NASASpaceFlight.com Forum

General Discussion => Live Event Section - Latest Space Flight News => Topic started by: AncientU on 06/19/2017 11:34 pm

Title: SES’s AMC-9 satellite drifting after anomaly
Post by: AncientU on 06/19/2017 11:34 pm
Quote
SES is moving customers off a 14-year-old geostationary communications satellite that’s drifting in orbit following a “significant anomaly” discovered over the weekend.

“SES has taken immediate action in contacting all customers and is working to transfer services to alternative satellite capacity in order to minimize disruption,” the company said in a June 19 statement.

Quote
The Luxembourg-based global fleet operator first became aware of a problem with AMC-9 the morning of June 17 — a Saturday – and was still assessing the situation two days later. The Thales Alenia Space-built satellite was launched in 2003 on a Russian Proton rocket.

Payer said SES does not know whether the satellite, which provides data and broadcast services over the U.S. and Mexico using C- and Ku-band, can be returned to service. Losing the satellite would cost SES up to 20 million euros ($22.3 million) in revenue this year, SES said.

Quote
AMC-9 was designed to last 15 years, but it is not uncommon for geostationary satellites to surpass that age and continue to generate revenue.

http://spacenews.com/sess-amc-9-satellite-drifting-after-anomaly/
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Steven Pietrobon on 06/21/2017 09:40 am
Spacelfight 101 indicates that an "energetic event" is the cause for the drift.

http://spaceflight101.com/amc-9-satellite-anomaly-orbit-change/

"Orbital tracking data provided by the Joint Space Operations Center showed the AMC 9 satellite in a stable Geostationary Orbit of 35,775 by 35,798 Kilometers, inclined 0.017° as of Saturday, 6:06 UTC. The next tracking data set from Monday, 10:20 UTC shows the satellite in a 35,615 by 35,984-Kilometer, 0.028-degree orbit. – strongly indicating Saturday’s anomaly involved some type of energetic event sufficient to nudge the satellite out of a fully synchronous orbit. Now orbiting an average of 13 Kilometers away from a synchronous orbit, AMC 9 is drifting at approximately 0.16 degrees per day."
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: synchrotron on 06/21/2017 01:28 pm
If Orbital ATK had a Mission Extension Vehicle deployed, we'd get a chance to see AMC-9 brought back to service for awhile or properly graveyarded.  Under the assumption that AMC-9 still has some attitude control authority.

Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Norm38 on 06/22/2017 05:53 pm
What's the orbit?  For a purely circular orbit that isn't synchronous, the bird would be either be above and slower or below and faster.  It's orbit would not intersect other satellites.  But if the orbit is elliptical and out of control, then it could collide with something, correct?

There is a very large need for tenders out there that can go grab and properly dispose of problem sats like this.
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: russianhalo117 on 06/22/2017 06:02 pm
What's the orbit?  For a purely circular orbit that isn't synchronous, the bird would be either be above and slower or below and faster.  It's orbit would not intersect other satellites.  But if the orbit is elliptical and out of control, then it could collide with something, correct?

There is a very large need for tenders out there that can go grab and properly dispose of problem sats like this.
Current TLE:
AMC-9 (GE-12)           
1 27820U 03024A   17172.92543620 -.00000214  00000-0  00000-0 0  9995
2 27820   0.0236 331.7955 0043587  52.0198 136.3406  1.00224706 51479

https://www.celestrak.com/NORAD/elements/ses.txt
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: FutureSpaceTourist on 07/02/2017 02:50 am
Quote
A large satellite appears to be falling apart in geostationary orbit
It is not clear what might have caused the AMC-9 satellite to become unresponsive.

