SpinLaunch

A U.S. space launch start-up has, for the first time, demonstrated a kinetic-based system that’s intended one day to put small spacecraft into orbit.  The SpinLaunch concept, which feels ripped right from the classic age of science fiction, is based around a vacuum-sealed centrifuge that spins an unpowered projectile at several times the speed of sound before releasing it, hurling it into the upper atmosphere, and ultimately into orbit.  In this way, the company, based in Long Beach, Calif., hopes to challenge traditional rockets for putting payloads into space.

The first test flight of a prototype -- a so-called suborbital accelerator -- took place at Spaceport America in New Mexico on October 22, but the company only announced the milestone yesterday.

The system uses a vacuum chamber within which a rotating arm brings a projectile up to very high speed without any drag penalty, before hurling it into the atmosphere "in less than a millisecond," according to the company, as a port opens for a fraction of a second to release the projectile.  A counterbalance spins in the opposite direction to prevent the system from becoming unbalanced.  The vacuum seal stays in place until the projectile breaks through a membrane at the top of the launch tube. 

-- Thomas Newdick and Tyler Rogoway, "Space Launch Start-Up Just Used A Giant Centrifuge To Fling A Projectile Into The Upper Atmosphere", thedrive.com, 10 November 2021