From AP:

 

WASHINGTON - A large U.S. spy satellite has lost power and propulsion and could hit the Earth in late February or March, government officials said Saturday.    

 

Link:  http://news.yahoo.com/s/ap/20080126/ap_on_go_ot/dead_satellite_4 

 

 That could be an interesting event if it happens in an observable area at night.

With my luck it will happen behind me.

Heck , with my luck it'll pick my house to land on !

This satellite is known as "USA 193", catalog number 29651, international designation 06-057A.  Here's a news story about its launch:

http://www.spaceflightnow.com/delta/d322/status.html

It seems that not too many days or weeks after its launch, it was determined that it had failed.

Ed Cannon - Austin, Texas, USA

 This would be great to see and just as dangerous, since it is uncontrolled, it is going to be one for the TAB to guess where it will hit.

 I was reading this article earlier today -

http://technology.newscientist.com/article/dn13236-earthbound-satellite-nothing-to-worry-about.html

 

 Bovines Beware.

with my luck  it will happen on me!! LOL

From the New York Times:

WASHINGTON — The Pentagon plans to shoot down a disabled 5,000-pound spy satellite within the next two weeks, before it tumbles from orbit, because the rocket fuel it carries could be a danger to people, Pentagon officials said Thursday.

http://www.nytimes.com/2008/02/14/science/14cnd-satellite.html?_r=1&8au&emc=au&oref=login

 

 

Thanks for the update Curt!

 Is this any different from China shooting down one of their satellites last year? I can't remember the details, other than it happened. Is this just a good opportunity to show our might? Or is this really to protect us from falling fuel? Either way this is something big!

It is significantly different than what the Chinese did.  That one was in a 400+ mile high orbit, while USA 193 is now below 170 miles.  (We have a pass here Friday evening at an orbital height of 163 miles, and then the one Saturday evening is at 162 miles -- rapidly descending.  Too bad that it seems that both evenings will be cloudy here!)  Most of the debris from a break-up of USA 193 would re-enter before too long.  The Chinese used an orbit-capable missile on theirs.  The USA interceptors will be sub-orbital (Standard Missile 3), although apparently enhanced to go higher and farther than usual.

The debris danger, however small, is real.  The Aerospace Corp. has great information about re-entries.  Here's their page about recovered re-entry debris:

http://www.reentrynews.com/recovered.html

Here's their page about past re-entries (late 2000 to present):

http://www.reentrynews.com/past.html

Eight minutes or so after the Saturday evening pass of USA 193, we have a great pass of ISS and the Space Shuttle.  I sure wish it would be clear!

Ed Cannon - Austin, Texas, USA

I too am uneasy about this missile intercept.  True, this is a low orbit intercept but the resultant debris field is still a concern.  There is no guarantee that parts of this satellite won't remain in low earth orbit for years or that a significant amount of it will impact the surface anyway. I hope the final orbital burn-up is over the ocean so that the military does not have to do this.

L

The news says that it has a fuel tank that is full of hydrazine, (I guess that's some type of hypergolic fuel) and the fuel tank will survive reentry.   They say that they don't want anyone to possibly be contaminated with this highly toxic fuel.   Isn't that nice?   Why else would they want to shoot it down? I mean, what other reason would there be, to want to shoot down a spy satellite?   Well, it is a spy satellite. Doesn't it have solar panels to keep it's electrical system functioning?  No.  It's a spy satellite as big as a bus. What would they use to power a spy satellite for long term use?   Probably the same thing they used on the Voyager probes.    There's probably a small nuclear power plant inside that thing.   It would be shielded too, so it might even survive reentry if it came down.   If it didn't, it would leave a nice radiation trail across the sky. Would they want the American public, or the Russians, or China to know what they have on board that satellite?  I don't think so. Think about the optics that are aboard that thing.   There are any number of technological reasons for not wanting that thing to come down in some country, or even close enough to where someone could retrieve parts of it to study. What color do you think that satellite is?   If I didn't want anyone seeing it from the ground, I would want it to be as antireflective as possible.  I would have it be a dark dull black.   I would maybe coat it with the same material as those spy planes so that it has radar dampening capabilities too.   I would have the optics recessed inside, so that no light would glint off of the lenses.   Either way, I think the fuel explanation is probably the weakest explanation of all.   But hey, that's what the News says.   What do you think?

From some accounts this satellite has some very top secret monitoring equipment on board.   Also if it is successful, then destroying this satellite will send a reminder to the world, (China?) regarding US missile capabilities.

 What alarms me is that they are going to wait until the shuttle has landed before destroying the satellite.   They obviously think there is a possibility of debris remaining in low orbit for some time.  

I guess it will be shot down over the pacific.  Probably in daylight.

From what I have read the Chineese satellite that was destroyed left a large amount of debris in low orbit.  Soon traveling up there will be like dancing in a shooting gallery.  I think Aratus hit the nail on the head with his comments about destroying sensitive technology, and about sending a message.  I hope all goes well.  This plan is a little too cowboy for my taste.

The Chinese satellite was in an orbit more than 500 statute miles above the Earth's surface.  USA 193 is now at about 160 miles, and by Wednesday or Thursday may be down to 150 miles due to the drag of the atmosphere.  They are very different situations.  The International Space Station is at about 212-213 miles, I believe.

Ed Cannon - Austin, Texas, USA

 Does anyone know how this compares to our anti missile tests? Such as. How many miles up were the anti missile tests? Is it used with the same missile? Where will it be shot from? And finally. What is the risks of a miss?

I don't know much about the US anti-missile tests, but a big difference of course is that ICBMs are not in orbit.  The missile to be used with USA 193 is called "Standard Missile 3" (enhanced for this mission, I've read) and is launched from an Aegis cruiser.  The action will occur over the western Pacific Ocean sometime after the Space Shuttle lands on Wednesday.  My understanding of the SM-3 is that if it misses it will simply re-enter; it would be in that case simply a suborbital flight.

Ed Cannon - Austin, Texas, USA