UARS

Dead satellite likely fell into Pacific Ocean--maybe

NASA's decommissioned 6.3-ton Upper Atmosphere Research Satellite, out of gas and out of control after two decades in space, plunged back into the atmosphere early Saturday, heating up, breaking apart, and presumably showering chunks of debris along a 500-mile-long Pacific Ocean impact zone.

Maybe.

U.S. Strategic Command radar tracking indicated re-entry would occur around 12:16 a.m. EDT (GMT-4) Saturday as the satellite was descending across the Pacific Ocean on a southwest-to-northeast trajectory approaching Canada's west coast. If re-entry occurred on or before the predicted time, any wreckage that survived atmospheric heating almost certainly fell … Read more

Derelict NASA satellite falls back to Earth

NASA's Upper Atmosphere Research Satellite, out of gas and out of control after two decades in space, plunged back into the atmosphere early Saturday, heating up, breaking apart and presumably showering chunks of debris along a 500-mile-long downrange impact zone.

But NASA officials could not immediately confirm where or exactly when the satellite came down, saying only that re-entry occurred during a two-hour period.

"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 agency said in a … Read more

Track NASA's crashing satellite to avoid getting hit by space junk

The satellite that once confirmed the existence of a hole in the ozone layer is now tearing a new path across the sky in a final fiery descent back to Earth, and there's a chance it could hit you upside the head.

OK, so the chance that you'll get smacked with space junk this week is only about 1 in 20 trillion, but why risk it? You can track the Thelma and Louise-style ending of the Upper Atmospheric Research Satellite--or UARS for short--on your Android phone or tablet with an app called Satellite AR.

AGI--makers of the augmented reality app that also has the nifty ability to tell you what satellites are currently passing overhead by simply pointing your phone's camera at the sky--have added a temporary button to the app's menu to easily keep track of UARS' demise.

While the odds that you, specifically, will wind up in an involuntary boxing match with UARS are in the trillions, the chance that someone on Earth will be hit by a piece of the satellite is about 1 in 3,200--that's lower than the acceptable threshold of 1 in 10,000 that NASA adopted after UARS was launched.

Related story • Heads up! NASA satellite descends toward fiery doom… Read more

Heads up! NASA satellite descends toward fiery doom

NASA's decommissioned Upper Atmosphere Research Satellite, out of gas and out of control, is not descending toward re-entry as rapidly as expected, officials say, likely delaying the satellite's kamikaze plunge to Earth by a few hours, to late Friday or early Saturday.

Experts expect more than two dozen chunks of debris to survive re-entry and hit the ground in a 500-mile-long footprint somewhere along the satellite's orbital track. But given the bus-size 6.3-ton's satellite's trajectory and the vast areas of ocean and sparsely populated areas UARS passes over, experts say it is unlikely any … Read more

Patience, lots of luck needed to spot falling satellite

Armchair satellite trackers hoping to catch a glimpse of NASA's doomed Upper Atmosphere Research Satellite when it plunges back to Earth on Friday will need patience, access to the Internet, a clear sky, and a large helping of luck, experts say.

Even with last-minute updates from NASA and U.S. Strategic Command pinpointing when and where UARS will begin its final plunge, the sheer size of the planet, with its vast stretches of ocean and remote terrain, means the odds of catching a glimpse of the spacecraft's fiery demise--or of being anywhere near any falling debris--will be remote.

But as re-entry footage of the old Russian Mir space station and the more recent flaming fall of a European cargo craft show, satellite "decays" offer the public and experienced amateurs alike a chance to witness a fairly spectacular show.

The UARS re-entry "is nothing to be particularly worried about, and if you're very lucky and in the right place at the right time, you may see quite a nice little fireworks show from it. But it's highly improbable that you'll get even that much out of it," said Ted Molczan, a well-known satellite watcher whose computer analysis and predictions have helped sophisticated hobbyists around the world track down spy satellites and other challenging targets.

"You have to maintain reasonable expectations. And in this case, the right expectation is, 'I'm not going to see this.' On the other hand, if you stop there it becomes a self-fulfilling prophecy. So you do want to see it, you know you won't, but (if you make the effort) you might!"… Read more

NASA satellite soon to return to Earth... in pieces

Almost 20 years to the day after it was launched into space to collect data on Earth's atmosphere and interactions with the sun, NASA's Upper Atmosphere Research Satellite is coming back home--in pieces--and there's a higher than normal chance one of them will hit someone.

But before you run to grab your diamond and titanium alloy umbrella that I know you have somewhere in the back of the hall closet for just such an occasion, it's important to note that there's only a 1 in 21 trillion chance that a piece of the space junk will hit you specifically, according to an AP report. A NASA scientist apparently told the AP that there is a 1 in 3,200 chance that a piece of the satellite will hit someone on Earth, which is much higher than the 1 in 10,000 threshold NASA has adopted as an acceptable risk. That rule was put in place after the UARS satellite was launched in 1991.

CNET attempted to confirm the figure, but NASA's East Coast media headquarters is closed for the day. We've reached out through other channels, but did not immediately receive a response. I called U.S. Strategic Command at Vandenberg Air Force Base in California, which also houses the Joint Space Operations Center that "works around the clock detecting, identifying, and tracking all manmade objects in Earth orbit, including space junk," according to a NASA release.

A communications officer there told me that she believed NASA had worked with another agency to come up with a risk model for the UARS re-entry. NASA often uses software called--in typical NASA naming style--ORSAT, for Object Re-entry Survival Analysis Tool, to figure these sorts of things out.

Point is, NASA says in a posting on its Web site, there's a very small risk of a piece of UARS damaging anything or anyone.… Read more