The Hyperloop is like a mass driver - magnetically accelerate a capsule in an evacuated tube. But it uses air bearings and linear induction motors, unlike other designs. Considering SpaceX's CEO Elon Musk came up with the idea, I expected that somewhere someone would talk about whether the system could be modified for launching cargo at some point.
The concept is to use a tube which has had 99.9% of the air pumped out of it. Capsules are sent down it which use pumps on their front ends to suck in the build-up of air that is created as the capsule travels down the tube at high speed, and send that air out their back ends, and also to 'skis', where it is used to form an air cushion between the capsule and the walls of the tube. Linear induction motors are used to accelerate the capsule. In that scheme, the rotor on the capsules are just hollow aluminum blades, constituting only 5% of the capsule's weight. The air cushion suspension system forms 25% of its weight.
Would suspending the capsule with air provide a net benefit to the design of mass driver orbital launch systems? Does it lower power requirements, maybe, or allow a simpler design overall? Would air suspension continue to work at supersonic speeds? Are there other relevant differences between the two systems that i've missed?
I'd appreciate any input on how to improve this question. It was suggested it is quite similar to the question 'Is non-evacuated tube maglev launch possible?', but that question is about magnetic levitation, and the key thing here is that the capsule is not magnetically levitated. That question in fact proposes a very different system.
