Chang'e 1

▪ Chinese lunar probe

      the first lunar probe launched by the China National Space Administration. The satellite is named for a goddess who, according to Chinese legend, flew from Earth to the Moon. Chang'e 1's mission includes stereoscopic imaging of the lunar surface, assaying the chemistry of the surface, and testing technologies that could be used in expanding the Chinese national space program to the Moon. A Long March (launch vehicle) 3A rocket launched Chang'e 1 into an elliptical Earth orbit on Oct. 24, 2007. An upper stage injected it toward the Moon, and it entered lunar orbit on Nov. 5, 2007. Two days later, it settled into a 200-km (120-mile) near-polar orbit. It was expected to operate for at least a year.

      Chang'e 1 carries eight instruments. A stereo camera and a laser altimeter are developing a three-dimensional map of the surface, with the camera tilting forward, down, and aft to illuminate three charge-coupled device (CCD) arrays. The interferometer spectrometer imager uses a special lens system to project light onto an array of CCDs. X-ray and gamma-ray (gamma ray) spectrometers measure radiation emitted by naturally decaying heavy elements or produced in response to solar radiation. This spectral data will help quantify the amounts of minerals on the lunar surface. The microwave radiometer detects microwaves emitted by the Moon itself and thus measures the thickness of the debris layer, or regolith, that fills the huge basins called maria (mare). One aim of the regolith investigations is understanding how much helium-3 may be on the Moon. Helium-3 is a trace element in the solar wind, and the lunar surface has absorbed larger quantities of helium-3 than have been found on Earth. If mining on the moon were ever practical, helium-3 would be a valuable fuel for nuclear fusion power. Other instruments are monitoring the solar wind and space environment.

Dave Dooling, Jr.

 

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