
Zombie Satellites Return from the Graveyard - sohkamyung
https://spectrum.ieee.org/tech-talk/aerospace/satellites/zombie-satellites-return-from-the-graveyard
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walrus01
One of the things persons not involved in the industry find interesting, is
that in the entire history of manned spaceflight, no human has ever visited
geostationary orbit.

I have talked to a number of people who were mistakenly under the impression
that humans occasionally conduct repairs on telecom satellites.

Also this is the first time a (non-classified, that we know about) spacecraft
has visited and photographed another satellite in geostationary orbit.

~~~
onion2k
_One of the things persons not involved in the industry find interesting, is
that in the entire history of manned spaceflight, no human has ever visited
geostationary orbit._

No one has ever stopped in geostationary orbit, but you have to go past where
geostationary satellites stay to get to the moon, so quite a lot of people
have really.

~~~
emiliobumachar
Excuse my meta-pedantry, but an orbit is not defined only by a height, it
requires also an appropriate velocity.

[https://en.wikipedia.org/wiki/Orbit](https://en.wikipedia.org/wiki/Orbit)

~~~
walrus01
Well yes, you certainly wouldn't want to go to a circular geostationary orbit
and then expend a ton of fuel to thrust retrograde, cancelling out all your
velocity, which would result in falling straight into the earth. Definitely
not like people would think of in common sci-fi where things can just hang
motionless in space.

Being in circular geostationary is defined as also having enough velocity for
your orbit to remain circular.

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ethagnawl
This area of research and application is fascinating and, as the article
alludes, will only become more important in the coming decades.

I also read a related story[0] recently that others may find of interest: A
hobbyist was able to track down a satellite whose EOL was supposed to be in
_1972_ by using a beefed up HAM radio to scour the sky for its RF.

[0] - [https://www.npr.org/2020/04/24/843493304/long-lost-u-s-
milit...](https://www.npr.org/2020/04/24/843493304/long-lost-u-s-military-
satellite-found-by-amateur-radio-operator)

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mhandley
There really needs to be mandatory insurance for GEO satellites. If your
satellite fails to reach the graveyard orbit, the insurance pays the towing
fees.

~~~
RandomBacon
Reminds me of the series _Planetes_. I would definitely be a garbage man if it
meant working space and EVAs.

~~~
sohkamyung
Not quite the same, but I'm reminded of the short lived show "Salvage 1",
starring Andy Griffith [1]

[1]
[https://en.wikipedia.org/wiki/Salvage_1](https://en.wikipedia.org/wiki/Salvage_1)

~~~
joshstrange
Interesting, I hate that these types of shows appear to be lost to the ages. I
can't find it to buy (there are a handful of episodes available for purchase
on DVD on Amazon for something like $17/per) and I don't see it come up on
streaming services either.

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dekhn
A neighbor of mine worked on the refuelling mission described here. Basically
he uses a library of CAD designs to assemble standardized components for
satellites. The more I learn about satellite operations the more impressed I
get. My favorite was a zombie satellite that woke up after 25+ years and
started transmitting again. Apparently, the solar panels had broken in such a
way that they transmitted power through the battery (even though the battery
could no longer hold a charge), so periodically the satellite would be in
illumination and transmit (but it had a very weird pattern because the
satellite was spinning out of control).

It still blows me away that most satellites, if they have a glitch like losing
contact with the ground, will go into "Safe" mode- solar panels fully
deployed, directly facing the sun, so it's likely there's enough power to
recontact. I have enough trouble implementing a PID-driven motor on my arduino
that it impressed me what people can do in space.

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erwinh
Lots of material up there, would be interesting to prospect what more tech
could be appropriated there for new use-cases.

At [https://space-search.io](https://space-search.io) by applying the orbit
duration filter lower than 1 (i.e. above geostationary) you can get a good
picture of all the satellites currently in that kind of graveyard orbit.

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gruez
>Graveyard orbits comprise paths at least 300 kilometers above the
geosynchronous region, giving the zombie spacecraft room to have their orbits
incrementally ground down by the gravity of the sun and moon.

Why is the graveyard orbit _higher_ than the orbit for operating satellites?
Doesn't that mean when the orbit eventually decays, that the satellite will
eventually fall back into the orbit where all the operating satellites are?

~~~
m4rtink
I guess to prevent dead satellites interferring with new ones comming to GEO
from below ? Not sure if that's right though as many GEO insertion orbits
often have apogeum much higher than the final GEO altitude.

~~~
walrus01
Assuming a telecom satellite is still controllable at EOL, the TWTAs will be
powered off, leaving only the narrow band S/L band command and control channel
operational while the orbit is raised slightly.

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raxxorrax
I don't quite understand why they don't decrease their orbit to burn up in the
atmosphere. It would certainly be the Kerbal way.

Are the satelites too large to burn up?

~~~
Monroe13
According to some Wikipedia research “De-orbiting a geostationary satellite
requires a delta-v of about 1,500 metres per second (4,900 ft/s), whereas re-
orbiting it to a graveyard orbit only requires about 11 metres per second (36
ft/s).”

[https://en.m.wikipedia.org/wiki/Graveyard_orbit](https://en.m.wikipedia.org/wiki/Graveyard_orbit)

~~~
raxxorrax
Huh, wouldn't have guessed it to be that much, but it makes sense. De-orbiting
gets cheaper the higher your orbit is and a geo stationary orbit is high, but
not that high.

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saul_goodman
I'll just leave this here: [http://orbitofshame.org](http://orbitofshame.org)

