Author Topic: SESís AMC-9 satellite drifting after anomaly  (Read 8481 times)

Offline vt_hokie

  • Senior Member
  • *****
  • Posts: 3010
  • Williamsburg, VA
  • Liked: 86
  • Likes Given: 176
Re: SESís AMC-9 satellite drifting after anomaly
« Reply #20 on: 07/24/2017 03:59 PM »
The question is whether the spacecraft still retains orbital adjustment authority. If the causative anomaly was a fault in the propellent system of either the RCS or MPS then the satellite may not be controllable beyond attitude control (if it has reaction wheels).

Even reaction wheels require thrusters or magnetic torquers to unload momentum and prevent the wheels from saturating.  But I think that's a moot point for this satellite, sadly. 

Offline Star One

  • Senior Member
  • *****
  • Posts: 7779
  • UK
  • Liked: 1238
  • Likes Given: 168
Re: SESís AMC-9 satellite drifting after anomaly
« Reply #21 on: 08/07/2017 05:49 PM »
SES trying to retire AMC-9, uncertain on debris origin

Quote
Satellite fleet operator SES says it will retire the malfunctioning AMC-9 satellite a year early if it can regain control of the spacecraft.

Quote
The company has also not been able to confirm if debris spotted in the satelliteís vicinity broke off from the spacecraft or originated elsewhere.

http://spacenews.com/ses-trying-to-retire-amc-9-uncertain-on-debris-origin/

Offline Thomas Dorman

  • Member
  • Posts: 98
  • Tahlequah Oklahoma
  • Liked: 64
  • Likes Given: 5
Re: SESís AMC-9 satellite drifting after anomaly
« Reply #22 on: 08/15/2017 08:49 AM »
Star One
Observed AMC-9  a little over two weeks ago and it was still flashing and Kevin Fetter in Canada has observed it in the last 24 hour and it continues to flash. Any illusion that this satellite will be retired in the conventional sense  is just that an illusion off. AMC 9 is toast and will be a problem in geosat orbit for years to come.
Regards
Thomas

Online FutureSpaceTourist

  • Senior Member
  • *****
  • Posts: 3661
  • UK
    • Plan 28
  • Liked: 2437
  • Likes Given: 800
Re: SESís AMC-9 satellite drifting after anomaly
« Reply #23 on: 09/18/2017 01:59 PM »
Quote
Peter B. de Selding‏ @pbdes 14m14 minutes ago

Manufacturer of @SES_Satellites AMC-9, @Thales_Alenia_S says no sign of breakup despite @exoanalytic radar images.

https://www.spaceintelreport.com/amc-9-satellite-builder-says-theres-absolutely-no-sign-orbit-breakup/

https://twitter.com/pbdes/status/909775092359532544

Offline edkyle99

  • Expert
  • Senior Member
  • *****
  • Posts: 12576
    • Space Launch Report
  • Liked: 3382
  • Likes Given: 561
Re: SESís AMC-9 satellite drifting after anomaly
« Reply #24 on: 09/18/2017 03:29 PM »
Quote
Peter B. de Selding‏ @pbdes 14m14 minutes ago

Manufacturer of @SES_Satellites AMC-9, @Thales_Alenia_S says no sign of breakup despite @exoanalytic radar images.

https://www.spaceintelreport.com/amc-9-satellite-builder-says-theres-absolutely-no-sign-orbit-breakup/

https://twitter.com/pbdes/status/909775092359532544
Those didn't look like "radar images" to me.  They seemed to be optical images, and something(s) clearly separated from the satellite.  If not parts of the satellite itself, then what?  Ice?  Or were the images fake?

 - Ed Kyle

Offline Ben the Space Brit

  • Senior Member
  • *****
  • Posts: 6919
  • A spaceflight fan
  • London, UK
  • Liked: 519
  • Likes Given: 588
Re: SES’s AMC-9 satellite drifting after anomaly
« Reply #25 on: 09/18/2017 03:39 PM »
Every Internet disaster connoisseur knows about Kessler Syndrome and I have no doubt that satellite manufacturers and operators have a standing policy of denial of any hint that a satellite has broken up (especially in an energetic way) to avoid creating investor panic.

This almost certainly includes a policy of 'I didn't see any pictures' when, as in the case of AMC-9, the breakup has actually been recorded.

