Intelsat To Start Refueling Satellites In Orbit 79
mangu writes "Intelsat has signed a contract with Canadian MDA to refuel satellites in geostationary orbit. The $280 million contract will buy half of the 2000kg fuel carried by the space servicing vehicle. Besides refueling aging satellites, the vehicle will also be able to tow failed satellites away from the geostationary orbit."
Galaxy 15 'failed satellite' (Score:4, Interesting)
Re:How much per gallon? (Score:2, Interesting)
Over $127,000 per lb. A gallon of fuel is about 6 lbs depending on what kind. It's not too far from $1 million/gallon. btw, the cost of orbital launch is about $10,000 per lb - these guys must be making a ton of profit. The stock price for MDA agrees [quotemedia.com].
Re:Why do they need fuel? (Score:5, Interesting)
Since the earth is "oblate", which means flattened at the poles, the orbit over the equator isn't stable, it slowly gets inclined at a rate of approximately one degree per year. So-called "north-south" maneuvers are needed to keep the orbit exactly over the equator.
There are also "east-west" maneuvers. The earth is not perfectly symmetrical, rock is denser at some parts than at others, that's why we have ocean and continents. Denser rock sinks, lighter rock floats. The asymmetric gravity field from this difference in density pulls the satellite away from its intended location.
Inclination correction uses about 90% of the fuel needed for station keeping. This means that often older satellites are used in "inclined orbit", when the owner stops doing north-south maneuvers and lifetime can be extended, with some degradation in the services, because the antennas need to track the daily excursion of the satellite north and south of the equator.
Finally, some fuel is needed for deorbit. In order to keep the geostationary orbit uncluttered, the last drops of fuel are used to send the satellite to a "graveyard" orbit, a few hundred kilometers higher up.