Author Topic: Upper Atmosphere Research Satellite (UARS) - Re-entry  (Read 146136 times)

Offline Greg906

  • Member
  • Posts: 15
  • Liked: 5
  • Likes Given: 18
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #40 on: 09/18/2011 10:31 pm »
"As of Sept. 16, 2011, the orbit of UARS was 140 mi by 155 mi (225 km by 250 km).

Wow...Heavens Above now lists it as 216 x 238 km, 56.9° (Epoch Sep 18).

Heh just looked it up on Heavens Above too. Now that it is no longer cloudy. The next good pass over where I live is going to be the 25th. Looks like I might not get a chance to say good bye. Its is saying 0.9 mag though. It should be bright for anyone who can see it. Has anyone got a chance to see it lately?

I saw it this morning at 6:02 am (Eastern US) from Michigan's Upper Peninsula.

Heaven's Above perfectly nailed the times--appeared within just a second or two of prediction moving into the eastern sky.  I couldn't check the predicted brightness of 0.7 mag b/c of a very bright moon overhead.  But I can safely say it was bright enough to stand out!

FWIW - perhaps a trick of the light, but I thought it flared for a moment brighter?

...long, long, time lurker, first time poster!

Offline ginahoy

  • Full Member
  • *
  • Posts: 160
  • Liked: 5
  • Likes Given: 1
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #41 on: 09/19/2011 05:05 am »
UARS passes directly over me (87d) on Tuesday morning... sorta glad that pass isn't happening a few days later = :-o

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39271
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #42 on: 09/19/2011 04:05 pm »
UARS passes directly over me (87d) on Tuesday morning... sorta glad that pass isn't happening a few days later = :-o
Why not? You could get a pretty good souvenir! ;)
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline notsorandom

  • Full Member
  • ****
  • Posts: 1740
  • Ohio
  • Liked: 438
  • Likes Given: 91
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #43 on: 09/19/2011 05:48 pm »
"As of Sept. 16, 2011, the orbit of UARS was 140 mi by 155 mi (225 km by 250 km).

Wow...Heavens Above now lists it as 216 x 238 km, 56.9° (Epoch Sep 18).

Heh just looked it up on Heavens Above too. Now that it is no longer cloudy. The next good pass over where I live is going to be the 25th. Looks like I might not get a chance to say good bye. Its is saying 0.9 mag though. It should be bright for anyone who can see it. Has anyone got a chance to see it lately?

I saw it this morning at 6:02 am (Eastern US) from Michigan's Upper Peninsula.

Heaven's Above perfectly nailed the times--appeared within just a second or two of prediction moving into the eastern sky.  I couldn't check the predicted brightness of 0.7 mag b/c of a very bright moon overhead.  But I can safely say it was bright enough to stand out!

FWIW - perhaps a trick of the light, but I thought it flared for a moment brighter?

...long, long, time lurker, first time poster!
Hi Greg welcome to the board! UARS likely tumbling so you might have seen a flare. Flaring has been reported in that past for UARS when it was under attitude control. Good to know that Heavens Above is able to predict the pass timing so well. I had been wondering about that since its orbit is changing so rapidly now.

Offline ginahoy

  • Full Member
  • *
  • Posts: 160
  • Liked: 5
  • Likes Given: 1

Offline anik

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 7776
  • Liked: 955
  • Likes Given: 368
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #45 on: 09/19/2011 07:42 pm »
For your information, on September 19th the Russian Space Forces have told that UARS fragments will fall into the Indian Ocean (40 S, 54 E) on September 23rd.

Offline Lee Jay

  • Elite Veteran
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8566
  • Liked: 3603
  • Likes Given: 327
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #46 on: 09/19/2011 07:45 pm »
"As of Sept. 16, 2011, the orbit of UARS was 140 mi by 155 mi (225 km by 250 km).

Wow...Heavens Above now lists it as 216 x 238 km, 56.9° (Epoch Sep 18).

211 x 232 km, 56.9° (Epoch Sep 19)

Dropping like a rock!