I'm anticipating the following sequence of disclaimers from Thales:

1. "There is no evidence that AMC-9 has broken up";
2. "Those images have either been altered or the 'debris' traces are photographic flaws";
3. "The image is being misinterpreted by those without technical knowledge";
4. "There is no indication of an energetic break-up";
5. "All debris is being tracked and there is no indication that the energetic break-up with imperil other spacecraft."
6. "All debris is being tracked and all spacecraft that are plausibly at risk are already carrying out debris avoidance manoeuvres";
7. "The chance of debris that cannot be tracked due to size or low albedo actually contacting another active spacecraft are vanishingly small";
8. "There is no legally-admissible evidence that the loss of [$Satellite_Designation] is in any way related to the break-up of AMC-9".
« Last Edit: 09/18/2017 04:23 PM by Ben the Space Brit »
"Oops! I left the silly thing in reverse!" - Duck Dodgers

~*~*~*~

The Space Shuttle Program - 1981-2011

The time for words has passed; The time has come to put up or shut up!
DON'T PROPAGANDISE, FLY!!!

Offline savuporo

  • Senior Member
  • *****
  • Posts: 5051
  • Liked: 909
  • Likes Given: 325
Re: SESís AMC-9 satellite drifting after anomaly
« Reply #26 on: 09/18/2017 03:49 PM »
The gist of it is here

Quote
Radar images show something that appears to be debris alongside AMC-9.

What that is I donít know. There are lots of theories, including that it could be elements of propulsion ó gases that were emitted and then froze, and that now produce a  radar signature resembling satellite debris.

SES, which gets information from space agencies looking at the situation, has also concluded that there is no evidence showing a breakup.

Could it be a thermal blanket that detached? I suppose thatís possible but the information we have indicates a satellite that is whole.

On one hand, he basically says telemetry confirms full structural integrity of the sat. However, right above there he says attitude control ( and possibly main propulsion ) has taken a hit

Quote
Since then, we have reestablished full control. We receive the telemetry, the satellite receives our commands. The satellite is in a stable condition and we are now preparing the de-orbiting procedure.

That takes some time because the the attitude control, while stable, is not optimal. We need to adapt a command sequence to accommodate the fact that the satellite is turning on itself. But itís a predictable sequence and we now know the condition of the satellite.

We are optimizing the sequence to boost the satellite into a retirement orbit. This will take several weeks because we cannot order thruster firings as we would in a satellite that was in normal health.


This one got me: it could be elements of propulsion ó gases that were emitted and then froze, and that now produce a  radar signature resembling satellite debris.. Yeah, these satellite-emitted propulsion elements would be called ... satellite debris.
« Last Edit: 09/18/2017 04:03 PM by savuporo »
Orion - the first and only manned not-too-deep-space craft

Offline kevin-rf

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 8483
  • Overlooking the path Mary's little Lamb took..
  • Liked: 1016
  • Likes Given: 233
Re: SESís AMC-9 satellite drifting after anomaly
« Reply #27 on: 09/18/2017 03:56 PM »
I just read it as tons of legal speak to provide cover to deny everything possible with very little new hard information.
If you're happy and you know it,
It's your med's!

Offline Comga

  • Senior Member
  • *****
  • Posts: 3857
  • Liked: 1205
  • Likes Given: 1032
Re: SESís AMC-9 satellite drifting after anomaly
« Reply #28 on: 09/18/2017 09:20 PM »
Can some one explain the motion in the video of the largest bright fragment from AMC 9 AKA GE 12. Having now taken the video apart and looked closely  this fragment is at first moving away from AMC 9 then makes what looks like a near 180 degree turn and moves back towards AMC 9.
Thomas

The video was tracking the satellite itself.  The motion of the fragment(s) is then relative to the main body of the satellite.  If some propulsive event moved the main body of the satellite in the direction of the largest fragment, it would give the appearance of the fragment moving back towards the satellite.  This is only one possible explanation, of course; I suppose the fragment itself might've experienced an impulse somehow.  It should be fairly easy for somebody with access to the raw data to tell if the satellite's motion changed during the observation.  I bet you could take a few frames on either side of the apparent change in motion of the fragment and check the motion of the main piece and fragment relative to the background stars before and after the event, see which one changed.

Remember, this is in a rotating coordinate system.  As we know, it only looks like it's standing still.

In the rotating coordinate system of orbit, an object that is released from another will follow curved relative paths.  If the release is at right angle from the initial objects velocity, the orbital period won't be changed and the released object will arc back to the main body after one revolution, here one day.  Because the period will in practice be modified by some number of seconds the released object will wind up in a slightly longer or shorter orbit, and walk either backwards or forwards with respect to the main body.  Every time it circles back, at the end of N days, it will be a little farther from the main body.

