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NASA plans filling stations in sky
- The filling stations NASA calls them propellant depots would refuel a spacecraft in orbit before it headed out to the Moon, an asteroid or eventually Mars. Currently, all of the fuel needed for a mission is carried up with the rocket, and the weight of the fuel limits the size of the spacecraft.
- Next month, engineers will meet at NASA headquarters in Washington to discuss how propellant depots could be used to reach farther into space
- Under the plan outlined, the propellant depot would be launched first, and then other rockets would carry fuel to the depot before a spacecraft arrived to fill up. That would increase the complexity for an asteroid mission 11 to 17 launchings instead of four but could get NASA astronauts to an asteroid by 2024
- The budget needed for the project from 2012 through 2030 would be $60 billion to $86 billion
- Critics say the expense of developing and operating the massive new rocket, in an era of tight federal budgets, would doom the project.
- Propellant depots carry risks, too. Fuels like liquid hydrogen and liquid oxygen must be kept at ultracold temperatures and, unless the depots were heavily insulated, would boil away over time. And transferring fuel in the weightlessness of space is not straightforward, though perhaps simply setting the depot and spacecraft into a slow spin would generate enough force to push the fuel into the spacecraft.
