A 'Heads-up" - literally

[Kathryn41 3,205]

http://www.smartplanet.com/blog/thinking-tech/falling-satellites-should-we-worry/8508 (good graphics)

and http://www.scientificamerican.com/article.cfm?id=huge-defunct-satellite (article)

Huge, Defunct Satellite Falling to Earth Faster than Expected, NASA says

NASA space junk experts have refined the forecast for the anticipated death plunge of a giant satellite, with the U.S. space agency

now predicting the 6 1/2-ton climate probe will plummet to Earth around Sept. 23, a day earlier than previously reported.

The defunct bus-size spacecraft is NASA's Upper Atmospheric Research Satellite (UARS), which launched in 1991 and was shut down in

2005 after completing its mission. The satellite was expected to fall to Earth sometime this year, with experts initially pegging a weeks-long

window between late September and early October, then narrowing it to the last week of this month.

That window, NASA now says, has been trimmed to just three days. "Re-entry is expected Sept. 23, plus or minus a day. The re-entry of

UARS is advancing because of a sharp increase in solar activity since the beginning of this week," NASA officials wrote in a status update

today (Sept. 16). The projection is a day earlier than a previous forecast released by NASA yesterday.

NASA spokeswoman Beth Dickey confirmed with SPACE.com earlier today that the reason UARS is expected to fall early in its re-entry window

is because of the sharp uptick in solar activity. Solar effects from the sun can create an extra drag on satellites in space because they can

heat the Earth's atmosphere, causing it to expand, agency officials have said.

Where will UARS fall?

But exactly where the UARS spacecraft will fall is still unknown. NASA expects at least 26 large pieces of the massive satellite to

survive the scorching temperatures of re-entry and reach Earth's surface. Titanium pieces and onboard tanks could be among that debris,

but the UARS satellite carries no toxic propellant (NASA used up all the fuel in 2005).

The debris is expected to fall over a swath of Earth about 500 miles (804 kilometers) long, NASA officials said. There is a 1-in-3,200

chance of satellite debris hitting a person on the ground, odds that NASA says are extremely remote. Outside experts agree.

"Look at how much of Earth is covered with water," Victoria Samson, the Washington Office Director of the Secure World

Foundation, an organization dedicated to the peaceful use of outer space, told SPACE.com this week. "There's a really good chance it's

going to go straight into the ocean."

Constant satellite watch

NASA officials expect the UARS satellite to fall over a region somewhere between the latitudes of northern Canada and southern South

America, which leaves a vast swath of the world open as a possible re-entry point. About 75 percent of the Earth's surface is

covered in water, which makes an ocean splashdown likely, NASA and experts have said.

NASA and the Joint Space Operations Center of U.S. Strategic Command at Vandenberg Air Force Base, Calif., are keeping a close watch

on the falling satellite, but will only be able to pinpoint its actual crash zone to within about 6,000 miles (10,000 km) about two hours before

re-entry.

As of Thursday, the UARS satellite was flying in an orbit of between 143 and 158 miles (230 to 255 km) above Earth. That orbit is dropping

lower each day, NASA officials said. NASA has advised the public not to touch any debris that may reach the surface, should it be discovered.

Instead, the space agency says that anyone who finds satellite debris should contact their local law enforcement agency.

The $750 million UARS mission was designed to measure ozone and other chemical compounds found in Earth's ozone layer in order to better

understand how the upper atmosphere affects our planet. It also recordedwind speeds and temperatures in the stratosphere, as well as the energy

Earth received from the sun.

[IR5FORMUMSIE 850]

Is this thing dangerous? You bet U-ARS!!!!

[spookyturtle 9,465]

I'm wearing a hard hat, just to be safe.

[Ban Hammer 13,334]

[IR5FORMUMSIE 850]

I'm wearing a hard hat, just to be safe.

I thought that you only did it bareback.

[MyLittlePony 340]

I hope it lands on my area i collect parts and sell them.

[Kathryn41 3,205]

The parts that get me are that it will fall somewhere between the latitudes of Northern Canada and Southern South America, and that they will only have about 2 hours notice where exactly that will be. That doesn't leave a heck of a lot of the planet out of the possible target area.

It would be kind of neat to see the space debris fall though. I remember seeing another piece of space trash fall to earth in a fireball about 10 years ago now, I think. It streaked across a good portion of the Canadian sky and burned up before it reached ground - pretty darn impressive!

[IR5FORMUMSIE 850]

The parts that get me are that it will fall somewhere between the latitudes of Northern Canada and Southern South America, and that they will only have about 2 hours notice where exactly that will be. That doesn't leave a heck of a lot of the planet out of the possible target area.

It would be kind of neat to see the space debris fall though. I remember seeing another piece of space trash fall to earth in a fireball about 10 years ago now, I think. It streaked across a good portion of the Canadian sky and burned up before it reached ground - pretty darn impressive!

As long as there isn't a repeat of the Tunguska event, it's all good.

[Ban Hammer 13,334]

and that they will only have about 2 hours notice where exactly that will be. That doesn't leave a heck of a lot of the planet out of the possible target area.

yeah i know! makes me afraid to go to sleep.

[IR5FORMUMSIE 850]

yeah i know! makes me afraid to go to sleep.

I thought that President Obama did that.

[spookyturtle 9,465]

Maybe it will land in Australia?

[Ban Hammer 13,334]

I thought that President Obama did that.

[IR5FORMUMSIE 850]

Maybe it will land in Australia?

It can't land in your messenger box since it's full, though not necessarily of vegemite. :devil:

[MyLittlePony 340]

Maybe it will land in my work area i can take the rest of day off.

[bigdog 376]

Old school, duck and cover.