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General Astronomy >> General Observing and Astronomy

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obin robinson
Carpal Tunnel
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Reged: 10/25/12

Loc: League City, TX
Heads up! GOCE is decaying and will re-enter soon
      #6175697 - 11/04/13 03:09 PM

The ESA's GOCE satellite has ended its multi-year mission and is rapidly decaying. GOCE has been on a gravity mapping mission for years. The mission came to an end a few weeks ago and the satellite will re-enter the atmosphere soon.

http://www.esa.int/Our_Activities/Observing_the_Earth/GOCE/GOCE_completes_its...

Updates can be tracked from here.

http://www.n2yo.com/?s=34602

This should be interesting.

obin


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sg6
professor emeritus


Reged: 02/14/10

Loc: Norfolk, UK.
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: obin robinson]
      #6177547 - 11/05/13 02:30 PM

Looked at the tracling site and the altitude has steadily increased from 206.7 to 211.8Km.

Isn't it supposed to be comng down?


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obin robinson
Carpal Tunnel
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Reged: 10/25/12

Loc: League City, TX
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: sg6]
      #6177639 - 11/05/13 03:30 PM

It is in an elliptical orbit. It's 193km and descending as of this minute and dropping. In septermber it was 230+km in altitude.

http://www.spaceflight101.com/goce-re-entry.html

It's coming down and we don't know where exactly. Hopefully it will be over the ocean.

obin


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panhardModerator
It's All Good
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Reged: 01/20/08

Loc: Markham Ontario Canada
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: obin robinson]
      #6177961 - 11/05/13 06:32 PM

Heads up???? Duck incoming. Thanks for the warning. Let's hope it has a wet landing.

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obin robinson
Carpal Tunnel
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Reged: 10/25/12

Loc: League City, TX
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: panhard]
      #6178000 - 11/05/13 06:51 PM

It's dipping down to 190km! It's going to be an interesting re-entry!

obin


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obin robinson
Carpal Tunnel
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Reged: 10/25/12

Loc: League City, TX
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: obin robinson]
      #6179403 - 11/06/13 02:38 PM

The orbit has shrank down to 183 x 191 kilometers. Current estimate for re-entry is Monday, November 11, 2013, +/-1 day. If it starts tumbling it may re-enter earlier. I think it will dip pretty low before it stars tumbling because it is a very streamlined design. As it dips lower you should be able to see it clearly at high magnification. Once it starts tumbling it will put on quite a display. The satellite body has plenty of reflective surfaces at angles which will make it flash like a strobe in the sky as it tumbles.

obin


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ischua
Under the Radar
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Reged: 07/17/08

Loc: Below Snow Plop, N Y
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: obin robinson]
      #6183695 - 11/08/13 09:27 PM

ALTITUDE [mi]: 105 dropped 10mi in the last 20 min and back up to 119 in the same amount of time.

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WarmWeatherGuy
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Reged: 08/27/11

Loc: Orlando, FL 28° N, 81° W
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: obin robinson]
      #6184534 - 11/09/13 11:39 AM

The story has made it to Newsy

http://www.newser.com/story/177305/european-satellite-falling-back-to-earth.html


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NoRain
journeyman


Reged: 07/16/13

Re: Heads up! GOCE is decaying and will re-enter soon new [Re: obin robinson]
      #6184565 - 11/09/13 11:56 AM

Hello
http://www.n2yo.com/space-station/
Its also tracks things that are not going to fall on us just yet.


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obin robinson
Carpal Tunnel
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Reged: 10/25/12

Loc: League City, TX
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: NoRain]
      #6185254 - 11/09/13 06:55 PM

It's dipping under 160km/100 miles. This thing is literally in the upper atmosphere at the altitude that meteors start to burn. It can't be long now. I'd keep eyeballs pointed at the sky if I were in the flight path. GOCE should be spectacular as it burns up.

obin


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T1R2
Carpal Tunnel


Reged: 06/11/13

Loc: NeverWhere, 35*N
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: obin robinson]
      #6185298 - 11/09/13 07:25 PM

has just dipped to the 98 mi.alt. mark and went off radar over E China, I don't know if this means it had just re-entered, or a glich in my comp. but interesting.

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T1R2
Carpal Tunnel


Reged: 06/11/13

Loc: NeverWhere, 35*N
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: T1R2]
      #6185303 - 11/09/13 07:29 PM

just went back to website and it looks to still be up...so, we wait some more.

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WarmWeatherGuy
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Reged: 08/27/11

Loc: Orlando, FL 28° N, 81° W
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: T1R2]
      #6185325 - 11/09/13 07:41 PM

I suspect the altitude given is above an oblate spheroid model of the Earth. For that reason I have been looking at the altitude when it crosses the equator.

