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/

by robin_reala • 9 years ago

79 38 9 years ago

arstechnica.com

yummmuy• 9 years ago

If only we knew the details ...

wglass• 9 years ago

"space weather problem" ?

knz• 9 years ago

https://en.m.wikipedia.org/wiki/Space_weather

I assume electronics that are failing due to shielding that has failed?

planteen4• 9 years ago

A space weather problem would be a single event upset. Something got flipped to the wrong state and could have burned up (e.g., power electronics). You protect designs against this with circuit design but can't use shielding. Shielding is to reduce total ionizing dose, not single event upsets.

tmsldd• 9 years ago

It looks like structural fault.. two possibilities here: a) debris collision and, b) hardware fault during maneuvering (e.g. Fuel tank explosion, solar panel or antena detachement). The later I think is more likely to happen towards the end of the life of the hardware.. which seems to be the case.. but in other hand we could expect a cloud of smaller debris floating around..

ge96• 9 years ago

That video is cool

Animats2• 9 years ago

Cleaning up geosync orbit is going to be tough.

There's a proposal to remove small objects from low earth orbit by shining an 10KW or so earth-based laser at them for a few hours. This exerts enough light pressure to drop their orbit deeper into the atmosphere, where they slow further, re-enter, and burn up. That's probably the most cost-effective approach proposed so far. Now that solid-state lasers in the 50KW range are available, this looks like a viable option.

planteen4• 9 years ago

How does an Earth based laser bring something closer to Earth with radiatipn pressure rather than pushing it further away? And how does that work in GEO? The typical disposal method there is to go up to a graveyard orbit, not down to the atmosphere. The atmosphere is very far away from GEO. You are looking at 35,000 km in GEO while the ISS is skimming the atmosphere in LEO at 400 km.

zdkl• 9 years ago

Once you destabilise the orbit you can be pretty sure things will end either in a ball of fire somewhere in the upper atmosphere or slingshotting into space. I wouldn't want to be in the path though.

robin_reala• 9 years ago

Debris still rises over the horizon, so lasing the front of the object will push it both out and back. If you can balance it so that the back degrades the orbit more than the out increases it then you’re good.

Terr_2• 9 years ago

How does an Earth based laser bring something closer to Earth with radiatipn pressure rather than pushing it further away?

It changes the shape of the orbit. Shooting sideways is hard (more atmosphere) but pushing it away from the center of the earth works too: The orbit becomes less circular and more elliptical. While the higher point (apogee) is further away than before, the lowest point (perigee) is closer.

Lower the perigee enough, and the satellite starts grazing the atmosphere. That's what really bleeds off energy, and causes the orbit to shrink overall.

And how does that work in GEO?

I'm not sure. At that distance you can't rely on the same subtle destabilization, nor really hit it from any angle but "below".

emj• 9 years ago

Yeah, the linear scale graph from wikipedia does make GEO seem very large. I'm guessing wildly here but most things in GEO should be orbiting in the same(ish) speed and direction, which makes a cascade as those we will get in LEO less likely. Still makes you worried though..

https://commons.wikimedia.org/wiki/File:Orbitalaltitudes.jpg

nthcolumn2• 9 years ago

I read another article yesterday with Vector gushing about being able to launch two per week and just thought 'more space-junk' and that's just the delivery system. Some of these are launching multiple payloads - some no bigger than a briefcase. We need some sort of international treaty on corridors and such. Anything in the flight corridor gets the laser tractor beam.

Tepix• 9 years ago

The relative speeds of pretty much all objects that are in GEO orbit is probably very small - after all they all started out orbiting the earth in the same direction at the same speed. Shouldn't this make collecting debris much, much easier? Navigating within the orbit could be done using electric propulsion. Of course such an undertaking would still be very expensive given that once you have collected a bunch of debris you need to deorbit it.

empath75• 9 years ago

When people talk about how crowded geostationary orbit is, keep in mind, that the surface area of a sphere 86,000 km above the earth is about 30 times larger than the surface area of the earth itself.

function_seven• 9 years ago

That’s relevant for geosynchronous orbits, but for geostationary, the circumference is 7 times longer than the equator’s distance.

mirimir2• 9 years ago

OK, I see that AMC-9 is flashing at a more-or-less regular rate, throughout the video clip. But other geostationary satellites in the field, such as the four bright ones near the beginning of the clip, don't flash. This is because AMC-9 is spinning, right? Some flat surface, perhaps the PV array, is reflecting more of the sun's light.

I'm guessing that some of the attitude-control thrusters malfunctioned. Maybe that's what rendered the satellite unresponsive.

But in any case, excessive rotation could fragment the satellite. From the observed rotation rate and the size of the satellite, one could estimate a range of relative fragment velocities. And if one knew the video's angular field of view, one could estimate observed relative fragment velocities. I don't know that, but they seem smaller than velocity differences between AMC-9 and other geostationary satellites.

nthcolumn2• 9 years ago

https://www.ses.com/our-coverage/satellites/315

So at that rate how fast is it spinning? Says it is fairly large satellite - car sized?

mrpjdog• 9 years ago

It's how fast it is spinning yes but it there could be multiple surfaces that reflect more brightly.

I actually work at a telescope where we're in the business of tracking satellites. Its boring work, but it's good as a summer job, and the professor it's under has me working on much cooler projects. I'll have to find the ephemerides of the sat and point out scope there.

rasz• 9 years ago

"The AMC-9 could have been attacked by something"

Are we sure its a real satellite? and real news?

New Cloverfield franchise film is coming out in October: https://en.wikipedia.org/wiki/God_Particle_(film)

J. J. Abrams and his company Bad Robot is known for doing this type of guerrilla marketing ( http://cloverfield.wikia.com/wiki/Viral ), they did it for both original Cloverfield and for 10 Cloverfield Lane. It included fake YT news clips, fake websites for fake satellite/oil/power companies, fake press releases, the whole nine yards.

Fake satellite: http://cloverfield.wikia.com/wiki/ChimpanzIII

ExoAnalytic was founded in 2008, the same time Abrams ran his first viral campaign for the Cloverfield.

More about the tangled lore and extent of the viral marketing: https://www.youtube.com/watch?v=FtaCF87_d0c

A large satellite appears to be falling apart in geostationary orbit

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