StarTram is just as audacious as its name implies. It boils down to building a maglev train to outer space. Here’s how it works: Magnetically-levitated spacecraft will be propelled inside a curved tube aimed skyward. All air will be evacuated from the tube in order to eliminate drag. Craft will exit the lengthy tube at a speed of 8.8 kilometers per second in order to escape Earth’s atmosphere. A generation-1 StarTram design intended to launch cargo vessels will feature a 81-mile tube built up the side of a mountain to reach a launch altitude of 12,0000 to 20,000 feet. The Andes Mountains of Chile or the White Sands Missile Range of southern New Mexico might be ideal locations. Powell estimates that spacecraft could be launched every hour, carrying upwards of seventy tons of cargo per launch at a cost of just $20 to $50 per kilogram. An even more ambitious generation-2 StarTram design capable of ferrying hundreds of thousands of space tourists each year will feature a tube track between 620 and 930 miles long (to give more time for acceleration to minimize g-forces), likely situated in remote regions of Canada or Antarctica, reaching heights of 70,000 feet – almost twice as high as the cruising altitude of most passenger planes – to avoid drag when vessels exit the tube. The final 150 or so miles of the track will be magnetically levitated using powerful superconducting cables. This awe-inspiring highwire act operates on the exact same physical principles used to levitate trains.