Here are the altitudes in miles above the equator while going North to South (descending node) for November 9th. Times are EST, p.m.

12:10 99.47
1:38 99.??
3:06 98.39
4:34 97.85
6:02 97.15
7:30 96.30
8:56 95.46
10:24 94.63
11:52 93.81

Here are the altitudes in miles above the equator while going South to North (ascending node)

12:54 101.90
2:22 101.48
3:50 100.99
5:18 100.55
6:46 98.70
8:12 98.00
9:40 97.29
11:08 96.59

Notice the big drop in apogee (or close to apogee?) at 6:46.

The website shows you where it thinks the satellite is, not where it actually is. It probably gets periodic updates so a big jump may be due to an update.

Edit: added more data points

Edited by WarmWeatherGuy (11/10/13 12:19 AM)


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obin robinson
Carpal Tunnel
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Reged: 10/25/12

Loc: League City, TX
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: WarmWeatherGuy]
      #6185498 - 11/09/13 09:38 PM

http://www.spaceflight101.com/goce-re-entry.html

" According to ESA, GOCE is still operating with average drag levels now above 90 Millinewtons. Gradiometer data is only usable when drag levels are less than 80mN. The satellite is still maintaining its attitude and will likely remain in an aerodynamically stable position until re-entry and disintegration.

"Recently we have noticed a significant temperature increase in several areas of the spacecraft, arguably linked to GOCE encountering a more and more dense atmosphere as its orbit keeps dropping," GOCE Operations Manager Christoph Steiger said in a status update.

Re-Entry is still expected to occur in the overnight hours on Sunday/Monday."

Re-Entry Predictions:
ESA: Night of November 10-11
USSTRATCOM: November 10, 2013 - 23:02 UTC +/-16 Hours
Aerospace Corp.: November 11, 2013 - 8:20 UTC +/-15 Hours

Plus or minus 15 or 16 hours? You gotta love that "accuracy" being computed by multi million dollar computers. LOL.

obin


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Megabusa
professor emeritus


Reged: 05/28/12

Loc: Page ,AZ
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: obin robinson]
      #6185640 - 11/09/13 11:27 PM

So how or we doing this ? I'm looking at the tracking and all we can do is hope it starts interring the atmosphere where we can see it in our area, right ? are it could be over China or something and we miss it , ( Re-Entry is still expected to occur in the overnight hours on Sunday/Monday ) So as I'm looking at the tracking, is there a way to find that it's starting to re-enter ? Or do we just look up at the general vicinity when it's passing over ?

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T1R2
Carpal Tunnel


Reged: 06/11/13

Loc: NeverWhere, 35*N
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: Megabusa]
      #6185651 - 11/09/13 11:33 PM

that's about all we can do for now Mega, I've not seen it yet,

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Megabusa
professor emeritus


Reged: 05/28/12

Loc: Page ,AZ
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: T1R2]
      #6185661 - 11/09/13 11:40 PM

Quote:

that's about all we can do for now Mega, I've not seen it yet,


I got my eyes glued to that tracking site ,

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T1R2
Carpal Tunnel


Reged: 06/11/13

Loc: NeverWhere, 35*N
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: Megabusa]
      #6185687 - 11/09/13 11:59 PM

every time I've checked, its been over China or Alaska or the ocean.

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WarmWeatherGuy
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Loc: Orlando, FL 28° N, 81° W
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: Megabusa]
      #6185706 - 11/10/13 12:14 AM

Quote:

So how or we doing this ? I'm looking at the tracking and all we can do is hope it starts interring the atmosphere where we can see it in our area, right ? are it could be over China or something and we miss it , ( Re-Entry is still expected to occur in the overnight hours on Sunday/Monday ) So as I'm looking at the tracking, is there a way to find that it's starting to re-enter ? Or do we just look up at the general vicinity when it's passing over ?




The tracking is a calculation based on old data. We don't have radar on it continuously. The satellite will reenter the atmosphere and the web site will show it still going round and round. We will have to read about it in the news after the fact.

The orbit is near the terminator so if you're going to see it come crashing down it will have to be in the morning or the evening for you. You won't see it happen at midnight or noon. Where ever it happens it will be where the Sun is low to the horizon, or just below the horizon.


