Gas stations in space are an idea whose time has come. Certainly in the near future, which will see frequent trips to the moon and back, it will make sense. Lunar missions have always carried a backup amount of fuel that in most cases has gone unused and is either left on the Moon or burned up during reentry. Now this contingency amount could just wait there in space until needed OR could be counted on as fuel in order to lessen the load (weight-wise) of the rocket which would help ease the cost.
At MIT, a team has come up with 2 cost efficient depot designs. One uses a basic drop-off or pick-up a pre-set amount. This would involve either a robotic arm to hand off the fuel can or the astronaut actually picking it up. The 2nd method is more involved as it is somewhat similar to siphoning gas from a tank. Either way it opens the door for the next level, a space cantina with a fuel depot attached.
Suggested location? Lagrange points – regions in space between the Earth, the Moon, and the Sun that maintain gravitational equilibrium. Basically something you leave in one of these spots will maintain these spots, keeping the same relative position with respect to the Earth and Moon.
As there are more and more missions up in the moons orbit – fuel will become necessary. Previously required was staying in the same orbit but before the astronauts stay on the Moon they will first be running 3-7 day missions that take them to the poles to find water or elsewhere. These deviations require more fuel.
The architecture of this depot would be quite simple and hopefully robust against political uncertainty. However there are other concerns. In the location that would be perfect there is a drawback. Fuel that is not kept at a cool enough temperature could boil off – a well-known phenomenon.
This whole plan came out of 2 classes at MIT – Satellite Engineering and Space System Engineering and both are taught by Hoffman.
While this sounds like a plan, I suspect that somewhere down the line we’re going to have Bigelow Aerospace BA330’s hanging around as a rest area and fill-up station.