by Eric Berger - Jul 2, 2017 3:41am BST

https://arstechnica.com/science/2017/07/a-large-satellite-appears-to-be-falling-apart-in-geostationary-orbit/ (https://arstechnica.com/science/2017/07/a-large-satellite-appears-to-be-falling-apart-in-geostationary-orbit/)

https://www.youtube.com/watch?v=8ebIAUjFfZM (https://www.youtube.com/watch?v=8ebIAUjFfZM)
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: kevin-rf on 07/02/2017 01:20 pm
Appears to be tumbling. I wonder how fast it can tumble before major items like solar panels and antennas start to break off. Wonder if the bright object is one of the solar panels.
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: FutureSpaceTourist on 07/02/2017 03:24 pm
Quote
SES re-establishes communications with AMC-9; pieces of satellite appear to have broken off
by Peter B. de Selding | Jul 2, 2017

https://www.spaceintelreport.com/ses-re-establishes-communications-amc-9-pieces-satellite-appear-broken-off/ (https://www.spaceintelreport.com/ses-re-establishes-communications-amc-9-pieces-satellite-appear-broken-off/)
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Ben the Space Brit on 07/02/2017 05:10 pm
So, MMOD strike or catastrophic component failure (like an RCS prop tank)?
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: vt_hokie on 07/03/2017 03:25 pm
What's the orbit?  For a purely circular orbit that isn't synchronous, the bird would be either be above and slower or below and faster.  It's orbit would not intersect other satellites.  But if the orbit is elliptical and out of control, then it could collide with something, correct?

There is a very large need for tenders out there that can go grab and properly dispose of problem sats like this.

There are two relatively stable longitudes in geostationary orbit, 75 deg E and 105 deg W, and all other satellites in GEO without stationkeeping will eventually drift as perturbations pull them out of their circular orbit and will oscillate about the nearest stable point I believe.  I've been out of the business a long time, so please correct me if I'm wrong! 
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Thomas Dorman on 07/03/2017 08:54 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. The only thing we can come up with is a parallax effect caused by this video being made from videos shot from  two or more locations.  Must caution those in the media and others in reading to much into to this,like some have already done,that it was some kind of attack from another satellite.
 From inspecting the video frame by frame and zooming in and using inverted video versions ,in addition to speeding up the video 2.5 to 3 time the speed of the original video and shuffling the different versions of the video back and forth of the satellite and the break up we see eight pieces of debris from this event with a possible one more. One problem some people are getting confused with is the other unidentified satellites or  possible old debris passing though the video.
 Graphically looking at the flash rates of the satellite as  the video  moved in time to the break up it seems clear the satellite started to spin up or tumble rapidly to the point of the break up. Just observations from the peanut gallery. Have been trying to observe AMC 9 since the problem started just can get out from under the clouds.
Regards
Thomas
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Thomas Dorman on 07/04/2017 04:57 am
Here are link to videos we made from the AMC 9 break up video by ExoAnalyic Solutions. These are not no were near the resolution we are using since most range in size from 9 Gb to more than 26 Gb and we do not have the storage on line to post such size videos. You can view them in the drop box and speed them up to 4 x speed but shuffling the videos is impossible in drop box they are also downloadable. All credit goes to ExoAnalyic Solutions. Any one using them that make money should should get permission from ExoAnalyic Solution to use them. This was done for research,education and for fun.  "Correct to link which now should be working."
https://www.dropbox.com/s/drswve8sx4vp7cn/AMC%209%20break%20up%20video%20d1%20inverted%20zoomed%20cropped.avi?dl=0
 here is the second one
 https://www.dropbox.com/s/6ptghidwchz9in3/AMC%209%20break%20up%20video%20d1cropped%20zoomed.avi?dl=0

Both are zoom in ,cropped the first is an inverted version the second is a black and white version.
If downloaded remember to adjust player screen size, contrast and brightness to best suits your viewing of the videos. We use Quick time and image J to shuffle and speed up the video. They will be some what blurry and pixelated because of the zoom. You decide what is going on! Regards Thomas
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Thomas Dorman on 07/04/2017 05:48 pm
And the non-sense begins! :o ??? ::)
https://youtu.be/NQ6xsqhDTaU