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Megabusa
professor emeritus


Reged: 05/28/12

Loc: Page ,AZ
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: WarmWeatherGuy]
      #6185738 - 11/10/13 12:41 AM

Quote:

Quote:

So how or we doing this ? I'm looking at the tracking and all we can do is hope it starts interring the atmosphere where we can see it in our area, right ? are it could be over China or something and we miss it , ( Re-Entry is still expected to occur in the overnight hours on Sunday/Monday ) So as I'm looking at the tracking, is there a way to find that it's starting to re-enter ? Or do we just look up at the general vicinity when it's passing over ?




The tracking is a calculation based on old data. We don't have radar on it continuously. The satellite will reenter the atmosphere and the web site will show it still going round and round. We will have to read about it in the news after the fact.

The orbit is near the terminator so if you're going to see it come crashing down it will have to be in the morning or the evening for you. You won't see it happen at midnight or noon. Where ever it happens it will be where the Sun is low to the horizon, or just below the horizon.


Thank U for the Heads Up

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obin robinson
Carpal Tunnel
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Reged: 10/25/12

Loc: League City, TX
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: Megabusa]
      #6186398 - 11/10/13 11:37 AM

http://www.spaceflight101.com/goce-re-entry.html

"[15:30 UTC]: GOCE is now at 133 Kilometers dropping about 1.5km per hour and re-entry is less than 10 hours away. The satellite is still operating. Drag levels are preventing any more Gradiometer science so the instrument was switched off. GOCE is in a stable attitude, continuing to make good measurements with its GPS receivers. ESA plans to operate the satellite as long as possible, keeping up regular ground station passes to downlink data."

It looks like it will re-enter before the end of the day.

obin


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choran
Carpal Tunnel
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Reged: 12/28/12

Re: Heads up! GOCE is decaying and will re-enter soon new [Re: obin robinson]
      #6186764 - 11/10/13 02:46 PM

I've got a crack at it. It's due for a visible pass in my area (southern California) at roughly 7:30 tonight. Problem is, it's a low pass, only about 13 degrees above the horizon in any event, out a couple of hundred miles in the Pacific. The time frame is good, though, according to an update on the crash time. I've maybe a chance in 1000, but that's OK. I do have a sure thing in the morning though--ISS at -3.3 at about 5:15 AM.

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obin robinson
Carpal Tunnel
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Reged: 10/25/12

Loc: League City, TX
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: choran]
      #6186903 - 11/10/13 03:47 PM

It's at 133km now. I can't believe it's still in orbit! Get a camera ready just in case it's a bit toasty when it passes you. That might be the last pass!

obin


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rnc39560
Pooh-Bah
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Reged: 07/23/13

Loc: MS coast
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: obin robinson]
      #6187167 - 11/10/13 05:25 PM

Hey Obin, I couldn't see anything from my location huh?

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obin robinson
Carpal Tunnel
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Reged: 10/25/12

Loc: League City, TX
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: rnc39560]
      #6187258 - 11/10/13 06:13 PM

I think we're out of luck in the central part of the country unless it burns up during daylight. it still has a few orbits left.

obin


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Billytk
Pooh-Bah


Reged: 04/22/12

Loc: Lake Mary, Fl.
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: obin robinson]
      #6187621 - 11/10/13 09:48 PM

So, if you were to see it burn up, would you be able to tell it from a meteor?

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rnc39560
Pooh-Bah
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Reged: 07/23/13

Loc: MS coast
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: Billytk]
      #6187782 - 11/10/13 11:27 PM

Its gone. Done. Ka-put

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brianb11213
Postmaster
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Reged: 02/25/09

Loc: 55.215N 6.554W
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: Billytk]
      #6187970 - 11/11/13 03:43 AM

Quote:

So, if you were to see it burn up, would you be able to tell it from a meteor?



I think not - the only thing you might notice is that a re-entering satellite (travelling at "only" 7 kilometers per second) might appear to move more slowly across the sky than a bolide/fireball resulting from infalling solar system debris (travelling at 11 kilometers per second, at least, possibly much, much faster depending on the orbital geometry).

Anyhow, GOCE is now GONE.


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rnc39560
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Reged: 07/23/13

Loc: MS coast
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: brianb11213]
      #6187988 - 11/11/13 04:09 AM

I'm sure we'll have some more debris to track to its demise!

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David Knisely
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Reged: 04/19/04

Loc: southeastern Nebraska
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: rnc39560]
      #6188000 - 11/11/13 04:37 AM

It came down early this evening (0000 UT on Monday, November 11th).

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obin robinson
Carpal Tunnel
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Reged: 10/25/12

Loc: League City, TX
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: brianb11213]
      #6188215 - 11/11/13 09:33 AM

Quote:

Quote:

So, if you were to see it burn up, would you be able to tell it from a meteor?



