|
Why We Can't Shoot The Zombie (Satellite) Today
By Doug Mohney - July 13, 2010
Owned by Intelsat, the Galaxy 15 "zombie" satellite continues to drift around in geosync orbit in a "stable and predictable" path right into the broadcast zones of two more satellites, reports Space.com. It is time to man up and start working on a solution for this and future problems.
Galaxy 15 -- a.k.a ZombieSat -- went bad back in April, losing contact with ground controllers but continuing to transmit in the C-band as it started drifting out of its assigned orbital slot at 133 West longitude. Attempts to force it into a safe shutdown mode have failed, leaving Intelsat into hoping that either the satellite automatically flips itself into a non-broadcasting safe mode or the satellite drifts into an orientation pointing its solar panels away from the sun and it runs out of power.
Back in May, ZombieSat crossed into the broadcast area of SES World Skies AMC-11, forcing SES to perform a series of maneuvers with AMC-11 to avoid interference. This month, ZombieSat has the strong potential to interfere with broadcasts coming from Galaxy 13 and Galaxy 14, two other Intelsat satellites that provide video services to U.S. customers, followed by a drift into Telesat's Anik F3 territory.
Plans to mitigate problems include pointing antennas away from ZombieSat until it moves out of range and maneuvering satellites around until the wayward broadcaster continues on -- not something any operator really wants to do, since fuel is orbital life.
The best way to treat ZombieSat is to call it what it really is: A very obnoxious piece of space junk that needs to be removed from orbit. But the range of active disable options available today is limited and fraught with political headaches.
The United States, Russia, and China have demonstrated kinetic anti-satellite weapons (i.e. missiles) in low earth orbit. While the capability likely exists to reach satellites in GEO, simply blowing up ZombieSat would be a dubious undertaking for the dual reasons that no nation would be willing to demonstrate such a capability -- causing a serious arms control headache -- and that a successful intercept would leave a cloud of debris floating around in the prime real estate of GEO.
In theory, either a ground or aircraft-based laser could be used to target ZombieSat's solar panels, degrading their capacity to generate electricity and in-effect depowering the rogue satellite. Some reports credit the Chinese with having a high-power anti-satellite laser and the U.S. has run laser tests against a satellite in LEO. Reaching up to GEO and "touching" ZombieSat could be possible with existing U.S. government assets, but if successful would also cause gnashing of teeth on the arms control front.
Other alternatives only exist on the drawing board and the U.S. has only started to fund more research into cleaning up space debris. A ground-based laser to nudge smaller LEO-based debris into the atmosphere for burn-up has been under discussion, but that wouldn't do the trick for something as large as ZombieSat in GEO-land.
More practical -- but unlikely to happen soon -- would be to launch an intercept mission with a small payload to attach a something-or-another to ZombieSat to either boost it out of GEO into a higher parking orbit or to drag it down out of GEO and ultimately back into the atmosphere for burn-up. That something-or-another is a wide open question, with everything from a solar sail to a tether payload to boost the orbit up.
But today, nobody has the technology pieces put together to cleanly put ZombieSat in the trash. Maybe Intelsat and the other affected satellite operators, plus DARPA pitching in, can set up a X-Prize contest to demonstrate a working solution, with the winner successfully de-orbiting ZombieSat.
|
