G15 troubles

[B.J.]

Very;

Objects at the western liberation point (105W)

CLASSIFICATION OF GEOSYNCHRONOUS OBJECTS -- ISSUE 11_

Well, after an afternoon of manual searching, having searched all the common names of TVRO sats except Galaxy, (which I forgot), I was just about to post that I found 3, Satcom C5, GSTAR 1, and GSTAR 3. I think your list is a wee bit more complete. THANKS.

With just 3 there, I still had my doubts, thinking maybe those were still under control, but with all those there, it does seem like a crowded spot.

The one thing I DID notice, however, which is interesting, and that is these all have approximately the same orbital radius as the regular geosync sats. I guess it makes sense that if this is a stable orbital spot that they should be geosynchronous, and not kicked up into a higher orbit, which is what we normall hear has been done to sats about to die. Most of the old dead sats that are circling the earth are in a higher orbit, either because they have been kicked up there, or due to normal decay. It seems like this 105W slot is quite crowded, and isn't a very safe place for an expensive communications sat, and yet we have a couple there now. Although most of the dead sats there are significantly inclined, so it's not like they're constantly in the box. But still it seems strange that they'd even use that orbital slot.

I'm also still curious whether all of the sats in there were actually placed there, or if they were able to decay there on their own, rather than oscillating back and forth like the tracking programs predict. I notice a couple GOES sats in the list. I think Kelso keeps archival keps for at least some GOES sats. Might be interesting to look through the old keps to see how those sats got there.

Anyway, neat. I must admit being surprised at this. I've always heard about these spots, but never really believed that they could really be as stable as people suggested, but it's pretty clear that I was wrong. I still have my doubts that objects would end up there if they weren't placed there, but I'll probably end up wrong on that too. I think tomorrow I'll look up some of those GOES sats.

 

[skysurfer]

From the horse's mouth... Intelsat is going to try to re-contact the bird 5/3 in the AM (around 4)... If that fails they are going to try to blow-out the transponders so that the interference issue goes away.... key word there is "try"...

Looks like the horses mouth is right on the money! I'm going over G12 this morning in my bimonthly arc check and all of a sudden there is interference galore as seen on my spec analyzer. The interference looked like the time one of my norsat LNBs went out, so I was cussing that I am losing another Norsat LNB! I tried the other polarity (different norsat LNB since I run an orthogonal setup on that dish), same issue with spikes in the signal where it shouldn't be.

I pulled over another c-band dish to g15 to check things out, same interference issue.

It all of a sudden hit me -- this thread! It was like 4:15'ish ET on May 3rd and then it made sense! I moved my dish to g13 - all was fine. I moved my dish to AMC-10. all was fine. Only G12 and AMC-11 are affected with G12 more so than AMC-11.

I"m going to try to flip camcorder my spec analyzer screen to capture video of the interference spikes that intelsat is transmitting.

EDIT: missed it - ended about 4:30'ish ET AM just as the power to the flip camcorder was turned on. I'll monitor for a few minutes and see if Intelsat tries again or if they think they've sent enough carriers that it would have worked or failed in those 15 minutes of transmissions.

The carriers were wavy, not broadband and were stronger than the existing G12/AMC-11 signals. They were all centered on roughly all the transponders at once.

 

[B.J.]

Very;

Objects at the western liberation point (105W)

CLASSIFICATION OF GEOSYNCHRONOUS OBJECTS -- ISSUE 11_

Well, after an afternoon of manual searching, having searched all the common names of TVRO sats except Galaxy, (which I forgot), I was just about to post that I found 3, Satcom C5, GSTAR 1, and GSTAR 3. I think your list is a wee bit more complete. THANKS.

With just 3 there, I still had my doubts, thinking maybe those were still under control, but with all those there, it does seem like a crowded spot.

..........

I'm also still curious whether all of the sats in there were actually placed there, or if they were able to decay there on their own, rather than oscillating back and forth like the tracking programs predict. I notice a couple GOES sats in the list. I think Kelso keeps archival keps for at least some GOES sats. Might be interesting to look through the old keps to see how those sats got there.
....
....... I still have my doubts that objects would end up there if they weren't placed there, but I'll probably end up wrong on that too. I think tomorrow I'll look up some of those GOES sats.

