Space Junk 1: Science 0

Remember when that defunct Russian satellite crashed into the Iridium satellite a week or so ago? Lots of debris, some of which came down as weather? Well, not all the debris came down. Most was left in orbit, and apparently has already had some effect on other satellites, as people had feared. And worse for astronomers, Nature (subscription only) is now reporting that with the increased debris, the risk to the Space Shuttle and its crew may now have been pushed up to a level that precludes the upcoming servicing mission (SM4, currently scheduled for May). NASA is currently evaluating the situation, and we should all know more in a few weeks. But, if the servicing mission is cancelled, it's going to be a huge blow for astronomers. (It wouldn't be as tragic as losing another crew, however, so I completely support what NASA is doing in this case.) I'm speculating that if the servicing mission is cancelled, there might be an opportunity to try a robotic servicing mission, which would be good practice for learning how to eventually service satellites out at L2. But it seems unlikely that a robotic mission could bring the full complement of COS, WFC3, ACS, and STIC on-line, whereas the SM4 crew would have a good chance of getting them all in, along with other upgrades to the satellite's systems. (h/t to someone at dinner, who'd gotten a tip from Steinn's blog.)