I was trying to look up GOES-17 in Spaceflight101 but got sidetracked in the search result and ended up reading this thread about AMC-9, which links to the YouTube video Rough cut video of AMC-9 satellite on Friday night.. The video's notes say:

On the morning of June 17th, the Luxembourg-based satellite operator SES lost control of a large satellite in geostationary space. A few days ago ExoAnalytic Solutions began seeing the AMC-9 satellite fragment. For annotated still images, go here: https://arstechnica.com/science/2017/07/a-large-satellite-appears-to-be-falling-apart-in-geostationary-orbit/

In the sidebar, YouTube recommended a second video; Telkom-1 Satellite Debris Incident.

The first video shows AMC-9 in GEO tumble and break up, and the second shows the moment shows the moment of an actual explosion or impact.

These are fairly rare events to capture by accident.

Question: For expensive, commercial communications satellites in GEO, are they being watched all the time? Or at least at night?

Video's remind me of Scott Manley's video introduction, sans catchy soundtrack (see for example How Well Did SpaceX's new Falcon 9 Work?):

  • $\begingroup$ GOES-17 is also called GOES-S; searching for that instead in Spaceflight1010 worked nicely. $\endgroup$
    – uhoh
    Commented May 24, 2018 at 13:19

2 Answers 2


It seems that the company ExoAnalytic Solutions regularly observes high- orbiting satellites (MEO, HEO, and GEO), using the data to provide tracking, ensure they are at the right spot, and provide data in the event of an emergency. They have 200 telescopes dedicated to the effort, which seems to indicate that they can't observe every satellite all the time, but can observe most satellites most of the time. The price seems very small relative to the cost of a satellite, so it seems likely they are considered a good investment just in case something happens.

It seems from the website they focus almost completely on Geosynchronous orbiting satellites. I doubt they can observe every satellite all the time, but they probably do a pretty good job of viewing most of them most of the time, especially if they pay the price to have the observation nearly constant.


As a partial answer: from my experience as an astronomer, I can say it's impossible to constantly observe objects (at least in the optical) because of:

  • Cloudy weather, which obscures objects from view
  • Objects crossing into the daytime sky

That doesn't preclude someone setting up the capabilities of constant optical observation given good weather and night skies, and as PearsonArtPhoto points out ExoAnalytic Solutions seems to have this capability or at least something close to it.

That being said, I know that there is consistent radar tracking of both satellites and space debris. Here is a link to such a system being built currently in the Marshall Islands. I'm not as familiar with the limitations and capabilities of radar tracking, but if I'm not mistaken this tracking would work both day and night, and works even during cloudy weather. (If I'm wrong on this, please let me know.) However, I don't believe there is full sky coverage of radar able to track satellites, so this wouldn't provide constant tracking.

  • 1
    $\begingroup$ Very high radar frequencies may be disturbed by thick clouds. Double distance requires 16 times the power, the tyranny of the radar equation, necessary beam power is proportional to the fourth power of distance. $\endgroup$
    – Uwe
    Commented May 28, 2018 at 9:28

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