News UARS about to fall from the sky

[CrimsonDoc]

Is there any way to find out what the orbital path data etc is, so its re-entry can be simulated in Orbiter?

Edit: Ooops! Just seen astrosammy's link in their post above

 

[Jarvitä]

Indeed, why such a big difference? I would expect the two odds to be the same.

Really? You'd expect the probability of it hitting one of 7 billion people to be the same as the probability of hitting a specific person? Why?

 

[orb]

CBS News Space: UARS Re-Entry Prediction Updates:

U.S. Strategic Command's current prediction for the UARS entry:

Report Date/Time: 2011-09-23 00:17:00 GMT
Predicted Decay Time: 2011-09-24 00:42:00 GMT +/- 15 Hours
Predicted Decay Location (altitude 10 km) : 46.1° S, 112.7° E
Direction: descending
Inclination: 56.9°
Revolution Number: 10917

{...}

It's in ocean.

 

[MattBaker]

+/- 15 Hours

Someone besides me thinks that these predictions are like bets?
You can say roughly what will happen, but your prediction could be messed up in a short period of time.

 

[garyw]

Really? You'd expect the probability of it hitting one of 7 billion people to be the same as the probability of hitting a specific person? Why?

Exactly. This 1 in 3,200 figure is benig widely misquoted. It's actually the chance of a piece of debris striking someone anywhere in the world and that, not surprisingly, is fairly high. After all, UARS orbit carries it over most of the populated world.

However, the chance that YOU as an individual person could get hit by a piece of UARS is much, much lower. You'd have to be in a very specific spot and a very specific time and as a good part of UARS orbit is over water you may also have to be in a boat........ :lol:

 

[agentgonzo]

Predicted Decay Time: 2011-09-24 00:42:00 GMT +/- 15 Hours
Predicted Decay Location (altitude 10 km) : 46.1° S, 112.7° E

It's in ocean.

Interesting that they give the decay time +/- 15 hours, but give the location as if it were exact, when a decay time of +10 minutes can equal thousands of miles... I say it could still land anywhere between 57N and 57S

 

[Artlav]

Interesting that they give the decay time +/- 15 hours, but give the location as if it were exact, when a decay time of +10 minutes can equal thousands of miles... I say it could still land anywhere between 57N and 57S

It's called periapsis. Or perigee, if you like.
And uncertainty is in the number of orbits.

 

[Urwumpe]

It isn't periapsis actually. It is the calculated point with simplified atmospheric model, in which the spacecraft would cross the 10 km altitude mark. It is almost falling straight down at that point.

Still, 15 hours are about 10 orbits and the ground track covers about 150° longitude of Earth in that time. +/- 15 hours means it can impact literally everywhere except in a small part of Earth that is 60° wide. You can exclude it reentering on its apoapsis passage, so luckily the zone is only half as big as it could be.

 

[T.Neo]

Please de-orbit your debris !! (in a controlled fashion) :facts:

I'm sorry, I just had to.

 

[agentgonzo]

You can exclude it reentering on its apoapsis passage, so luckily the zone is only half as big as it could be.

Not really, as the orbit will change so drastically during the last two-or-so orbits that what is currently its apogee is largely irrelevant to its trajectory in its final orbit. It could reenter anywhere on its current ground track.

 

[Urwumpe]

Not really, as the orbit will change so drastically during the last two-or-so orbits that what is currently its apogee is largely irrelevant to its trajectory in its final orbit. It could reenter anywhere on its current ground track.

Not really, the argument of periapsis simply changes strongly in that phase, but the periapsis passage remains the only candidate there.

 

[n122vu]

Please de-orbit your debris !! (in a controlled fashion) :facts:

LOL

It was actually planned to be retrieved during a shuttle mission, until the Columbia disaster.

Can't remember if anyone posted this yet in the thread...
http://www.usatoday.com/tech/scienc...disaster-ended-satellite-retrieval/50529710/1

 

[orb]

Florida Today - The Flame Trench:

• NASA: Falling Satellite Still A Hazard To U.S.
• FAA Warns Pilots About Falling Satellite

SPACE.com: Huge Tumbling Satellite Could Fall to Earth Over US Tonight or Saturday, NASA Says

Universe Today: Where will the UARS Satellite Crash?

Discovery News: Satellite to Crash to Earth Today

CBS News Space: NASA's UARS satellite falls toward re-entry

 

[Wally]

As of 10:30 a.m. EDT on Sept. 23, 2011, the orbit of UARS was 100 miles by 105 miles (160 km by 170 km). Re-entry is expected late Friday, Sept. 23, or early Saturday, Sept. 24, Eastern Daylight Time. Solar activity is no longer the major factor in the satellite’s rate of descent. The satellite’s orientation or configuration apparently has changed, and that is now slowing its descent. 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. It is still too early to predict the time and location of re-entry with any certainty, but predictions will become more refined in the next 12 to 18 hours.

From NASA's UARS section.

 

[Ghostrider]

Get inside a telephone box. Those things can stop a russian tank!

And they're bigger inside.

 

[orb]

Spaceflight Now: UARS Re-entry Updates

NASA: Solar Activity Can Affect Re-Entry of UARS Satellite

 

[T.Neo]

And they're bigger inside.

No! Those aren't your usual telephone boxes, those are the police boxes.

Which are now apparently an anachronism. :hmm:

 

[Notebook]

http://www.bbc.co.uk/news/science-environment-15034073

UARS satellite return expected later

You wait all day for a falling satellite, and it turns up late!

N.

 

[Scav]

It's coming Tuesday.

 

[iamwearingpants]

No touchy, it's got sharp edges :lol: