Source: clep.org.cn
10-20-2007 11:06
Chief Commander for Chang’e Program, Luan Enjie
The Chang’e-1 orbiter to be launched in Phase 1 of China’s lunar program has four science objectives:
• To “draw” pictures of the moon, or to obtain 3-dimensional imagery of the lunar surface
• To detect the contents and distribution of a number of chemical elements on the lunar surface
• To probe preliminarily the depth of lunar soil, or regolith
• To explore the cislunar space environment
To finish these four tasks, Chang’e-1 carries six kinds of payloads, including a total of 25 devices arranged in eight instruments.
• Optical Imaging System
- CCD Stereo Camera
- Interferometer Spectrometer Imager
• Laser Altimeter
• Gamma/X-Ray Spectrometers
• Microwave Detector
• Space Environment Monitor System
- High-Energy Solar Particle Detector
- Low-Energy Ion Detector
• Payload Data Management System
Among these instruments, the CCD optical system will use a series of three 2-dimensional original images of a target area, taken before, during and after flyover of the spacecraft, to reconfigure a 3-dimensional image of the lunar surface. This demands a higher accuracy in attitude control and orbital determination.
CCD Stereo Camera
The Interferometer Spectrometer Imager is a camera that obtains images based on the fact that different objects have different spectrum properties. It will be used to perform multi-spectral remote sensing of the lunar surface. By filling spectral information into the digital lunar terrains obtained through stereo imaging, scientists will be able conduct researches on the properties of regional resources and materials.
Interferometer Spectrometer Imager
The Laser Altimeter will be used to provide complementary data to the elevation data of lunar surface and to refine the lunar surface digital model.
Laser Altimeter
The Gamma/X-ray spectrometers can obtain the distribution of different elements according to the differences of energy spectra of gamma and X rays emitted by various elements due to cosmic ray excitation, such as the gamma-ray spectra for elements of Th, U and K, and X-ray spectra for elements of Na, S and Ni. The data concerning elements of Fe, Ti, Al and Mg can be obtained through both gamma- and X-ray spectra.
Microwave Detector: Microwave/millimeter-wave radiometer is usually used on satellite. According to the different depths penetrating into lunar soil of microwaves in different bands, lunar soil depth data can be obtained by measuring the microwave radiation brightness of the regolith in given bands. This is a kind of passive measurement. The microwave detector on Chang’e-1 will operate in four different frequency bands.
Space Environment Monitor System: It is mainly to measure the contents of heavy ions, energy spectra of protons and contents and spatial distribution of low-energy ions in solar wind.
Editor:Liu Fang
