Satellite could plummet to Earth

[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

[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. :mad2:

[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]

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

[Glenhuon]

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]

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. :lol: look, I probably shouldn't laugh, as long as it dose no serious damage or injure anyone ;)

Leon :thumbsup:

[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.....

[AJames]

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... :thumbsup:

Andrew

[[1ponders]]

The Voyagers were nuclear powered ;)

[h0ughy]

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

[AJames]

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]

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/deployment/serooskerke-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]

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]

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]

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

Andrew[/SIZE][/FONT]

[citivolus]

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

http://www.space.com/businesstechnology/nuclear_space_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]

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]

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/orbitdisplay.asp?lat=0&lng=0&alt=0&loc=Unspecified&TZ=CET&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

[AJames]

This same story has popped up on Universe Today.

http://www.universetoday.com/2008/01/27/us-spy-satellite-could-impact-with-earth-in-february/#more-12591

Here they state;


Fun, they don't mention nuclear material at all.
Could they be actually be frightened of US security here?

[MrB]

Cool, was wondering how the reactors worked in satellites. Was thinking it could be done with the Seebeck effect*. Then the posts about RTG's had me wondering what an RTG was, the Wikipedia entry answered it nicely for me.
One thing thats not explained in the wiki tho, is how the cold side of the Seebeck devices are cooled. I s'pose it's the coolant system that keeps the rest of the satellite warm? Anyone know?
Just figured if there was any excess heat that a convection-heatsink Isn't gonna be very helpfull in space! Maybe they have some sort of Emissivity-heatsink?

* If you have a Peltier cooled camera, next time you pack it in for the night and power it down, have a small low voltage light globe handy and run it off the cold Peltier. Your Peltier device just became a Seebeck device. :)

[space oddity]

I heard from someone, unconfirmed, that NASA insists that all pieces of skylab are their's and private ownership of pieces is forbidden. Explains why I have not seen skylab pieces on Ebay. If NASA were able to lay claim on all pieces of skylab, then such pieces are effectively worthless!

[madtuna]

Actually there is a museum in Esperence W.A. with a stack of Skylab chunks and numerous pieces in the hands of private collectors.

Esperance council actually issued N.A.S.A. with a ticket for littering which they still haven't paid...I say cancel thier drivers licence!:)

[rowena]

Imagine how much interest that ticket would have on it now!

Be scary to see what the fine would be now some 25+ years on...

[citivolus]

Some good info here:

http://www.globalsecurity.org/space/systems/e-305.htm

It speculates a significantly lower mass for the satellite than given elsewhere.

[AJames]

Thanks for this. Clearly the satellite must not be classified as stated,
Though others Ie. http://space.skyrocket.de/index_frame.htm?http://skyrocket.de/space/doc_sdat/nrol-21.htm

"NROL 21 is the cover-name for one-off classified satellite. Although nothing is known about the mission, the orbit hints for an experimental radar reconnaisance satellite."

The plot thickens, the satellite in the site you give is a drawing of a deployed solar array, but the statement in the site you give says;

"Soon after launch John Locker in the UK reported that the NROL-21 satellite failed within hours of its launch and the solar arrays never deployed."

Yet at;
http://www.globalsecurity.org/space/library/report/2008/080128-fia-vick.htm

"The rectangular bus box does appear to be covered with solar arrays and the spacecraft does appear to be darker than would be expected except for the down link dish rack and un-deployed hardware. At least they did not deploy properly thus the reports of the general power failure. That is at least my present impression based on the interpretation of the low resolution spacecraft imagery. To a degree I am speculating here based on low resolution ground based imagery and what we can gather from its appearance. I would have to say once I saw this imagery the common FIA bus idea vanished from my present thinking."

This is the most cryptic double speak I've read for a while...

Frankly with all this spin here - anything could be the truth...

Just hope it doesn't fall in my backyard !

