Chang'e 2

Description

Launched on 01 October 2010, the Chang'e 2 spacecraft was China's second lunar mission. Expanding on the goals of the Chang'e 1 mission, its will act as a technical test satellite for future Chinese lunar missions. Its principal objectives are to return high resolution images of the lunar surface to aid in selection of a future landing site for the Chang'e 3 lander and rover mission. A key technology for soft-landing on the Moon will also be tested.

Chang'e 2 was designed as a backup satellite for the Chang'e 1 spacecraft based on the DFH-3 Comsat bus. It has been modified for its current mission. The spacecraft carries a CCD stereo camera with spatial resolution of 10 m from the nominal 100 km altitude. A laser altimeter with a laser pulse frequency of 5 Hz and a radial accuracy of 5 m is mounted on the spacecraft.

Chang'e 2 launched from Xichang launch site on a Long March 3C booster at 10:59:57 UT on 01 October 2010. A 5-day trans-lunar cruise was followed by insertion into a 12 hour elliptical lunar polar orbit at 03:06 UT on 06 October followed by lowering to a 100 km nominal science orbit on 9 October. The primary science mission ended on 8 June 2011. Towards the end of the mission the orbit was lowered to 15 km x 100 km to test the tracking ability of a new X-band ground tracking system.

Chang'e 2 left lunar orbit and entered orbit at the L2 Sun-Earth Lagrange point on 25 August 2011. It left L2 orbit on 15 April 2012 and flew within about 3.2 km of asteroid 4179 Toutatis at 8:30:09 UT on 13 December 2012 and took close-up images at a relative velocity of 10.7 km/s.

The Chang'e program is named for a Chinese legend about a young fairy who flies to the Moon.