TFA mentions "the company has future plans to add a rocket motor inside the projectile to provide for orbital flights," which seems like it could be the solution, since it would allow the projectile to raise its perigee by thrusting at apogee. However, it also mentions "the rocket component is not a necessity for putting an object into orbit"; am I misunderstanding something or is the article just blatantly wrong about that?
Additionally, if we don't ignore drag, this seems like a really difficult/inefficient way to get something into orbit. A traditional rocket increases its velocity as it ascends and the atmosphere gets thinner; the vast majority of velocity is gained after the rocket has exited the atmosphere completely. Since drag increases with the square of velocity, it is really important to keep the velocity low(ish) until there's less atmosphere to fight against. Whereas with a centrifuge launch, we have to deal with orbital velocities in the thickest part of the atmosphere (plus the the extra speed needed to make up for the massive amount we're going to lose to drag). This becomes an easier problem (but still a problem) if most of the orbital velocity is in fact coming from the rocket engine rather the centrifuge...but then this starts to sound a lot like the "launch a rocket from a balloon" idea that always seems to get shot down: https://space.stackexchange.com/a/1641/17612
I'm not an aerospsace engineer, so I'd love to know how I'm misunderstanding this, because I know people much smarter than me have thought through these things. (The more I read the article, the more I think perhaps the author doesn't realize there's a difference between "exit[ing] the atmosphere" and achieving orbit.)