The system involves ferrying people from one point to another by transporting them through aluminium pods encased inside steel tubes at speeds in excess of 700 miles per hour. It may sound futuristic but the technology behind it is nothing new. Inside the tubes the pods are mounted on thin skis made of Inconel, an alloy developed by SpaceX that can withstand high pressure and heat. At the front of the pod are a pair of air jet inlets and the air taken in by these is compressed by an electric turbo compressor