(meteorobs) UARS Satellite expected to reenter atmosphere in 3-5 days

[Marco Langbroek]

You were more lucky than me Joe.

Tried to watch a low 20 degrees pass under Orion here in the early morning (5:50 
am local time), but an untimely patch of clouds intervened. No observable passes 
the next days (ignoring passes only 4 degrees over the horizon...).

Tumbling behaviour has been reported by other observers lately (satellite 
observer and BWGS chair Bram Dorreman in Belgium in August).

> then a
> relatively low evening pass is set for Saturday at around 7:40 p.m.
>(if it's still in orbit).

I strongly doubt it will. Decay time predictions are increasingly moving forward 
in time and I don't think it will last beyond 23 September.

- Marco




Op 19-9-2011 16:56, Skywayinc at aol.com schreef:
> Set my alarm and got up early this morning to view a predicted
> near-overhead pass of the UARS satellite over my home in
> Putnam Valley, NY.
> The NW to SE pass came pretty much on schedule between
> 5:47 and 5:50 a.m. (according to Heavens-Above). As expected,
> movement was quite rapid . . . it streaked across the sky much
> quicker than the ISS or the Space Shuttle.
> During the three or so minutes I had it in view, the satellite slowly
> rose in brightness from about magnitude 3 to 0, then suddenly
> flared/flashed in brightness to about -2 or -3, then quickly dropped
> off to near-invisibility. Then the whole sequence began anew. It
> did this a total of three times before it vanished behind the treetops
> in my southeast. The thing must be tumbling.
> There is another high pass scheduled for tomorrow morning . . .
> UARS will emerge from the Earth's shadow near its highest point
> in the sky of nearly 80-degrees at around 5:30 a.m., then a
> relatively low evening pass is set for Saturday at around 7:40 p.m.
> (if it's still in orbit).
> Unfortunately, a protracted spell of cloudy weather is expected
> to settle in tonight and last much of this week, so perhaps this
> morning was my last view. of UARS.
> -- joe rao
> In a message dated 9/19/2011 6:53:09 A.M. Eastern Daylight Time,
> meteoreye at comcast.net writes:
> Prepare for UFO and fireball reports!
> This will be an uncontrolled reentry, so could occur anywhere from 57 degrees N
> to 57 degrees South latitude.
> Latest estimate is Sept 23 +/- 1 day
> The risk assessment is interesting reading:
> http://www.nasa.gov/pdf/585584main_UARS_Status.pdf
> Total dry mass at start 5668 kg
> – Number of potentially hazardous objects expected to survive: 26
> – Total mass of objects expected to survive: 532 kg
> – Estimated human casualty risk (updated to 2011): ~ 1 in 3200
> • No NASA or USG human casualty reentry risk limits existed when UARS
> was designed, built, and launched.
> • NASA, the USG, and some foreign space agencies now seek to limit human
> casualty risks from reentering space objects to less than 1 in 10,000.
> • UARS is a moderate-sized space object. Uncontrolled reentries of objects
> more massive than UARS are not frequent, but neither are they unusual.
> – Combined Dragon mockup and Falcon 9 second stage reentry in June 2010 was more
> massive.
> • Since the beginning of the space age, there has been no confirmed report
> of an injury resulting from reentering space objects.
> • NASA, DoD, and the IADC will be monitoring the decay and reentry of UARS
> carefully.
>
>
>
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