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Defunct Satellite To Fall From the Sky
Front page first-timer EmLomBeeNo sends word of a 6.5-ton satellite that will soon be making a quick and fiery return to Earth. From Space.com:
"The huge Upper Atmosphere Research Satellite (UARS) is expected to re-enter Earth's atmosphere in an uncontrolled fall in late September or early October. Much of the spacecraft is expected to burn up during re-entry, but some pieces are expected to make it intact to the ground, NASA officials said. The U.S. space agency will be taking measures to inform the public about the pieces of the spacecraft that are expected to survive re-entry."
According to a NASA press conference today, you have a 1-in-21 trillion chance of being hit by falling debris. Who's feeling lucky?
Every day idiots all over the U.S. throw down $1 for a 1 in 100 million chance of winning some big jackpot lottery. So, on the off chance that said idiots stumble upon a news channel while channel-surfing between "The Jersey Shore" and Maury Povich's "Primetime Baby-Daddy Special" (and assuming that they're not too high to understand what's being said), there is a pretty good chance that they'll completely ignore the "1-in-21 trillion chance" addendum and only hear the "being hit by falling debris" part. In this case, I would say the odds of them panicking, and then going out and spending the last bit of their McDonalds paychecks on booze and "Huffers Own"-brand industrial glue are pretty goddamn high.
SJW: Someone who has run out of real oppression, and has to fake it.
uncontrolled fall
There's a reason why engineers shouldn't write press releases.
Really?
How?
In Liberty, Rene
So, does that mean there's actually a 1:3000 chance that someone on Earth will be struck? :)
So apparently they used the remaining fuel a few years ago to move it into a more rapidly decaying orbit. If they had enough fuel to do that why not just deorbit the whole thing in a controlled fashion and aim it at an ocean? We've done that before. Obviously these are some very smart people but it seems weird that they'd have exactly enough fuel to put it into a rapidly decaying orbit but not enough fuel to handle that last little bit.
On the bright side, the danger from deorbiting satellites is pretty small. The biggest actual problem that has occurred when a Soviet satellite with radioactive material decided to scatter itself over a large part of Canada back in the 1970s http://en.wikipedia.org/wiki/Kosmos_954. When the US space station Skylab pulled a similar stunt over Australia, the local government fined NASA a few hundred dollars for littering.
Back of envelope calculation shows me they're saying there's a 1 in 3000 chance of some person getting hit somewhere. Or am I holding it wrong?
there millon-to-one chances happens 9 of 10 times. But as this is world maybe 1 in 21 trillions is the right spot that turns it into something certain.
... it could be another Skylab (what a waste!) with a trajectory that drops it over, say, Europe instead of the Aussie outback.
Could my family sue NASA for damages caused by negligance?
Didn't you ever see one of those cartoons where Wile E. Coyote tries to trick Roadrunner into eating iron shot so that he can then use a giant horseshoe magnet mounted on a car to catch him, but then somehow Wile E. Coyote ends up eating the shot and getting dragged all over the desert running into cacti as the car with the magnet careens uncontrollably about?
It's just like that.
That simple calculation doesn't consider geographic clustering of people. Since many people are clustered in large population centers that are outside of the predicted possible impact locations, you shouldn't include the entire world population in the reduction of personal odds to generalized odds. For instance, if it is predicted to impact the southern hemisphere, you could rule out all people except those on the African, South American, and Australian continents and islands south of the the equator.
Make everything as simple as possible, but not simpler. - Albert Einstein
NASA says run, but not in a straight line.
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Not sure how many are fans of dead like me, but the simple fact that she got nailed by a toilet seat comes to mind with this story.
Just be careful not to get hit, as you will be nicknamed toilet seat girl/boy for the remainder of your unlife.
Is this the same NASA that thought there was a 1-in-100,000 chance of a catastrophic Shuttle failure?
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Interestingly the Ministry of Aviation in England did a study on something similar a while ago: http://aerade.cranfield.ac.uk/ara/arc/rm/3332.pdf. They claim that attitude deviations of up to 1.5 degrees may be observed for a 3 square metre surface area (normal to the Solar radiation) and a 2.5T satellite. That's not insignificant, and if the Sun did somehow produce a sudden large outburst, akin to a cataclysmic variable, then perhaps it might be enough to push the satellites into a decaying orbit. Then again, there are a lot of integrals in that paper and I could be reading it wrong!
How do they come up with that number? does that mean there are 21 trillion square whatevers of land that someone could possibly be standing? What if you are on a boat? what if you and 5 friends are on a boat is your boat 5 times more likely to get hit? WE NEED THESE DETAILS!
