Satellite could plummet to Earth

[glenc (Glen)]

A "large" US spy satellite has gone out of control and is expected to crash to Earth some time in late February or March, government sources say...In his estimate, the satellite weighs about 20,000 pounds (9,072kg) and is the size of a small bus.
http://news.bbc.co.uk/2/hi/science/nature/7211443.stm

[AJames]

Originally Posted by glenc

A "large" US spy satellite has gone out of control and is expected to crash to Earth some time in late February or March, government sources say...In his estimate, the satellite weighs about 20,000 pounds (9,072kg) and is the size of a small bus.
http://news.bbc.co.uk/2/hi/science/nature/7211443.stm

Gosh! Duck and Cover...

Odd Question: if you knew such a weight was coming down over the neighbourhood, would you have time to see the decent, and at at the last moment just get of the way? Let's hope it drops over the ocean somewhere!
I presume such satellites would break up in the fiery return before hitting the ground - which means it wouldn't be a problem, though if nuclear powered and it was fairly old you probably be worried about radioactive fallout.

[Ric]

By the sounds of it they have no idea yet where or where it is going to come down to earth but they are more worried who will see their secrets.

[madtuna (Steve)]

I hope it slams into outback NSW somewhere ..remember how much chunks of Skylab fetched when it hit WA in 79

[Glenhuon (Bill)]

Originally Posted by madtuna

I hope it slams into outback NSW somewhere ..remember how much chunks of Skylab fetched when it hit WA in 79

There's a bit of it on the roof of the Baladonia Motel, at least it was there about 14 months ago. One of the guys that worked for the WA Water Supply found a spherical tank from it, probably still got it, couldn't sell it. (probably wanted too much)

Bill

[Kal (Andrew)]

The Space shuttle weighed about 2000 tonnes when it unfortunately burned up on re-entry and crashed down to earth, making it 200 times larger than this satellite (for a matter of perspective)

[leon]

Well it can land in my back yard anytime, as long as i can see it coming and get out of the way. look, I probably shouldn't laugh, as long as it dose no serious damage or injure anyone

Leon

[Lee]

though if nuclear powered and it was fairly old you probably be worried about radioactive fallout.

Are any satellites nuclear powered??? I didn't think we had reactors that small to be in satelites - thought they were usually solar/battery. That said, I'm sure there are plenty of unsavoury chemicals etc up there.....

[AJames]

Originally Posted by Lee

Are any satellites nuclear powered??? I didn't think we had reactors that small to be in satelites - thought they were usually solar/battery. That said, I'm sure there are plenty of unsavoury chemicals etc up there.....

You are probably right. I might be thinking more of the old Russian satellites, which have fallen to earth in the past - one was in South America if I can recall.
I thought that some of these need significant power, and having to be as invisible as possible - kind of stealth mode - so solar panels would be a no no. Furthermore, most are thought to be dark non-reflective materials and probably invisible unless you really know what your looking for... (probably classified, so again I hope no one knocks on my door! If I don't post to this thread again, well you know...) Knowing when something is spying on you would seem pretty sloppy for your enemy.
As for chemicals, I'm unsure. Good point though...

Andrew

[[1ponders] (Paul)]

The Voyagers were nuclear powered

[h0ughy (David)]

Originally Posted by Lee

Are any satellites nuclear powered??? I didn't think we had reactors that small to be in satelites - thought they were usually solar/battery. That said, I'm sure there are plenty of unsavoury chemicals etc up there.....

dont they have a bit in them to keep themselves warm? ie as per voyager etc

[AJames]

Originally Posted by [1ponders]

The Voyagers were nuclear powered

Quite right. A couple pounds of radioactive plutonium used to power the cameras and keep the electronics warm. The plutonium is encased into stone-like material, and protected from an outer case - just on case it falls back to earth or the rocket explodes on take-off. However the older spacecraft were not made so well, especially the Russian ones due to cost cutting.
Plutonium is fairly toxic - not something that animal and human cells survive very well without chromosome damage and radiation sickness- and it doesn't take much of it either.
The reason why radioactive material is required to power the spacecraft away from the sun in the outer solar system, Nearer Earth all that is required is solar panels soaking up sunlight to generate free needed power for the satellite systems.

[Night Owl]

Originally Posted by AJames

Gosh! Duck and Cover...