Well, I downloaded the historical GOES 6 data from Kelso, but I didn't have to use it (luckily, because there seems to have been a format change at some point in the keps, which is confusing me). Reason I didn't have to use the historical keps is that although the above lfvn.astronomer.ru "Objects in a libration orbit around the Western stable point" lists GOES-6 as being one of those sats at 105, I just ran the current keps for GOES-6, and it isn't really "AT" 105, it is in one of those oscillating back and forth things, where it is moving back and forth between 135.6W and 73.7 over about a 2 1/2 year period. Right now it's actually at 116.8W, not 105W.

So, while I haven't tried any other of those sats in the big list yet, I'm back to thinking that unless the sat is actually moved to, and placed at 105 in a stable orbit, that it will NOT drift there and stop, at least within any reasonable stretch of time, but instead, just continue to wobble back and forth from where it started drifting to that amount on the other side of 105.

This all explains something I read a few days ago in another document. Ie I found one document, which didn't list sats by name, but mentioned that there were several sats in orbit around the western point, some sats in orbit around the eastern point, and some sats in orbit around both east and west points. I didn't really understand this at the time, but now it makes sense. Ie I'm guessing that using the hills and valleys analogy, that there must be a higher hill on one side of 105 than the other, and some sats might be able to get over the shorter hill, and make it over to the eastern point, go past that to the higher hill, then back past the eastern point, over the short hill again, past the western point, to the higher hill which it can't go over, etc, etc. Ie, sort of trapped by both stable points, but not able to keep circling the earth, but also not stopped at any one point.
Then again, some sats have enough motion that they make it over both short and high hills, and they keep circling the earth forever.

Anyway, I'm going to continue to play with these sats, but it's all starting to make sense to me.

Neat stuff.

EDIT: One other thing, the above explained a few of the data columns in that russian chart posted, ie the
?? column seems to be the total number of degrees of the back and forth wobble, ie the above 135.6 - 73.7 = 61.9, compared to the 61 in the chart.

?min column corresponds to my 135.6, except in eastern degrees

?max column corresponds to my 73.7, except in eastern degrees

Given that, you can see in the chart, the number of sats that are actually trapped close to 105. Ie there are only 5 sats in the list within a couple degrees of 105, and add to that the 2 that I found yesterday that weren't on the list. So there are a few that seem to be trapped there, but I'm guessing that they were actually placed there, or happened to start their drift while near 105.

EDIT2: I also found an interesting document... http://75.125.200.178/~admin23/siteadmin/images/files/file_371.pdf
Near the end, on page 120, there is an interesting graph of libration objects, which shows the range of oscillation.

EDIT3: I also figured out the the 2 sats that I found that weren't on the list, ie Satcom C5, and GSTAR-1, are actually accounted for. Satcom C5, is actually Aurora-1, which IS on the list. Also, GSTAR-1, while at 105, is apparently STILL UNDER CONTROL, according to the above space agency document linked just above, so it's not really drifting yet.

 

[nelson61]

This might shed some more light on it.

It is their index page on the subject with lots more info

CLASSIFICATION OF GEOSYNCHRONOUS OBJECTS -- ISSUE 11

 

[Gen.Blue]

I called Intelsat to get an update on the G15 situation. They told me that their attempt this morning to re-gain control or disable the satellite failed. They have a contingency plan, but I don't have any details.

 

[JimmyMcGee]

Well, I downloaded the historical GOES 6 data from Kelso, but I didn't have to use it (luckily, because there seems to have been a format change at some point in the keps, which is confusing me). Reason I didn't have to use the historical keps is that although the above lfvn.astronomer.ru "Objects in a libration orbit around the Western stable point" lists GOES-6 as being one of those sats at 105, I just ran the current keps for GOES-6, and it isn't really "AT" 105, it is in one of those oscillating back and forth things, where it is moving back and forth between 135.6W and 73.7 over about a 2 1/2 year period. Right now it's actually at 116.8W, not 105W.