Regards
Thomas
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: jgoldader on 07/05/2017 01:24 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.
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Thomas Dorman on 07/05/2017 01:48 pm
jgoldader
One other issue with the video is the tracking of the satellite,while the imaging was taking place, it has a very apparent wobble or jumping which is coming from the tracking mount. It is not just  this fragment having strange looking motion. There is one of the other brighter fragments that comes off the lower left hand side which moves away from AMC 9 then makes what looks like an almost  90 degree turn and travels to the right just under the brightest fragment and then passes out of the field of the camera to the right side.
 In addition we believe there may and we must stress maybe a cloud like event showing on the video just as the break up event begins. This cloud, if it is not a image or video artifact, is right at the limit of being visible at the 12 to 3 O'clock position.
Regards
Thomas
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: eeergo on 07/17/2017 11:21 am
Update from Peter de Selding: https://twitter.com/pbdes/status/886906498986762240

Quote from: pbdes
SES regained telemetry of the craft on July 1st. AMC-9 continues to drift westward at approximately 0.2 deg/day with an apogee approximately 190 km above GEO, perigee 155 km below GEO, and a daily longitude variation of 1 degree in a stable and predictable orbit. We continue to monitor the orbit and attitude rates to identify conjunctions and facilitate further attitude and maneuver analysis as SES works with assistance from Thales on possible re-orbiting options for AMC-9.
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Star One on 07/17/2017 11:33 am
Update from Peter de Selding: https://twitter.com/pbdes/status/886906498986762240

Quote from: pbdes
SES regained telemetry of the craft on July 1st. AMC-9 continues to drift westward at approximately 0.2 deg/day with an apogee approximately 190 km above GEO, perigee 155 km below GEO, and a daily longitude variation of 1 degree in a stable and predictable orbit. We continue to monitor the orbit and attitude rates to identify conjunctions and facilitate further attitude and maneuver analysis as SES works with assistance from Thales on possible re-orbiting options for AMC-9.

It's an old satellite wouldn't it be better that if possible they just put it into a standard retirement orbital position?
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Ben the Space Brit on 07/17/2017 12:27 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).
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: russianhalo117 on 07/17/2017 02:04 pm
Update from Peter de Selding: https://twitter.com/pbdes/status/886906498986762240

Quote from: pbdes
SES regained telemetry of the craft on July 1st. AMC-9 continues to drift westward at approximately 0.2 deg/day with an apogee approximately 190 km above GEO, perigee 155 km below GEO, and a daily longitude variation of 1 degree in a stable and predictable orbit. We continue to monitor the orbit and attitude rates to identify conjunctions and facilitate further attitude and maneuver analysis as SES works with assistance from Thales on possible re-orbiting options for AMC-9.

It's an old satellite wouldn't it be better that if possible they just put it into a standard retirement orbital position?
That is what it is sounds like they are referring to.
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Star One on 07/17/2017 07:09 pm
Update from Peter de Selding: https://twitter.com/pbdes/status/886906498986762240

Quote from: pbdes
SES regained telemetry of the craft on July 1st. AMC-9 continues to drift westward at approximately 0.2 deg/day with an apogee approximately 190 km above GEO, perigee 155 km below GEO, and a daily longitude variation of 1 degree in a stable and predictable orbit. We continue to monitor the orbit and attitude rates to identify conjunctions and facilitate further attitude and maneuver analysis as SES works with assistance from Thales on possible re-orbiting options for AMC-9.

It's an old satellite wouldn't it be better that if possible they just put it into a standard retirement orbital position?
That is what it is sounds like they are referring to.