[glenc]

http://news.smh.com.au/us-to-shoot-down-satellite-officials/20080215-1sfb.html
"President George W. Bush has directed a US warship to shoot down an out-of-commission spy satellite before it crashes to Earth, senior US officials said Thursday.
"The president directed the Department of Defense to carry out the intercept" after concluding that it would help prevent loss of life from the uncontrolled descent, said Deputy National Security Adviser James Jeffrey.
Jeffrey and other senior officials said the risk posed by an estimated 1,000 pounds of hydrazine, a toxic propellant, aboard the schoolbus-sized satellite was a key factor in the decision.
They denied that it was driven by the desire to protect the highly classified satellite's secrets, or that the shoot-down was intended to demonstrate a US anti-satellite defense capability..."

I am not convinced.

[Kal]

Isn't that the solution that George.W.Bush uses for everything - blow it up :whistle::lol:

[koputai]

That's funny, what with this coming two days after they had a go at the Chinese for doing the same thing!

Cheers,
Jason.

[citivolus]

I'm curious how visible the debris cloud from this would be, given that it would be making a pass over Australia around 5-7 hours after a North Pacific descending node intercept. Given that they want to hit it quite high up, pieces would be re-entering for quite a few orbits afterwards, possibly days/weeks. Expect a light show if it is night here.

I'm also amused that they say the most likely piece to survive an intercept would be the fuel tank, despite the fact that it is the piece they claim to be aiming to destroy. Look out below!

[glenc]

Russia has accused the US of using a plan to shoot down a broken spy satellite as a cover for testing an anti-satellite weapon.
The US said last week that it would use a missile to destroy the satellite, to stop it from crash landing. Officials say the satellite contains hazardous fuel which could kill humans. But Russia's defence ministry said the US planned to test its "anti-missile defence system's capability to destroy other countries' satellites"...
http://news.bbc.co.uk/2/hi/americas/7248995.stm

[glenc]

"...The US military has said it hopes to smash the satellite as soon as next week - just before it enters Earth's atmosphere - with a single missile fired from a US Navy cruiser in the northern Pacific Ocean.
The US has told Australia and a handful of other nations to be on standby for falling debris from the highly classified satellite, because there is a minute possibility of the strike misfiring and debris falling on land rather than water..."
http://news.smh.com.au/australia-prepares-for-falling-satellite/20080218-1sse.html

Here is the orbit data.
http://www.heavens-above.com/orbitdisplay.asp?satid=29651

[Phil]

does anyone no when they are going smash this thing up. Date and time.
Phil

[snowyskiesau]

According to Satobs, an aviation warning has been issued for an area near Hawaii for several hours during which time, USA193 will be passing overhead. It's believed that this is when it will be shot down.

http://www.satobs.org/seesat/Feb-2008/0337.html

Plot of orbit and are of interest:

http://satobs.org/seesat_ref/06057A/USA_193_NOTAM_unverified.pdf

[citivolus]

Attached is the orbit immediately following the intercept attempt. Note that it does not include whatever vector will be imparted by the intercept if it is successful (or even potential orbital shift if it is unsuccessful).

Notable areas it passes over are Vancouver Island, Alberta just north of Edmonton, and Adelaide. However, given the shape of the NOTAMS area, the missile will likely be launched to the North West, imparting a slight sideways motion after impact, which I would speculate would shift the orbit to be a bit more polar. I guess it really depends on if it is strictly kinetic, and the velocities involved at the time. I am no specialist on the subject, but have alerted my friends and family who live under the re-entry path to go out and have a look.

[glenc]

Here is some more info:
http://www.skyandtelescope.com/news/15715337.html

[Suzy_A]

A few people were on about nuclear-powered satellites and that reminded me of an ad that I saw in an old Scientific American, so here it is. It's from the August 1966 edition. The ad is for a 25 watt nuclear 'battery' that weighs 3000 pounds (mostly shielding) and a guaranteed life of 5 years per fuelling. Obviously, without the shielding it would only be a few pounds. The cost is $63,320. For comparison, there is another ad in the SA for an E-type Jag and that is about $6000.

It works by using isotope(s) that generate heat and then thermocouples to generate the electricity.

I think I'll buy one and run my 'scope mount on it - don't have to worry anymore about carrying around heavy lead-acids batteries that go flat all the time!

