3D view

See also

• Exploration of the Moon
• List of future lunar missions

External links

• CLEP Official site
• Chang'e 1 Mission Profile by NASA's Solar System Exploration
• Encyclopedia Astronautica
• The Scientific Objectives of Chinese Lunar Exploration Project by Ouyang Ziyuan
• YouTube video of launch
• Chinese State Media Coverage (CCTV) in English
• Europe, China Cooperate To Radio Lunar Probe