So, while I haven't tried any other of those sats in the big list yet, I'm back to thinking that unless the sat is actually moved to, and placed at 105 in a stable orbit, that it will NOT drift there and stop, at least within any reasonable stretch of time, but instead, just continue to wobble back and forth from where it started drifting to that amount on the other side of 105.

This all explains something I read a few days ago in another document. Ie I found one document, which didn't list sats by name, but mentioned that there were several sats in orbit around the western point, some sats in orbit around the eastern point, and some sats in orbit around both east and west points. I didn't really understand this at the time, but now it makes sense. Ie I'm guessing that using the hills and valleys analogy, that there must be a higher hill on one side of 105 than the other, and some sats might be able to get over the shorter hill, and make it over to the eastern point, go past that to the higher hill, then back past the eastern point, over the short hill again, past the western point, to the higher hill which it can't go over, etc, etc. Ie, sort of trapped by both stable points, but not able to keep circling the earth, but also not stopped at any one point.
Then again, some sats have enough motion that they make it over both short and high hills, and they keep circling the earth forever.

Anyway, I'm going to continue to play with these sats, but it's all starting to make sense to me.

Neat stuff.

EDIT: One other thing, the above explained a few of the data columns in that russian chart posted, ie the
?? column seems to be the total number of degrees of the back and forth wobble, ie the above 135.6 - 73.7 = 61.9, compared to the 61 in the chart.

?min column corresponds to my 135.6, except in eastern degrees

?max column corresponds to my 73.7, except in eastern degrees

Given that, you can see in the chart, the number of sats that are actually trapped close to 105. Ie there are only 5 sats in the list within a couple degrees of 105, and add to that the 2 that I found yesterday that weren't on the list. So there are a few that seem to be trapped there, but I'm guessing that they were actually placed there, or happened to start their drift while near 105.

EDIT2: I also found an interesting document... http://75.125.200.178/~admin23/siteadmin/images/files/file_371.pdf
Near the end, on page 120, there is an interesting graph of libration objects, which shows the range of oscillation.

EDIT3: I also figured out the the 2 sats that I found that weren't on the list, ie Satcom C5, and GSTAR-1, are actually accounted for. Satcom C5, is actually Aurora-1, which IS on the list. Also, GSTAR-1, while at 105, is apparently STILL UNDER CONTROL, according to the above space agency document linked just above, so it's not really drifting yet.

:up:up Thank you BJ, My Inner(and Outer) Nerd is intrigued as much as you are.

I called Intelsat to get an update on the G15 situation. They told me that their attempt this morning to re-gain control or disable the satellite failed. They have a contingency plan, but I don't have any details.

Maybe they will launch a missile to take it out. That would be cool!

 

[B.J.]

This might shed some more light on it.

It is their index page on the subject with lots more info

CLASSIFICATION OF GEOSYNCHRONOUS OBJECTS -- ISSUE 11

THanks. A lot of the links there are to the same figures that were in the url I posted, however it's a lot easier to get to the pages from this index.
Most interesting to me was the link to
"Longitude history of the objects librating around the two stable points" , ie CLASSIFICATION OF GEOSYNCHRONOUS OBJECTS -- ISSUE 11
If I understand these, the points of greatest slope are at the libration points, and the highest and lowest points are where the sat can't quite get over the "gravity hill", and the inflection between the two high slope points is slowing down while going over the smaller "gravity hill" .
Neat diagrams.
Thanks.

 

[eurosport]

Test Pattern...

If Intelsat can't shut it off I think it would be cool if they transmitted a G-15 identifier screen using a steerable dish to follow it 'till they lose contact. Then we could track it too with our motorized C-band dishes! :up

 

[turbosat]

Drifting satellite @115W story

Found on another site, but it's a dang interesting space story. Seems Galaxy 15 lost its ears early in April and started drifting east along the satellite arc (LOOKOUT AMC11 lol) fully broadcasting but not receiving control commands.

from "msnbc"
: Out-of-control satellite threatens spacecraft - Space.com- msnbc.com

Zombiesats....what's next.

 

[cracklincrotch]

Pigs in Space?

 

[guapoharry]

...Maybe they will launch a missile to take it out. That would be cool!