[citivolus]

There is some very useful information here regarding the NOTAMs as issued and interceptor re-entry:

http://www.zarya.info/Tracking/USA193/USA193.php


Note that a second NOTAM has been issued for the day after the first, which would cover a second attempt if the first fails for some reason:

[Kal]

The pentagon has said that it has sucessfully fired the missie and struck the satellite:

http://news.smh.com.au/us-missile-hits-spy-satellite-pentagon/20080221-1tju.html

[citivolus]

The first Australian pass starts in about 14 minutes, over Adelaide. I don't know if anything large enough to be daylight visible will be entering yet, but it may be worth a look.

[glenc]

Here is some more news: http://news.bbc.co.uk/2/hi/science/nature/7254540.stm

[rogerco]

I must be the last person to hear about this, no TV for the last few nights.

Can someone tell me? Did they just hit it and the impact force broke it up or did they explode something? Its just I though a conventional explosion would require oxygen? So did they hit it with a small nuclear shell, which I think is against some treaty or other.

Roger

[Kal]

The satellite was travelling at more than 20,000 km/h so they didn't need a warhead, just the kinetic energy from the collision would be enough to detroy it

[fringe_dweller]

this via meteorobs group

'Taken from the Satobs list, quoting in turn a message taken from the RASC list:

http://www.satobs.org/seesat/Feb-2008/0450.html

A message posted on the mailing list of the Royal Astronomical Society of
Canada says in part:

at approx. 19:43 PDT while observing the lunar eclipse at the PGAO (53 45'
29" N 122 50' 56" W) a group of
about 30 people, PG Centre members and public, witnessed what we assume was
the demise of the spy
satellite USA 193.

Many debris trails were witnessed moving from south-west to north-east at
high altitude. One was especially
bright and long lasting. I can recall about 6 bright trails and 15 fainter
ones.

The debris trails seemed to come in "waves" with the first wave being
brighter than the debris that followed
behind it. The trails seemed to be in a fan shape with the trails being
wider apart in the north-east than they
were in the south-est.

Brian Battersby, Prince George Centre RASC

- Marco

-----
Dr Marco Langbroek - SatTrackCam Leiden, the Netherlands.'

[Outbackmanyep]

Sure it wasn't "Percy" the Taiwanese made UK satellite from "Supernova" ?? hehe

[glenc]

The US is confident that its shooting down of a disabled spy satellite with a missile managed to destroy its potentially toxic fuel tank. Marine Gen James Cartwright said there was a 80-90% chance that the satellite's tank had been destroyed.
A fire ball, vapour cloud and spectral analysis indicating the presence of hydrazine all indicated that the tank had been hit, he told reporters.
The operation has been criticised by China and Russia.
"We're very confident that we hit the satellite," Gen Cartwright said at a Pentagon briefing hours after the missile was fired.
"We also have a high degree of confidence that we got the tank."...
http://news.bbc.co.uk/2/hi/americas/7256741.stm

[gaa_ian]

This has been an Amazing Story to watch unfold to its ultimate climax. No wonder the Russians and Chinese are a bit unsettled !
It would have been great to be with the RASC group seeing the debris burn up !

[snowyskiesau]

Here's a DOD clip of the satellite's final moments.

http://www.dodvclips.mil/?&fr_story=FRdamp250959&referer=http%3A%2F%2Fwww.news.com.a u%2Fstory%2F0%2C23599%2C23258003-2%2C00.html&autoplay=true&skin=oneclip&rf=ev

[gaa_ian]

That is very cool Geoff !
It was front page news here yesterday in the NT as some of the debris could land here !
http://www.ntnews.com.au/article/2008/02/22/3421_ntnews.html

[glenc]

http://celestrak.com/events/usa-193.asp
Assuming this information is correct and using the same approach as applied to the analysis of the orbital debris of from the Chinese ASAT test (http://celestrak.com/events/asat.asp), we obtain the following chart. It shows the percent of the 169 objects which decay over time (at least 59 of which are reported to have already decayed), based on our analysis. The black line represents 10-cm objects and the blue line represents 20-cm objects. In the 10-cm case, the last object decays 67 days after the intercept; in the 20-cm case, the last object decays 113 days after the intercept.

[citivolus]

Yes, I was very amused by that chart, especially in light of the quotes floating around in articles shortly after the press conference in which the intercept attempts were announced, where in some cases it was claimed that 50% of objects would re-enter within the first half orbit.