Link: https://en.wikipedia.org/wiki/SpinLaunch

The technology uses a vacuum-sealed centrifuge to spin a rocket and then hurl it to space at up to 4,700 mph (7,500 km/h; 2.1 km/s). The rocket then ignites its engines at an altitude of roughly 200,000 ft (60 km) to reach orbital speed of 17,150 mph (27,600 km/h; 7.666 km/s) with a payload of up to 200kg. Peak acceleration would be approximately 10,000 g. If successful, the acceleration concept is projected to lower the cost of launches and to use much less power, with the price of a single space launch reduced by a factor of 20 to under US$500,000.