Friday, September 23, 2011

I Guess We'll Just See, Won't We?

Updated at 10:15 AM, Sept. 24

Updated at 1:20 AM, Sept. 24

Caption: The Upper Atmosphere Research Satellite (UARS), in a happier 3D orbital simulation time.

Image credit: NASA

Apparently, a six ton piece of space junk is headed back to Earth this evening:
NASA has adjusted the prediction for when and where its defunct climate satellite will fall to earth, moving the potential window of re-entry from Friday afternoon to “late Friday, Sept. 23, or early Saturday, Sept. 24” ET.

Even more surprising: After noting on Thursday that the satellite wasn’t expected to be over North America at all during it’s re-entry window, NASA has since revised that call, now saying “There is a low probability any debris that survives re-entry will land in the United States, but the possibility cannot be discounted because of this changing rate of descent.”

NASA Satellite Changes Course, Re-Entry Could Occur Friday or Saturday Over U.S.
Some two dozen chunks of it are expected to hit the ground. The heaviest weighs about three hundred pounds:
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).

Huge Defunct Satellite Falling to Earth Faster Than Expected, NASA Says
Well, that's good. I'd hate to think there would be pollution or something. Still NASA advises that anyone who encounters a piece of this satellite after it's fallen not to touch it. That's probably a good idea. Call local law enforcement, we're told.

NASA's latest prediction, as of 4:30 PM Pacific time, is that it will fall somewhere in Canada, Africa, Australia, or the oceans nearby.

It would be nice, I sometimes think, if maybe we had some way of stopping this sort of thing from happening, at least when it might hit populated areas. Here's just one reason I'm thinking that, which is the latest prediction graphic from the Aerospace Corporation:
Image credit Aerospace Corporation

Yes, NASA and a leading aerospace contractor are running competing predictions right now. That yellow satellite symbol is where the Aerospace Corporation expects it to crash. The tick marks on the yellow lines afterward are where it would be at five minute intervals thereafter if it kept flying. See where it's going to be fifteen minutes later?

I hope my roof can handle a three-hundred pound chunk of metal for a while.

So, we'll see whether it ends up in the North Pacific, in the Canadian wilderness, or some unmentioned place in between.

Did I mention I think it would be nice if we had the ability to prevent this sort of thing?

UPDATE (1:20 AM PDT, Sept. 24): As of about thirty minutes ago, NASA was sure the satellite had come down somewhere:
Update #15
Sat, 24 Sep 2011 12:46:42 AM PST

NASA’s decommissioned Upper Atmosphere Research Satellite fell back to Earth between 11:23 p.m. EDT Friday, Sept. 23 and 1:09 a.m. EDT Sept. 24. The Joint Space Operations Center at Vandenberg Air Force Base in California said the satellite penetrated the atmosphere over the Pacific Ocean. The precise re-entry time and location are not yet known with certainty.
I suspect this means it didn't hit any populated areas. Looks like maybe Aerospace Corp. won the bet. All I know for sure is that I haven't heard or seen anything crashing to Earth.

UPDATE 2 (Sept. 24): Looks like AC won the bet:
Update #16

Sat, 24 Sep 2011 08:37:25 AM PST

NASA’s decommissioned Upper Atmosphere Research Satellite fell back to Earth between 11:23 p.m. EDT Friday, Sept. 23 and 1:09 a.m. EDT Sept. 24. The Joint Space Operations Center at Vandenberg Air Force Base in California said the satellite entered the atmosphere over the North Pacific Ocean, off the west coast of the United States. The precise re-entry time and location of any debris impacts are still being determined. NASA is not aware of any reports of injury or property damage.
I wonder what they won?


2 comments:

James Ala said...

The smart money is always with the Pacific Ocean Cujo359. With the planet being nearly three quarters water, and with the Pacific being the biggest, badest patch of blue out there, odds are space junk will splash down in the Pacific Ocean. Granted you do have the odd piece of rock crunching into the AZ desert, or a dinosaur-killing object ripping into the Gulf of Mexico but those are rarer incidents.

Cujo359 said...

True, but the area it landed in was pretty close to where AC predicted. I'll give them credit for that one.