AMC-9 satellite breaking up in GEO

[tater]

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

 

[_Augustus_]

Hopefully this spreads awareness of space debris problems.

[Bill Phil]

Oooh... ouch. It was up there a long time, though. Long time scales lead to increased likelihood of collisions.

Also, Geostationary orbit is a crowded area. Lots of traffic (but it is a big area, even so). Collisions like that are very rare. And there's no reason to suspect space debris (other than the debris the satellite gives off). Could've been some weird things going on. Lots of stuff up there, including asteroids, other satellites, junk, and of course just the environment of space itself. Maybe some connectors just gave out? Of course, it could be a collision, and is likely so. Even so, I wouldn't go crazy about Kessler Syndrome just yet... Even if it happens, most of the debris will be limited to GEO. Molniya orbits, and figure 8 orbits (it's a figure 8 on the ground, hard to describe) would still be fine.

/bad joke

Maybe it's secretly a space carrier or something. Which would imply that that isn't debris...

/bad joke

[_Augustus_]

6 minutes ago, Bill Phil said:

Lots of stuff up there, including asteroids

No............

[tater]

Rocks are always a possibility, even if the probability of such a strike is infinitesimal. 

[qzgy]

1 hour ago, tater said:

Rocks are always a possibility, even if the probability of such a strike is infinitesimal. 

Whether it be infinitesimal, its still a possibility.

[Green Baron]

So, Kessler syndrome up and running ?

[Nibb31]

In GEO, everything is going at the same speed in the same direction, so collisions are unlikely. If something slows down or speeds up, then it is no longer in GEO and will only briefly intersect with GEO. Considering the distances and volumes (we are talking about refrigerator-sized objects in an orbital formation that is 6 times the diameter of the Earth), chances of collision are infinitesimal.

In the video, the round objects that you see are GEO sats (small specks of light that are magnified into round blobs is all we can see at this distance). The line objects are stars in the background. We see a couple of LEO objects going in different directions, but they are at very different altitudes.

It seems that AMC-9 gets caught up by a formation of other sats, which means that it had already lost control when this video was taken (which is probably the reason why this video was taken). There seems to be a series of flashes shortly after the pass of the other sats (which might or might not have been caused by a collision), following by a something separating from AMC-9.

 

[Scotius]

Maybe it lost positioning control and rotated itself to death, like that japanese sat a while ago? I think i've seen some brightness changes - but it might be atmospheric disturbances.

[tater]

Flares can also just be reflections. This can be just the geometry of light hitting the satellite, or it might just be that it is tumbling.

[Green Baron]

Yeah, that's all clear, though some of these fridges weigh have a mass of several tons.

What I meant, as the fridges grow older more of them can fail, producing clouds of fridge remains that could fill up the girdle or at least make the gaps smaller. Probabilities for collisions don't go down, it's not getting safer. Speed differences can still be a few hundred m/s for parts on slightly elliptical orbits, as caused by accelerating parts of a former fridge through rotation/explosion/whatever, enough to make a working fridge join the trend i think.

 

[Bill Phil]

10 hours ago, _Augustus_ said:

No............

An asteroid (not even that small of one) flew by Earth at an altitude less than GEO. That was recent too.

Then there are micrometeoroids. A pretty big threat of we have a satellite up there for years.

Edited July 2, 2017 by Bill Phil

[Kerbart]

11 hours ago, Bill Phil said:

Also, Geostationary orbit is a crowded area. Lots of traffic (but it is a big area, even so). 

It's a band at 0° inclination that has a 264,000 km (164,000 mi for the metrically handicapped) circumference. As you mentioned, plenty of space!

However, the prime use is communications satellites, and most of them operate in the same frequency bands. That makes signal crossover a risk and THAT requires an x° seperation between the various comsats. And that, in turn, does make it crowded, in the sense that there is very limited space for new satellites. 

I don't think there's that much risk collision-wise, though.