I think not - the only thing you might notice is that a re-entering satellite (travelling at "only" 7 kilometers per second) might appear to move more slowly across the sky than a bolide/fireball resulting from infalling solar system debris (travelling at 11 kilometers per second, at least, possibly much, much faster depending on the orbital geometry).

Anyhow, GOCE is now GONE.




When something as large as GOCE breaks up it tumbles into thousands of pieces. A meteorite is one object that breaks and burns up quickly. A satellite may have tens of thousands of pieces which are being shed off as it tumbles into the upper atomosphere.

Here's a video of a re-entry:

http://www.youtube.com/watch?v=5AG5T9uzgMY

You can see pieces breaking off as the machine is disintegrating in the atmosphere. GOCE was a sleek and fast moving satellite which was stable until only a few moments before re-entry.

Large objects like Skylab and Mir took a while to disintegrate. Not all of the pieces burned up and several hit the earth.

http://www.youtube.com/watch?v=fVQd9Ejkbiw

obin


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YosoY
journeyman


Reged: 11/10/13

Loc: other side of the sky
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: obin robinson]
      #6188216 - 11/11/13 09:33 AM Attachment (13 downloads)

This is my first post. Wanted to share this pic of a smoke trail over S FL last night. Approx. 50 deg from horizon, looking south to east. Taken at 6:16PM Eastern. After checking several websites, think it might be a chunk of GOCE. Trail has an abrupt start and stop point. Definitely not a plane, this is not a flight path. Bright spot is the moon.

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obin robinson
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Reged: 10/25/12

Loc: League City, TX
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: YosoY]
      #6188220 - 11/11/13 09:35 AM

WOW! If that is GOCE then you have a heck of a first post! Welcome aboard!

obin


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YosoY
journeyman


Reged: 11/10/13

Loc: other side of the sky
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: YosoY]
      #6188227 - 11/11/13 09:40 AM Attachment (12 downloads)

second pic of smoke trail, end point is at Cassiopeia.

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YosoY
journeyman


Reged: 11/10/13

Loc: other side of the sky
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: obin robinson]
      #6188249 - 11/11/13 09:53 AM

Thanks Obin. Been lurking in these forums for a while, glad to contribute something

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choran
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Reged: 12/28/12

Re: Heads up! GOCE is decaying and will re-enter soon new [Re: YosoY]
      #6188282 - 11/11/13 10:15 AM

Wow, that might be it indeed! The time is about right. I haven't read the reports yet on whether it reentered in your location. Should be some verification indeed. I hope you got it! I was hoping somebody would!

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rnc39560
Pooh-Bah
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Reged: 07/23/13

Loc: MS coast
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: choran]
      #6188349 - 11/11/13 10:55 AM

Very cool! Welcome to CN!

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YosoY
journeyman


Reged: 11/10/13

Loc: other side of the sky
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: choran]
      #6188356 - 11/11/13 10:57 AM Attachment (10 downloads)

Maybe not the final entry, but perhaps one of the last orbits since the predictions show it razing the coast of S FL....

Pic from
http://www.slate.com/blogs/bad_astronomy/2013/11/10/goce_european_satellite_a...


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WesC
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Reged: 02/06/13

Loc: La Crescenta, CA
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: YosoY]
      #6188597 - 11/11/13 01:05 PM

I hate to be the party pooper, but I seriously doubt those photos are of GOCE. According to this site GOCE de-orbited very far south, almost at Antarctica, and it was seen breaking up near the Falkland Islands.

http://www.spaceflight101.com/goce-re-entry.html


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brianb11213
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Reged: 02/25/09

Loc: 55.215N 6.554W
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: WesC]
      #6188701 - 11/11/13 01:55 PM

Quote:

I hate to be the party pooper, but I seriously doubt those photos are of GOCE.



Yes. The images look a lot like regular aircraft condensation trails to me.


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YosoY
journeyman


Reged: 11/10/13

Loc: other side of the sky
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: brianb11213]
      #6189161 - 11/11/13 06:12 PM



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rnc39560
Pooh-Bah
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Reged: 07/23/13

Loc: MS coast
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: YosoY]
      #6189200 - 11/11/13 06:37 PM

Hey! Don't be down about it! We like playing sleuth on here! The pic is cool anyway!

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WarmWeatherGuy
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Reged: 08/27/11

Loc: Orlando, FL 28° N, 81° W
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: rnc39560]
      #6189312 - 11/11/13 07:47 PM

It is possible that a piece skipped across the atmosphere like rocks on a pond and came crashing down much further along in the orbit.

