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Chinese Moon Probe Flies By Asteroid Toutatis
hackingbear writes "Chinese moon probe Chang'e-2 made a flyby of the near-earth asteroid Toutatis on December 13 at 16:30:09 Beijing Time (08:30:09 GMT), the State Administration of Science, Technology and Industry for National Defense (SASTIND) announced today. The flyby was the first time an unmanned spacecraft launched from Earth has taken such a close viewing of the asteroid, named after a Celtic god, making China the fourth country after the U.S., the EU and Japan to be able to examine an asteroid by spacecraft. Chang'e-2 came as close as 3.2 km from Toutatis, which is about 7 million km away from the Earth, and took pictures of the asteroid at a relative velocity of 10.73 km per second, the SASTIND said in a statement. Chang'e-2, originally designated as the backup of Chang'e-1, left its lunar orbit for an extended mission to the Earth-Sun L2 Lagrangian point on June 9, 2011, after finishing its lunar objectives, and then again began its mission to Toutatis this year. 'The success of the extended missions also embodies that China now possesses spacecraft capable of interplanetary flight,' said Wu Weiren, chief designer of China's lunar probe program."
http://english.cri.cn/6909/2012/12/15/53s738568.htm
Le ciel va nous tomber sur la tête!
If you compare this image with the Goldstone image of Toutatis by Earth-based radar - see Figure 1 in Hudson et al - you can see that the Earth radar does OK, but actually going there is better. Toutatis's rotation period is 176 hours, so we won't get to see the other side in the flyby.
Note that there are a few craters, but not many (asteroid Itokawa has no craters in Hayabusa images), so as usual something is resurfacing the surface.
With Weak Stability Boundary theory trajectories you can basically get from a lunar transfer orbit (or either ES or EM L1/2) to anywhere else around without spending any fuel, if you are willing to wait long enough. This pdf presentation should give you the idea.
Now, in practice you can't do it with no fuel, but if you are willing to be patient, you can do amazing things with a piddling expenditure of delta-V.