Will I get a a refund for the time spent lauching a new satellite?

October 4, 2009 4:44 AM

What happens when the satellite my pay-tv satellite-dish is pointing at dies?

Like tens of thousands of people in my part of the world, I get my "cable" TV via a satellite dish on my roof, pointing at a geostationary satellite. By my understanding, satellites have a limited life-span - am I right in thinking that this is probably more relevant to orbital satellites that will eventually fall out of orbit? - but in any case, a stray rock might hit my Austar satellite and render it useless.

Will my cable company then devote itself visiting every subscriber and pointing their dish at a new satellite? Is there any precedent for this?

posted by Jimbob to technology (5 comments total)

Replacement satellites go in the same orbital slot. Geostationary satellites are in 2 degree orbital spacing, so the new one can sit in the same "window" as the old without moving the dish. The old one will not re-enter, 22,300 miles is too high for the orbit to naturally decay, and the don't carry enough fuel for a deorbit burn.
posted by Marky at 5:20 AM on October 4

Most similar precedent was when Galaxy IV failed back in 1998, and disrupted most U.S. pager service. The immediate fix was indeed to re-point the "several hundred thousand antennas" . Then they moved another satellite (Galaxy VI) to the same position, and then they launched a replacement eventually. A bit different though because with pagers the dishes were company-owned rather than customer-owned.

I imagine a similar outage in Australia would be handled the same way. Optus has a bunch of satellites in similar orbits that they could reallocate or move if there was a major failure like that. The same satellite that handles Austar also handles Foxtel and the Australian military so it would be a big deal if it went out.
posted by smackfu at 6:51 AM on October 4

By my understanding, satellites have a limited life-span - am I right in thinking that this is probably more relevant to orbital satellites that will eventually fall out of orbit?

There are various small forces that will perturb the orbit of satellites in geostationary orbit, so they have to use up some propellants occasionally to keep themselves on-station. Once the propellants have run out, the satellite starts to drift and becomes useless, so lifetime is limited by the propellant supply.

Although they're too high up for atmospheric drag to eventually bring them down, and as Marky notes, don't have nearly enough propellant to deorbit themselves, these days they are often moved to a graveyard orbit a few hundred km higher up when their propellant supply is almost gone. That's so the out-of-control dead satellite won't drift into an operational one, but it would also free up the same orbital slot for a replacement satellite.
posted by FishBike at 7:28 AM on October 4

Not only do replacement satellites go into the same orbital slot, there can be multiple birds (satellites) in the same slot if they are positioned correctly. According to Lyngsat, Austar uses the 156E orbital slot and there are two sats located there: Optus C1 and D3. This means that even if one bird fails, the other will deliver at least some programming. Also, there are at least two similarly-configured sats in neighboring orbital slots, so they could conceivably be moved if nothing else. Note that this has happened before with a provider using satellites in the same orbital area.
posted by fireoyster at 7:57 AM on October 4

When Bell in Canada changed Satellites their new one was in a different orbital slot. They sent out instructions on how to repoint the dish yourself and if you couldn't manage it they sent out a tech. The TV company wants to keep that $100 a month rolling in and it only takes a few minutes to repoint a dish. They didn't charge subscribers but I think they did offer a programming credit or limited free access to premium channels on the new dish if you repointed it yourself.
posted by Mitheral at 10:02 AM on October 4