Take it out, meaning what?
Why create debris in geosynchronous orbit?

 

[JimmyMcGee]

Take it out, meaning what?
Why create debris in geosynchronous orbit?

Passing Comment. I was basically referring to their almost lack of options at this point.

Obviously they wouldn't want to create debris, so they wouldn't "blow it up" But they could bounce it out of the orbit towards the sun. It would be like throwing a basketball towards and hitting another basketball that's already in the air.

Seriously though, obviously not the solution just making a comment. This idea of someone shooting a rogue zombie sat out of the sky seemed like an interesting though, nothing more. :

 

[tvropro]

More on the story.

FOXNews.com - Intense Solar Storm Spins Satellite Out of Control

 

[B.J.]

If Intelsat can't shut it off I think it would be cool if they transmitted a G-15 identifier screen using a steerable dish to follow it 'till they lose contact. Then we could track it too with our motorized C-band dishes! :up

Of course that would require Intelsat transmitting a signal illegally in a direction that would cause interferrence with other sats, and would be repeated by the functional sat as well, so in addition to G15 messing up AMC-11's service, Intelsat itself would be messing it up?

I was about to suggest that G15 was already transmitting a beacon signal that would identify it, however I just looked at the beacon list, and apparently G15 doesn't have a beacon? This is a bit strange, because other than relying on USSTRATCOM, who I assume must use radar to locate sats, I'm not sure how Intelsat will be able to accurately locate the sat, unless it's repeating a signal.

Because of this, your idea above, might be the best way for them to keep track of where the sat actually is, ie perhaps Intelsat would rent out a portion of a transponder on the sat G15 is drifting near, and very accurately (big dish) send a weak signal just to G15, so that they can keep track of where it is. Obviously not necessary to use the bandwidth required for a video slate, but that might make it easier for them. Of course, there will be periods when the 2 sats will be too close together to avoid interference, and both sats will retransmit the slate, ie they have to cross paths at some point, but when that happens, they have bigger problems than not accurately knowing where G15 is. One thing that might help a bit is that the inclination of G15 seems to be increasing by about 0.002 deg/day , so by the time G15 is too close to AMC11 to selectively uplink to only one of them, the inclination should be up in the 0.3 deg range I think, and maybe that would limit interference to twice a day? Or perhaps if they allow AMC11 to incline a bit, perhaps they could be kept separat by a couple tenths of a degree while crossing???? That's probably not enough to eliminate dual illumination though.


I wonder when we'll see reports of whether their high power attempt to shut the thing down actually worked?

Someone mentioned sending up a rocket to blast the thing out of orbit, which is obviously not an option, but something similar that MIGHT be an option would be to offer this sat to the DOD as a test target for some super secret laser weapon. I don't know if such a weapon exists, but if it does, not that they could or should destroy it, it seems like they might be able to knock out the solar cells with a an overload. It would be some free target practice for the military. They wouldn't even have to admit that they did it, Intelsat would just suddenly find that the thing was no longer transmitting.

 

[photoman76]

More on the story.

FOXNews.com - Intense Solar Storm Spins Satellite Out of Control

Typical FoxNews. They can't even get the headline correct. The satellite didn't "spin".

 

[B.J.]

Typical FoxNews. They can't even get the headline correct. The satellite didn't "spin".

Also, the article said:

"Depending on their position at the time of failure, these satellites tend to migrate toward one of two libration points, at 105 degrees west and 75 degrees east. Figures compiled by XL Insurance of New York, an underwriter of space risks, say that more than 160 satellites are gathered at these two points, which Bednarek described as the orbital equivalent of valleys. "

From the discussion, over the past few days, it's clear that only 5 sats are currently located "AT" these two libration points, not "more than 160", but I guess that's what fox gets for using an insurance company as a source of scientific data. I wonder if SES has to pay a higher rate for insuring AMC-15 and -18, since they think there are 37 sats at 105?

 

[alk3997]

Obviously they wouldn't want to create debris, so they wouldn't "blow it up" But they could bounce it out of the orbit towards the sun...

Not to shoot down (pun intended) another idea, but here is the way the orbital mechanics work. You can't change the laws of physics...

