Bad Astronomy

Some space news

1) China’s first science satellite, Double Star TC-1, burned up in re-entry this week after a successful four-year mission studying Earth’s magnetosphere.

2) China’s first lunar probe – and the first of their claimed series of steps to putting a man on the Moon – will launch sometime between October 22 - 25.

3) NASA’s Far Ultraviolet Spectroscopic Explorer – FUSE – will be shut down after more than eight years of observing high-energy objects in space. I had a lot of friends who worked on FUSE (my old boss worked on the calibration of its very complicated spectrometer), so this makes me even sadder than usual. There aren’t a whole lot of UV missions right now; for example STIS shut down a few years back (though it may be repaired in the next Hubble servicing mission). GALEX is still going strong, which is nice. But the UV region of the spectrum is where a lot of dynamic things happen, and we still don’t know all that much about it. It sure would be nice to see us doing more in that area, not less.

FUSE, like most astronomical satellites, moves its view from target to target by using “reaction wheels”; a set of heavy, rapidly rotating disks. When they are slowed down or sped up, they transfer their angular momentum to the spacecraft, which responds by rotating around one axis. Over the years, the reaction wheels have been failing – they’re moving parts, after all – and the last one quit last spring. There is no choice but to shut down the observatory. A little weirdly, NASA has invited reporters to the FUSE control room when they switch it off on Thursday, a sort of viewing, I suppose. I’ll be curious to see what reporters write after seeing this.