Offline rdale

  • Assistant to the Chief Meteorologist
  • Senior Member
  • *****
  • Posts: 10390
  • Lansing MI
  • Liked: 1415
  • Likes Given: 171
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #47 on: 09/19/2011 07:52 pm »
Can someone decipher the 1:3200 casualty risk number that is being claimed? 1 out of every 3200 people on the planet getting hit seems a little tough to correlate...

Offline Lee Jay

  • Elite Veteran
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8566
  • Liked: 3603
  • Likes Given: 327
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #48 on: 09/19/2011 07:54 pm »
Can someone decipher the 1:3200 casualty risk number that is being claimed? 1 out of every 3200 people on the planet getting hit seems a little tough to correlate...

I thought it was a 1 in 3200 chance of someone getting hit and injured by falling debris.
« Last Edit: 09/19/2011 07:55 pm by Lee Jay »

Offline ginahoy

  • Full Member
  • *
  • Posts: 160
  • Liked: 5
  • Likes Given: 1
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #49 on: 09/19/2011 07:55 pm »
I think that means 1 out of 3200 chance that there will be one or more casualties.

Offline rdale

  • Assistant to the Chief Meteorologist
  • Senior Member
  • *****
  • Posts: 10390
  • Lansing MI
  • Liked: 1415
  • Likes Given: 171
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #50 on: 09/19/2011 07:56 pm »
Gotcha, I didn't see much detail in the NASA presentation either other than that number. THanks for clarifying...

Offline Prober

  • Senior Member
  • *****
  • Posts: 10348
  • Save the spin....I'm keeping you honest!
  • Nevada
  • Liked: 721
  • Likes Given: 729
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #51 on: 09/19/2011 11:24 pm »
"As of Sept. 16, 2011, the orbit of UARS was 140 mi by 155 mi (225 km by 250 km).

Wow...Heavens Above now lists it as 216 x 238 km, 56.9° (Epoch Sep 18).

211 x 232 km, 56.9° (Epoch Sep 19)

Dropping like a rock!

Was any talk some time ago about firing a device to break up the Sat into smaller pieces?

Know it was done before.
2017 - Everything Old is New Again.
"I fear all we have done is to awaken a sleeping giant..." --Isoroku Yamamoto

Offline darcy at ceduna

  • Member
  • Posts: 2
  • Ceduna, South Australia
    • Facebook Darcy O'Shea
  • Liked: 0
  • Likes Given: 0
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #52 on: 09/20/2011 10:00 am »
Visible pass of UARS over Ceduna, South Australia on Saturday, 17 Sep 2011 at 1909.  Track from heavens Above was spot on.  It races across the sky.
I was in Ceduna when Skylab crashed into the desert in Western Australia.



Nikon D50 Tamron AF55-200 (ISO400 55m f/8 21.2 secs)
astrophotography - its a matter of timing and a $96 tripod

Offline JohnFornaro

  • Not an expert
  • Senior Member
  • *****
  • Posts: 10974
  • Delta-t is an important metric.
  • Planet Eaarth
    • Design / Program Associates
  • Liked: 1257
  • Likes Given: 724
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #53 on: 09/20/2011 01:29 pm »
The WaPo had an article about this yesterday.  About the "landing" zone:  The article observed that if you were in the Arctic or in Antarctica, you'd have nothing to fear.  Also gave odds of a piece hitting someone as one in 3200, which I thought were pretty high odds.

Since they're disposing of it anyhow, and it's already been whacked by a meteor, just wondering:  If you had the means to retrieve it and "part it out" on ebay, you couldn't could you?

Recently a small meteor crashed thru the roof of a doctor's clinic, somewhere in Northern Virginia, IIRC.  The doctor and the landlord got into a legal tussle about who "owned" the meteorite fragment that survived.
Sometimes I just flat out don't get it.

Offline rdale

  • Assistant to the Chief Meteorologist
  • Senior Member
  • *****
  • Posts: 10390
  • Lansing MI
  • Liked: 1415
  • Likes Given: 171
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #54 on: 09/20/2011 01:53 pm »
Also gave odds of a piece hitting someone as one in 3200, which I thought were pretty high odds.

