[tromp]

https://www.dailymail.co.uk/sciencetech/article-10186369/The... has some more info:

"A 10ft-long projectile was rapidly accelerated to thousands of miles an hour in a rotating arm before being released for launch 'in less than a millisecond'.

The first suborbital flight used about 20 per cent of the accelerator's full power capacity and reached a test altitude 'in the tens of thousands of feet,' Yaney said.

The vehicle used did not have a rocket engine onboard but SpinLaunch does plan to add one, as well as other internal systems, in future test flights. "