According to its inventors, rockets accelerated to several times the speed of sound in a vacuum cylinder can reduce the cost of spaceflight to a fraction of the cost. In recent years, there have been countless ideas on how to make rocket launches more economical, from reusable booster rockets to giant planes carrying space assets to the stratosphere, to futuristic space elevators. SpinLaunch has chosen a different solution, and it looks like their calculations will work.