I did wonder but for myself that wasn't clear from the released statement.
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: vt_hokie 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. 
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Star One 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 satellite’s vicinity broke off from the spacecraft or originated elsewhere.

http://spacenews.com/ses-trying-to-retire-amc-9-uncertain-on-debris-origin/
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Thomas Dorman 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
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: FutureSpaceTourist 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
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Ben the Space Brit 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".
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: savuporo 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 don’t know. There are lots of theories, including that it could be elements of propulsion — 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 that’s 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 it’s 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 — 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.
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: kevin-rf 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.
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Comga 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 (https://en.wikipedia.org/wiki/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.)
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: FutureSpaceTourist 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
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Ben the Space Brit 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.
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Thomas Dorman 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
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Thomas Dorman 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!
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: jgoldader 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.
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: synchrotron 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.
Title: SES’s AMC-9 satellite drifting after anomaly
Post by: Star One on 09/26/2017 02:49 pm
It is now giving bright flashes.

http://www.satobs.org/seesat/Sep-2017/0124.html

Here is the relevant new video from Kevin Fetter.

https://www.youtube.com/watch?v=EnoMKsvq8J0
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Ben the Space Brit on 09/27/2017 12:42 pm
So, the flash means that there the spacecraft is rotating? Could that be an outcome of Thales' reported upcoming attempt to use the thrusters to push the vehicle into a safer orbit?
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: kevin-rf on 09/27/2017 01:10 pm
Rotating or tumbling, as rotating about more than one axis at different rates?
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Thomas Dorman on 09/27/2017 10:46 pm
The reason for the very bright flash from AMC 9 on Kevin Fetter's video, at this time, has to do with what happens visually with Geosats around the spring and fall equinox where GeoSats give off very bright flashes which some can easily be seen with the naked eye.  It has nothing to do with anyone doing anything with AMC9. As far as we know there have been zero reports that they have regained any control over  AMC 9. Observed AMC 9 visually around a month or so ago and it was flashing then and has been flashing since the failure event took place!
Just for the recorded Kevin Fetter is one of the world best amateur Satellite videographers who use relatively low-cost equipment and has been the first to capture, on video, several important satellites, no long after launch and events over the years.
Very nice video capture Kevin of the flash from AMC 9!
Regards
Thomas
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Sam Ho on 09/27/2017 10:57 pm
Rotating or tumbling, as rotating about more than one axis at different rates?

Thales said, in an interview mentioned up-thread, that "the attitude control, while stable, is not optimal" and "the satellite is turning on itself."  It appears that they are timing commanding and thruster firing based on when AMC-9 is in the appropriate attitude; Thales expects to get AMC-9 into a graveyard orbit in "several weeks."

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
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Thomas Dorman on 09/27/2017 11:39 pm
First, the report linked is more the opinion of the reporter. The statement from SES  should be taken with a grain of salt and is more like a statement of damage control with shareholders. There clearly was a break-up having taken this video apart and studied it closely. Nope, it was not a total break-up AMC 9! SES are playing a word game which we believe is for damage control with its shareholders. AMC 9 is still drifting west down the GeoSat belt and the only change we can see is the loop-de-loop it has been making has become a little more elongated over time. Maybe SES would feel better if it was called a fragmentation of AMC 9! ;)
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: kevin-rf on 09/28/2017 01:42 am
The reason for the very bright flash from AMC 9 on Kevin Fetter's video, at this time, has to do with what happens visually with Geosats around the spring and fall equinox where GeoSats give off very bright flashes which some can easily be seen with the naked eye.

I think the key difference here is Geo satellites with positive attitude control during equinox season solar panels will flare as the satellite approaches for lack a better word, the back side of the earth  moving between the satellite and the sun.
That said, if AMC 9 is spinning, you would expect a repeating pattern with a period. He did not report that. Which means that they have either regained attitude control (which they have not reported) or it is tumbling (rotating around several axis's) and randomly pointing the panels in different directions, including that one lucky flare orientation.

I vote tumbling.
Title: Re: SES’s AMC-9 satellite drifting after anomaly
Post by: Thomas Dorman on 09/28/2017 04:03 pm
 kevin-rf
We vote tumbling too! Then for SES irregular multi-axises rotation or IMAR for short, ::) seems to be a better fit for their damage control model with shareholder and investors! Next time we get a clear night will see if we can get some video of the flashes to see how irregular they are!
Regards
Thomas