Odd Question: if you knew such a weight was coming down over the neighbourhood, would you have time to see the decent, and at at the last moment just get of the way? Let's hope it drops over the ocean somewhere!
I presume such satellites would break up in the fiery return before hitting the ground - which means it wouldn't be a problem, though if nuclear powered and it was fairly old you probably be worried about radioactive fallout.

Old mate of mine, lived in England as a kid during WW2.
He told me that late in the war he was still evacuated from London to the quiet of rural life north of London, away from the V2 blitz. Anyway one afternoon he was outside of his house in the street and he looked up in the sky and saw a star gradually appear in the sky. He kept looking as the star got brighter, and brighter, and brighter, and then bigger and get really bright, and then saw it explode!

Old pat said he had an instinct to throw himself on the ground, and saw what eventually proved to be the remains of the engine assembly of a V2 missile demolish a garage just yards away.

What Pat had seen was the terminal dive of a V2's re-entry phase, and because V2's didn't have very good heatshields occasionally the 1 tonne warhead would "cook off" at some altitude due to dynamic heating, before it hit the ground. You can guess what would have happened if the warhead hadn't cooked off, as Pat said the star he was watching had no apparent movement. Pat died of prostate cancer in 1993. But he could have died in 1944!

"*(27) Oct. 04, (16.35 hours) - Battery 444, Rijsterbos, Middenleane, rocket fired, impacted at Spixworth no damage. This rocket fell apart before impact scattered over a large area. The entire engine, parts of the radio, etc., recovered and sent to research institute for Air Travel at Farnborough."

http://www.v2rocket.com/start/deployment/timeline.html

"Late that evening, an explosion rocked the Hellesdon area. An estimated 400 houses within a two-mile radius were damaged in some manner. The following day British authorities recovered the remains of a V-2, which broke up in the air before impact near Spixworth. The engine and various important parts were sent to Air Institute at Farnborough for analysis. —Robert Collis & Winston G. Ramsey, The Blitz Then and Now Volume 3, 1990"

http://www.v2rocket.com/start/deploy...erke-rijs.html

If you take the time read the information from these links you will be astounded at how many rockets were fired, and how many people were killed instantly with no warning. Werner Von Braun's dream exacted a heavy toll.

[citivolus (Ric)]

Don't forget Cosmos 954, which crashed into Northern Canada in 1978. It had a nuclear core, which was spread across an area of 40,000 square kilometres. Only 1% of the fuel was ever recovered.

[citivolus (Ric)]

A little update, the Cosmos series saw 33 nuclear reactor powered satellites put into orbit. Who knows how many others there have been...

The micro reactor was used to power the high power radar on these satellites.

[AJames]

Originally Posted by citivolus

A little update, the Cosmos series saw 33 nuclear reactor powered satellites put into orbit. Who knows how many others there have been...
The micro reactor was used to power the high power radar on these satellites.

Ah! Thanks for posting this... I didn't really know what they were using such power for the Russian satellites... Makes perfect sense now!

Andrew

[citivolus (Ric)]

Here's a list of acknowledged US RTGs (as mentioned in posts above) from 2001:

http://www.space.com/businesstechnol..._010625-6.html

The USA had an active development program investigating reactor use in the mid 80's, who knows what classified stuff may have been going on. I don't think I would want this particular satellite in my back yard, thanks.

[citivolus (Ric)]

Originally Posted by AJames

Ah! Thanks for posting this... I didn't really know what they were using such power for the Russian satellites for... Makes perfect sense now!

Andrew[/size][/font]

Interesting that they designed the core to be jettisoned prior to re-entry, so at least 14 of these reactors are still floating around up there in "disposal" orbits. Yikes.

Edit: Here is a more comprehensive list of RTGs and reactors:

http://www.space4peace.org/ianus/npsm3.htm

[citivolus (Ric)]

I finally managed to track down a designation on this satellite. It is NRO L-21, launched from Vandenberg AFB on December 14, 2006. It was an experimental satellite with classified equipment on board for testing purposes. From what I have read the chances of Hydrazine being left on board are high. While it is unlikely to have contained a reactor, I don't think anyone can rule out an RTG being on board. Well, those who could rule it out are not likely to say much.

Edit: Heavens Above has elements here: http://www.heavens-above.com/orbitdi...ET&satid=29651

[xelasnave]

No wonder we are becoming such a clever species not only can we solve problems but we can make them to...

alex