Herschel, Hubble, & Planck sounds like a law firm. Following up on the last post, the news certainly is good so far. Herschel and Planck successfully launched, and should be sending detailed info about our universe when it was just a cute little baby cosmos. And the Hubble repairs are doing well so far. No one’s been pinged by a piece of debris while they’re traveling at five miles per second around the earth.
Who put that dangerous debris up there? From what I’ve read, there are a couple big sources. One was the February 2009 collision of an Iridium communications satellite with a old Russian communications satellite. Another source is a satellite that China blew up as part of a missile test. They were all in the same general orbit. That, plus other orbital flotsam and jetsam persuaded NASA to declare a 1 in 185 chance of a catastrophic collision during this mission. I heard one of the astronauts say it was worth risking his life to repair the Hubble.
Why doesn’t the Hubble get torn up by the debris? It could. But the Hubble is mostly empty space and solar panels. It would have to get a direct hit on a camera or other important bit to really damage it. The shuttle, on the other hand, can’t afford many hits. There are too many crucial components, like the big pressurized area where the astronauts live.