RGClark
Mathematician
- Joined
- Jan 27, 2010
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You don't need a $500 million-per-launch spaceplane that only goes to LEO to refuel satellites in GEO. You can do that with a conventional launcher.
RGClark's method of calculating prices to GEO is pretty bad, I think it would be better to start with the launch cost and the cost of the refueling bus, rather than an arbitrary number.
The price to GEO is about twice that to get to LEO. Since the price to LEO is in the range of $10,000/kg, the price to GEO is about $20,000/kg. Shuttle launch prices are more expensive though so I estimated it as $25,000/kg.
The estimate of a charge of $100,000 per kg of the refueling fuel to be delivered to satellites in GEO is actually less than a price that has been quoted by a company planning on doing such refueling missions. On that "Space Infrastructure Servicing" wikipedia page is given this ref. to an article on satellite servicing:
de Selding, Peter B. (2011-03-14). "Intelsat Signs Up for Satellite Refueling Service". Space News. Retrieved 2011-03-15. "if the MDA spacecraft performs as planned, Intelsat will be paying a total of some $200 million to MDA. This assumes that four or five satellites are given around 200 kilograms each of fuel. ... The maiden flight of the vehicle would be on an International Launch Services Proton rocket, industry officials said. One official said the MDA spacecraft, including its 2,000 kilograms of refueling propellant, is likely to weigh around 6,000 kilograms at launch."
http://www.spacenews.com/satellite_telecom/intelsat-signs-for-satellite-refueling-service.html
So for this company they are charging $200,000 per kg of the refueling fuel.
The advantage of the shuttle is that it can carry so much refueling fuel to LEO for the spacecraft that does go to GEO to do the refueling. So potentially you could make so much with each shuttle launch. The shuttle could even leave this refueling fuel in LEO as a propellant depot for the small refueling spacecraft that goes out to GEO. The shuttle itself would not need to go to GEO.
The Ariane 5 with its large payload capacity to LEO could also be used for this role to get large revenue per launch. The advantage of the shuttle though is that it could bring back that GEO-refueling spacecraft for servicing.
It also has the advantage that it could also bring back the satellites themselves for servicing. It would have to be the large expensive satellites for which this would be worthwhile. Some of these GEO satellites cost hundreds of millions of dollars so this is conceivable. Some large defense satellites are also reported to cost over a billion dollars.
Again the shuttle itself would not need to get to GEO. It could use a small spacecraft to go out to GEO to attach to the satellites and use the spacecrafts thrusters and propellant to bring the satellites back to LEO to be captured by the shuttle.
BTW, it might be possible for the shuttle itself to reach GEO if you filled the entire payload bay with propellant, either with LH2/LOX or the hypergolics used with the OMS engines. But I can't see any advantage of doing it that way compared to having a small spacecraft instead go out to GEO and bring the satellite back down to LEO for the shuttle.
If so, then since the delta-V for a trans lunar injection is close to that required to reach GEO, it might be possible for the shuttle to reach the Moon, doing a free return trajectory to get back to Earth.
Bob Clark