US spy satellite falling to earth

matt weber wrote:
On Sun, 27 Jan 2008 21:38:53 +0900, Stealth Pilot
wrote:

On Sun, 27 Jan 2008 11:53:50 +1100, Sylvia Else
wrote:

BradGuth wrote:
On Jan 26, 4:24 pm, Sylvia Else wrote:
http://www.news.com.au/dailytelegrap...116226-5001028,...

""We are looking at potential options to mitigate any possible damage
this satellite may cause," he said."

I wonder what options they might be.

Sylvia.
I think China could help, or possibly our ABLs.
- Brad Guth
It's not clear to me that blowing it to pieces is a good idea. I think
all the debris would soon re-enter, but I'm not sure.

Of course, there's a clear risk that you'll end up with a large piece
intact which then lands where it can do a lot of damage, and people will
say it should have been left alone.

On balance, I suspect attempting to shoot it down is a bad idea.

What's clearly required is something that can snare it and apply a
controlled de-orbit burn to bring it down somewhere safe, but developing
such technology is not going to be on anyone's priority list until after
the first city takes a hit.

Anyone know what kind of orbit a spy satellite would be in? Would they
always be polar, or might Sydney be safe?

Sylvia.
if you can catch it why not refuel it and push it back into a stable
orbit?
You are talking about an object that probably weighs 10-15 tonnes,
and if you got a good look at it, probably bears striking resembelence
to the Hubble Space Telescope. From what's been said publicly, it is
almost certainly a KH10 or KH11.

Trouble is, what's been said publicly is probably a lot of hooey.

The spacecraft in question is almost certainly USA-193, which was
launched on a Delta II in 2006. That would preclude it being a 10-15
tonne KH-10 or 11 class bird, since the Delta II can't lift that much.
It is more likely that it is in the 10 klb class and that somehow got
mangled into 10 tonnes.

The bind with catching is that depending upon exactly what has gone
wrong, it may not be catchable. For example if the communication link
has gone out, it may still be catchable, because the stabilization
system is probably still operation. If it truly is a complete power
failure, what you have is 15 tonnes turning at an unknown rate
probably about all 3 axes.

It's a moot point since there is no chance of a "catch" mission being
fielded before the bird re-enters.

The problem with simply blowing it up, is the fact that you
converted 1 piece of junk in several thousand with a total mass of
perhaps 15 tonnes. Major hazard to navigation! If you are going to
blow up, do so from above and in front so that the bits de-orbit
promptly.

Even then many bits will remain in orbit. The explosion would be
omnidirectional and the bits ejected posigrade will gain enough velocity
to offset the retrograde velocity of the impactor. The US does not have
an operational ASAT system anyway. There will be no attempt to blow up
this bird.