Wednesday, February 20, 2008

USA 193: it won't come down immediately

There is a big misconception in the media reports about the attempted kinetic attack on USA 193 that may happen tomorrow night: it won't come down immediately after being shot. Instead, the fragments of the satellite will continue to orbit. Atmospheric drag will greatly increase on each fragment, but it's certainly not coming down immediately over Canada as everyone says. At least some of the commenters on this Wired blog mention that.

But, it appears its perigee is at the northernmost part of its orbit (if I'm reading the orbital elements right), which is right after the interception. I bet they are thinking an orbit or two later it will come down over the northern Pacific.

1 comment:

Milligan said...

I loaded up the last reported elements and took a look outside over the following couple of orbits when it would have been passing over the Midwest. Didn't see anything unusual, and even with a full moon I think any large fragments reentering would have been apparent. So my guess is that any large chunks are still up there.

Have you seen the video of the collision yet? It's pretty obvious that there's a fair cloud of debris left.