If you add energy to the satellites orbit (in other words, increase its orbital speed relative to the Earth), the satellite will gain altitude but still be in orbit. The reverse is true as well - if you decrease the orbital speed, the satellite will fall to a lower (and smaller radius) orbit. Since the radius is smaller the orbit is actually faster in completing one orbit (even though you decreased orbital speed to get to the new orbit).

So, to "bounce it out of the orbit towards the sun", you would have to add enough energy (increase the speed) of the orbit to a point that the satellite was out of geostationary orbit and then continue until the orbit was out of the gravity well of the Earth (hyperbolic trajectory relative to the Earth). The problem with that is you are still in an orbit 1AU distant from the Sun (the same as Earth's orbit).

Therefore you would have to start decreasing your orbital energy relative to the Sun to a point that the lowest part of the orbit now starts decreasing and the satellite gets closer to the Sun. The closest we've gotten a spacecraft to the Sun is the Messenger probe about to go into orbit around Mercury and that took multiple planetary flybys to reduce speed. This is because of how much energy it takes to reduce orbital velocity. The Sun's gravity well is very very large but we are in an orbit already and therefore you have to null-out that orbital velocity before something would fall "towards the Sun."

I know you were trying to start a conversation with your comment - so how's that for starters from the physics side? When geostationary satellites have warp drives, then we can talk about aiming for the Sun!

Andy

 

[eurosport]

Typical FoxNews. They can't even get the headline correct. The satellite didn't "spin".

Not the satellite, but with Fox... nah....nevermind.....

 

[JimmyMcGee]

Not to shoot down (pun intended) another idea, but here is the way the orbital mechanics work. You can't change the laws of physics...

If you add energy to the satellites orbit (in other words, increase its orbital speed relative to the Earth), the satellite will gain altitude but still be in orbit. The reverse is true as well - if you decrease the orbital speed, the satellite will fall to a lower (and smaller radius) orbit. Since the radius is smaller the orbit is actually faster in completing one orbit (even though you decreased orbital speed to get to the new orbit).

So, to "bounce it out of the orbit towards the sun", you would have to add enough energy (increase the speed) of the orbit to a point that the satellite was out of geostationary orbit and then continue until the orbit was out of the gravity well of the Earth (hyperbolic trajectory relative to the Earth). The problem with that is you are still in an orbit 1AU distant from the Sun (the same as Earth's orbit).

Therefore you would have to start decreasing your orbital energy relative to the Sun to a point that the lowest part of the orbit now starts decreasing and the satellite gets closer to the Sun. The closest we've gotten a spacecraft to the Sun is the Messenger probe about to go into orbit around Mercury and that took multiple planetary flybys to reduce speed. This is because of how much energy it takes to reduce orbital velocity. The Sun's gravity well is very very large but we are in an orbit already and therefore you have to null-out that orbital velocity before something would fall "towards the Sun."

I know you were trying to start a conversation with your comment - so how's that for starters from the physics side? When geostationary satellites have warp drives, then we can talk about aiming for the Sun!

Andy

I am definitely not a rocket scientist but that makes sense. I'm just some shclub on a forum, my understanding right now is minimal and I am simply learning.

Also, I obviously know that my solutions are silly but that's sort of the point.

In that vain, the next option they have is to get NASA or maybe Virgin Galactic to charter a space ship, fly next to the run away satellite, open the door and grab it with a hook and bring it back to Earth.

 

[alk3997]

I am definitely not a rocket scientist but that makes sense. I'm just some shclub on a forum, my understanding right now is minimal and I am simply learning.

That's alright - part of going out to a forum is to learn. It is why I'm here.

As far as Virgin Galactic is concerned, remember they only go to Mach 3 (suborbital). To reach low Earth orbit, you have to hit the equivalent of Mach 25. I say equivalent since there is really no Mach number when you have no atmosphere. So, they may not be your best solution...

If you wiki some of the Apollo stuff, you'll see the velocity and energy needed to return from the Moon. For geostationary, just reverse most of the energy that an Ariane or Proton puts into the satellite to get it to geostationary orbit. That's all you have to do...

Andy