Apparently you missed the explanation of the odds just a few posts above :)

Offline Lee Jay

  • Elite Veteran
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8566
  • Liked: 3603
  • Likes Given: 327
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #55 on: 09/20/2011 01:58 pm »
"As of Sept. 16, 2011, the orbit of UARS was 140 mi by 155 mi (225 km by 250 km).

Wow...Heavens Above now lists it as 216 x 238 km, 56.9° (Epoch Sep 18).

211 x 232 km, 56.9° (Epoch Sep 19)


205 x 223 km, 56.9° (Epoch Sep 20)

Apogee is dropping faster than perigee.  Odd that that confusing orbital mechanics stuff actually works....

Offline Space Pete

Apogee is dropping faster than perigee.  Odd that that confusing orbital mechanics stuff actually works....

This occurs since atmospheric resistance increases at perigee, and so apogee will decrease more than perigee will decrease when UARS is at apogee.

At least, that's my understanding... ;)
NASASpaceflight ISS Editor

Offline holosys

  • Member
  • Posts: 13
  • Liked: 0
  • Likes Given: 0
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #57 on: 09/20/2011 05:22 pm »
Let me do a reality check on my understanding of our current technological capabilities regarding this satellite, see if I can get a "Yay" or "Nay" from knowledgeable forum members as to whether I'm right or wrong, and as the frosting on the cake, get an explanation as to WHY I'm right or wrong. Here goes:

A satellite with its largest frag weighing 300 lbs (about the size of my 1999 42" Sony Trinitron, a monster I thought would fall through the floor after 3 guys carried it in to the master bedroom) is falling like a rock. That part I get.

NASA's illustrious technology has narrowed down its impact area -- NOT somewhere in a geographic region like California where I live; NOT somewhere in North or South America -- but somewhere on Earth (except north or south of 57 latitude, which means those near the north or south poles can lower their stress levels).

Probability means NOTHING to me because I'm one of those strange blokes who seem to keep experiencing improbable events year after year, when I passed age fifty in the late 00's one would figure I deserved a reprieve from these annoying laws. But no, probability is not through showing off for me, go figure.

So you tell me an object the size of my Sony Trinitron and weighing as much could go crashing through my roof, where I have some sweet little birdies singing to rain forest songs, classical music (they love Beethoven and Mozart) and dancing to rock music from an MP3 player. It's not a nice vision to come home to this coming Friday. I know, Donnie Darko is a sci-fi romp into the dark laws of improbabilities (and scientists probably find it silly), and my life experiences when it comes to probability are subjective at best (a word my dad who worked at NASA on the Moon landing in 1969 loved, ooh, such an important law when it comes to life support systems, maintaining living conditions, and all the "outliers" that could spoil the party).

However, to quickly conclude as I've talked too much, I simply don't like thinking technology can narrow down the trajectory of a falling object that could maim or kill life on a planet's surface to........ a surface area, what, about 3/4's of that planet's surface?

Tell me it ain't so, NASA, that you can at least narrow it down to, say, North America? More specifics would even be more encouraging.

Don't worry, I can take flames, but answers are even more impressive. :)

Thanks.

Online ugordan

  • Senior Member
  • *****
  • Posts: 8520
    • My mainly Cassini image gallery
  • Liked: 3543
  • Likes Given: 759
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #58 on: 09/20/2011 05:27 pm »
Tell me it ain't so, NASA, that you can at least narrow it down to, say, North America? More specifics would even be more encouraging.

Think of it as trying to forecast weather a month in advance. As predicted time of reentry becomes closer, the actual ground area will become more constrained. The uncertainty is still too high at this point.

Offline tminus9

  • Full Member
  • *
  • Posts: 145
  • Liked: 8
  • Likes Given: 1
Re: Upper Atmosphere Research Satellite (UARS) - Re-entry
« Reply #59 on: 09/20/2011 05:35 pm »
Tell me it ain't so, NASA, that you can at least narrow it down to, say, North America? More specifics would even be more encouraging.

Think of it as trying to forecast weather a month in advance. As predicted time of reentry becomes closer, the actual ground area will become more constrained. The uncertainty is still too high at this point.

Even with the last prediction (two hours prior), the uncertainty along the ground track will be on the order of 7,500 miles.

Tags:
 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
1