SpinLaunch is a technology company currently researching and developing a "ground-based, electric powered kinetic launch system" for the purpose of launching "200 kilogram class satellites into low earth orbit", potentially bringing the cost of launch to under $2,500 per kilogram.

The approach is to use a mass accelerator to spin a payload to Mach 6 before releasing it into the atmosphere. The payload will rise to 72 kilometers before a chemical rocket stage takes over, completing the lift to low Earth orbit.

While SpinLaunch has attracted $80 million in investment from GV, Kleiner Perkins, among others, the engineering challenges are unprecedented. The mass accelerator must spin in vacuum to prevent catastrophic damage from air friction. The spinning tether must withstand 10,000 gravities of force across 45 feet. The payload must be release precisely. The launch tube must close nearly instantaneously to prevent loss of vacuum.

Some critics like Scott Manley and Thunderf00t are skeptical that this is possible at all, given physics and current material science. Other critics, like Real Engineering are more sanguine.