Posted on 10/01/2011 1:29:05 PM PDT by Evil Slayer
The world was gripped by the Nasa UARS satellite that fell back to Earth last Saturday – and now there’s another that’s plummeting back from orbit.
In late October or early November a Germany astronomy satellite – called ROSAT- will plunge uncontrolled back to Earth.
While slightly smaller than UARS, the German satellite is expected to have more pieces survive re-entry. The German space agency estimated that it has a 1-in-2000 chance of hitting someone - higher than the 1-in-3,200 odds NASA gave for UARS.
The German ROSAT satellite was launched in 1990, 'died' in 1998 and weighs two and a half tonnes.
The German space agency estimates that 30 pieces weighing less than two tons will survive re-entry. Debris may include sharp mirror shards.
The German space agency puts the odds of somebody somewhere on Earth being hurt by its satellite at 1-in-2,000 — a slightly higher level of risk than was calculated for the Nasa satellite.
Again, it seems certain that information on when - or where - the satellite might land will be scant.
But any one individual's odds of being struck are 1-in-14trillion.
Heiner Klinkrad, head of the Space Debris Office at the European Space Agency, said in a webcast posted on the German Aerospace Center's website: ‘It is not possible to accurately predict ROSAT's re-entry.
‘The uncertainty will decrease as the moment of re-entry approaches. It will not be possible to make any kind of reliable forecast about where the satellite will actually come down until about one or two hours before the fact.’
Experts believe that two dozen metal pieces from the bus-sized Nasa satellite fell over a 500-mile span in the Pacific Ocean.
It began hitting the water southwest of Christmas Island.
(Excerpt) Read more at dailymail.co.uk ...
the Germans just build stuff better...that’s why more pieces will survive reentry.
There will always be comm problems and things like that, but the satellite end of life and deorbit should also be part of the design.
Just an old country boy that is still amazed at what we do in space. /smile
Ach du lieber!!!
Do these numbers seem incompatibly to anyone else?
7 billion in world times 2000 = 14 trillion.
Message to Ted Thornhill: If an event is more likely to happen, THE ODDS ARE LOWER.....
Less likely to occur, ODDS ARE HIGHER........
Stay away from Vegas, Teddy Boy!
That is true for newer satellites. This must be an older one.
good point..
“Ach du lieber!!!”
Ist das nicht ein Satellit?
Ja! Das ist ein Satellit!”
Actually, it’s probably more complicated than that, because there’s no reason that just one person is hit, in that one in 2,000 chance event.
Just to illustrate what I mean, suppose that the odds of a second person being hit, at the same time, are 1 in 5. That would increase the chance of any particular individual being hit, by about 20% — to about one in 11.2 trillion. There is also some (small) chance that a chunk would take out (say) an airliner — thus further increasing the chance of an individual getting killed by the debris (even if not directly hit).
Thanks for the info update. I was a lot younger when Sputnik was launched. At that time I suspect very few people expected that what we now have in orbit could become a reality.
I agree that the odds seem to be based on an even distribution of population when we are in fact clustered. So that if one person is hit its likely that others would be hit.
However, if the number was adjusted to for clusters the chances of one person getting hit would be lower but the chances of multiple people getting hit from one debris would increase. I’m not enough of a math person to say the corrections would make the odds the same but my instincts tell me they would be near enough that the correct answer would be materially the same.
The world was gripped??
I wasn’t gripped.
Was anone else gripped? Did anyone go to their basment?
The picture of the satellite in post #1 makes it look like an air conditioning unit with wings and a jet engine.
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