I answer six questions about it over at Popular Mechanics.
[Update a few minutes later]
Well, FEMA can relax — it won’t fall on us.
[Evening update, at least on the west coast]
Yes, I know that Skylab came in in 1979. I hope it will be fixed tomorrow.
I thought space junk stayed in orbit forever – like in WALL-E.
Slight correction:
Even a couple hours before the event, the Joint Space Operations Center (JSpOC, formerly known as NORAD) will be able to predict the location only to within a few minutes and a few thousand miles—about a quarter of the way around the planet.
NORAD still exists here in Colorado Springs. The Space Surveillance Center was moved from Cheyenne Mountain to the JSpOC at Vandenberg AFB, CA a few years ago (a mistake, IMO).
Why didn’t they deorbit it earlier when they still had enough propellant to target it more accurately?
On point 3, I still think it remarkable that Columbia debris managed not to hit anybody, at least not significantly. Happy about that since my wife and daughter were in the area of the debris field.
@MPM, read the article, there wasn’t enough propellant to move it to a stable orbit or to force a predictable reentry.
I did read it, I wondered why they didn’t deorbit it earlier when they still had enough propellant. Maybe they would have had to deorbit it years ago, who knows?
http://www.youtube.com/watch?v=NAr2HkQr1YM
Agree with MPM. It seems they burned through the propellant too fast, and then instead of ending the program early to allow for proper decommissioning, they settled for what we have now. I’m sure they considered the risk, but I bet the advocate for early decommissioning was probably paid in some way by NASA.
It’s not quite true that no one has ever been hit by man-made space debris. A woman in Texas had a fragment of what appears to be a Delta II upper stage brush her shoulder. She wasn’t injured.
My colleagues who work on this stuff have a slightly more accurate way to say that: “She wasn’t injured because she didn’t have a good lawyer.”
It looks like today’s update shows the probability of a US footprint has gone up again. If I’m reading the tick marks correctly, if UARS enters 25 minutes earlier than nominal (with the current uncertainty being +/- 5 hours), debris would hit somewhere in the Dakotas… your mileage may vary….
http://reentrynews.aero.org/1991063b.html
But what’s the probability that the prediction will change?
“But what’s the probability that the prediction will change?”
They’re saying it’s 50/50 that it will fall on the United States…though there’s only a 10% chance of that.
Did it fall or what? I haven’t heard. I guess that means nobody got knocked in the head?