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rnc39560
Pooh-Bah
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Reged: 07/23/13

Loc: MS coast
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: WarmWeatherGuy]
      #6189317 - 11/11/13 07:51 PM

Quite possible actually. It was probably shredded to bits like numerous other man-made objects on reentry.

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WesC
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Reged: 02/06/13

Loc: La Crescenta, CA
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: rnc39560]
      #6189376 - 11/11/13 08:21 PM

Not likely, the separation distance between where the break up was sighted and the poster's location is over five thousand miles. Its much more likely that this is just a contrail.

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rnc39560
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Reged: 07/23/13

Loc: MS coast
Re: Heads up! GOCE is decaying and will re-enter soon new [Re: WesC]
      #6189391 - 11/11/13 08:30 PM

Oops..... 5000 miles is a long way to skip a rock on a pond! Lol

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WesC
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Re: Heads up! GOCE is decaying and will re-enter soon new [Re: rnc39560]
      #6189416 - 11/11/13 08:37 PM

Ha! That would be a hell of a shot!

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WarmWeatherGuy
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Re: Heads up! GOCE is decaying and will re-enter soon new [Re: WesC]
      #6189419 - 11/11/13 08:39 PM

When I was in college many years ago I was involved in a group project where we had to design a reentry vehicle for a single astronaut. I was assigned the problem of reducing the number of g's the astronaut took. Our capsule was basically a mini version of the Mercury space capsule but the astronauts took well over 10 g's with that capsule. The Gemini capsules gave their astronauts only around 4 g's max. The way they did it was to offset the CG to one side so the ablative disk would not be perpendicular to the oncoming air but would instead have some tilt. This would provide lift which kept the capsule from reentering all at once. It would spread the deceleration out over many more miles. I wrote a computer simulation and while I was playing with it I found it was possible to have the capsule bounce off the atmosphere. It would start to reenter but then go back up high above the air. Of course it would have lost much speed and eventually come back down even harder the next time. I don't remember exactly how far it went but 5,000 miles was possible. The problem with comparing that to a piece of space debris is that the capsule was aerodynamically stable and the lift was always up. Broken satellite parts will probably tumble and the lift vector would sometimes be down.

The most likely explanation is that a jet plane made the streaks but I wouldn't rule out GOCE parts only because 5,000 miles is too far.


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WesC
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Re: Heads up! GOCE is decaying and will re-enter soon new [Re: WarmWeatherGuy]
      #6189468 - 11/11/13 09:02 PM

That's really interesting! You know I was at the California Science Center last Friday to visit the shuttle Endeavor and while I was there I took a look at the 3 space capsules they have as well (Mercury, Gemini and Apollo). I was noticing how the blast pattern on the Gemini heat shield was off-center and I was curious what that was about... now I know!

Thanks for the informative explanation!


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choran
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Re: Heads up! GOCE is decaying and will re-enter soon new [Re: WesC]
      #6189472 - 11/11/13 09:06 PM

I remember reading somewhere that with satellites, certain parts might fall off sooner than others, like solar panels and such. I've been looking today in the news trying to see whether the breakup/burn took place over a protracted period, or was fast. No luck on my research, though.

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WesC
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Re: Heads up! GOCE is decaying and will re-enter soon new [Re: choran]
      #6189473 - 11/11/13 09:07 PM

From what I have read, due to the aerodynamics of the satellite, it remained remarkable stable until terminal reentry. I suspect that contributed to its break up as well.

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Re: Heads up! GOCE is decaying and will re-enter soon new [Re: WesC]
      #6189972 - 11/12/13 04:12 AM

GOCE re-entry imaged (and filmed) from the Falkland Islands / Malvinas

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YosoY
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Re: Heads up! GOCE is decaying and will re-enter soon new [Re: rnc39560]
      #6191297 - 11/12/13 06:17 PM

Robert,no worries. I was just curious about the pic since the timing, path etc were coincidental with GOCE. Plus, I have never seen a plane on that path. Thanks to all who contributed comments.

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WesC
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Re: Heads up! GOCE is decaying and will re-enter soon new [Re: YosoY]
      #6191446 - 11/12/13 07:40 PM

Hey, don't feel bad about it. We all want to find out what's what, and sometimes you get lucky and are in the right place at the right time.

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Re: Heads up! GOCE is decaying and will re-enter soon new [Re: WesC]
      #6192113 - 11/13/13 07:16 AM

From Gizmodo:


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rnc39560
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Re: Heads up! GOCE is decaying and will re-enter soon new [Re: timtrice]
      #6194709 - 11/14/13 02:25 PM

Cool! Nice pic. Thanks for sharing.

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