Although note that attitude deviation is a rotational thing (whoops, should have noticed that) - the calculations are essentially to work out the torque on the satellite, not the change in orbit height. In which case it may well be very insignificant.
Gotta have that funct!
Hehhe, amazing what 1 little letter can do.
(If at first you don't succeed, do it different next time!)
I hope Taco Bell puts up a target that, if hit, means everyone in the world gets a free burrito. They did it when Skylab came down.
Furries make the internet go.
Umm, you are off by about 3 orders of magnitude... hint: there are not 7 trillion people on the earth.
Look at it this way. The number of meteorites that reach the surface of the earth is estimated at more than one per day. Most of them are very small, but none of them would fail to get your attention if they hit you. How many impacts on humans do you know of?
rj
No, it does not mean 1 in 3 chance someone is going to be hit, even by the wildest stretch of the imagination.
1 in 21 trillion is 4.7619047619047619047619047619048e-14
If we assume a world population of about 7 billion, and we fudge the math as 4.7619047619047619047619047619048e-14 * 7 billion, we get 1 in 3000 chance someone gets hit. I can only assume that you assumed a 7 trillion population and used this same incorrect math.
It is going to be a lot less than that in reality, but I can't be arsed to do the math at the moment.
If there's a 1 in 21 trillion chance that an individual will be hit, and there are 7 billion people, then the odds of someone, somewhere, getting hit are 21,000,000,000,000/7,000,000,000 or 1 in 3,000.
Of course, seeing as people tend to clump together, the most likely scenario, IF someone gets hit, is that multiple people get hit - so that is also ~ 1 in 3,000.
This matches pretty well with the actual odds in the article:
A 300-pound piece of flaming satellite debris traveling at supersonic speeds is going to do more than hurt a little.
So, given that this happens every year, the odds of someone, somewhere getting hit during your lifetime are actually much better - if you only live to 50, they become 1 in 64.
Also, it's already happened that someone has been hit, even though the woman wasn't hurt, so the odds may be higher than "theory" alone predicts.
Ellen Muth is worried about this.
For those of you who won't get this joke:
http://en.wikipedia.org/wiki/Dead_Like_Me
If telephones are outlawed, then only outlaws will have telephones.
Yeah, I'm aware of those effects, as well as atmospheric extent expansion and contraction. That WILL affect satellites in the long run, but I can't see a major solar flare or CME causing it to rain debris all of a sudden.
In Liberty, Rene
This might help you figure it out, or it may just confuse you further.
http://en.wikipedia.org/wiki/Orbits
Don't know something? Look it up. Still don't know? Then ask.
Hence why I suggested unless it was an outburst on the scale of a cataclysmic variable - in which case we're all dead then anyway, probably before the satellites fall on our heads.
How they say in the article that the satellite remains US property. Yeah okay, if their junk lands in my backyard (Canada) I think I'll keep it. Seriously how are they going to enforce that if it lands somewhere not in the US? I'm sorry but if your junk lands on some other countries soil they can do with it as they please.
I think that you would probably stay up there longer than it (the ISS) would.
Given tthat they are planning to deorbit it in a decade or so anyway.
And you can improve on that quite a bit. Just go down to the local surplus store, buy some satellite spare parts and drop them on your house.
The odds of one house being hit by two pieces of satellite is vanishingly small.
Have gnu, will travel.
Then the odds of getting hit by a piece of the satellite are the odds that a piece will hit near enough to you that you can grab it and keep it as a trophy of improbably odds.
- Holy crap, I've got MOD points! Who thought that was a good idea.
It's still right on average. Any increase in probability due to clustering of population in one place is accompanied with a decrease in probability elsewhere on the planet due to rarefaction of population.
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all i can say is that I'm glad i'm not a girl named George.
Or a boy named Sue.
In the first link in the summary, there are two images of the satellite--one against a backdrop of Earth and attached to a Space Shuttle manipulation boom. The next image is labeled as being the same thing except against a backdrop of deep space.
If so, then why are there clearly a wall, window and door in the darkened background of the second image? It appears to be a mock-up, or even possibly a scale-model, held in the air by the boom.
Mislabeled image, or is this a "Capricorn One" moment?
Image:
http://i.space.com/images/i/11938/i02/uars-satellite-deployment.jpg?1315422763
Always take your umbrella with you.
nope, sometimes can get a "skip re-entry". that can change orbital inclination under some conditions. for the shuttle orbiter, up to 0.8 degrees change was possible.