This all happens without subsequent impulse events.  You can read about the Clohessy-Wiltshire equations online and in textbooks.

The multiple object passing by looks like a typical grouping in geosynchronous orbit. It appears, in this video, that AMC-9 is drifting back along the geosynchronous belt, and ran into a satellite keeping station.

Gosh that voiceover is SUPER annoying.  Gibberish.  Goofy stuff.  Just because he doesn't understand does not mean the most logical explanations are aliens or an active shooting war in geosynchronous orbit.  "Never attribute to malice what is adequately explained by stupidity."  (I am referring to the satellite breakup but it could refer to the guy speaking.)
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Online FutureSpaceTourist

  • Senior Member
  • *****
  • Posts: 3661
  • UK
    • Plan 28
  • Liked: 2437
  • Likes Given: 800
Re: SESís AMC-9 satellite drifting after anomaly
« Reply #29 on: 09/19/2017 08:08 AM »
Quote
Peter B. de Selding‏ @pbdes 14m14 minutes ago

Manufacturer of @SES_Satellites AMC-9, @Thales_Alenia_S says no sign of breakup despite @exoanalytic radar images.

https://www.spaceintelreport.com/amc-9-satellite-builder-says-theres-absolutely-no-sign-orbit-breakup/

https://twitter.com/pbdes/status/909775092359532544

Just tweeted:

Quote
Update: @exoanalytic responding to @Thales_Alenia_S, stands by its original report, will update at @amoscon this wk.

https://twitter.com/pbdes/status/910048377102045184

Offline Ben the Space Brit

  • Senior Member
  • *****
  • Posts: 6919
  • A spaceflight fan
  • London, UK
  • Liked: 519
  • Likes Given: 588
Re: SESís AMC-9 satellite drifting after anomaly
« Reply #30 on: 09/19/2017 12:12 PM »
I'm glad that Exoanalytic are not letting even a big player like Thales get away with essentially calling them either liars or fools.
"Oops! I left the silly thing in reverse!" - Duck Dodgers

~*~*~*~

The Space Shuttle Program - 1981-2011

The time for words has passed; The time has come to put up or shut up!
DON'T PROPAGANDISE, FLY!!!

Offline Thomas Dorman

  • Member
  • Posts: 98
  • Tahlequah Oklahoma
  • Liked: 64
  • Likes Given: 5
Re: SESís AMC-9 satellite drifting after anomaly
« Reply #31 on: 09/19/2017 03:13 PM »
See this across the internet claiming the Exoanlytic' video was made by radar. Can anyone explain!
Regards
Thomas

Offline Thomas Dorman

  • Member
  • Posts: 98
  • Tahlequah Oklahoma
  • Liked: 64
  • Likes Given: 5
Re: SESís AMC-9 satellite drifting after anomaly
« Reply #32 on: 09/19/2017 03:17 PM »
The ExoAnalytic Global Telescope Network consists of over 150 ground-based telescopes located in North America, South America, Australia, Africa, Europe, and Hawaii.
Clearly not radar imagery!
« Last Edit: 09/19/2017 03:18 PM by Thomas Dorman »

Offline jgoldader

  • Full Member
  • ****
  • Posts: 658
  • Liked: 220
  • Likes Given: 128
Re: SESís AMC-9 satellite drifting after anomaly
« Reply #33 on: 09/19/2017 11:00 PM »
I can't see how the video linked to by FutureSpaceTourist on page 1 on this thread could be from radar.  You would not see star trails in a radar image, just for starters.  On the other hand, it has every appearance of being from an optical camera attached to a telescope.

Maybe there were radar detections of some sort, but they'd be independent of the video.

Also, Comga's explanation of the apparent reversed motion potentially** being simply due to different orbital elements is quite possible, and probably more likely than mine: Occam's razor.

**Modified for clarification: If the orbital elements (in particular eccentricity) are different, then I can see how you'd get back-and-forth motion of one object relative to the other.  The "if" is the potentially part.  Again, I believe Comga's got it right.
« Last Edit: 09/20/2017 09:33 PM by jgoldader »
Recovering astronomer

Offline synchrotron

  • Member
  • Full Member
  • **
  • Posts: 296
  • Liked: 5
  • Likes Given: 10
Re: SESís AMC-9 satellite drifting after anomaly
« Reply #34 on: 09/20/2017 03:10 PM »
Also, Comga's explanation of the apparent reversed motion potentially being simply due to different orbital elements is quite possible, and probably more likely than mine: Occam's razor.

It's not 'potentially being simply due to' different eccentricities, it's actually due to it. It's basic orbital mechanics.

Tags: