I'm not convinced that Spin-Launch is anything but vapour-ware. At risk of sounding like an arm-chair engineer, the G-forces experienced by the payload during it's rotational-phase must be astronomical. Not to mention the aero and thermal loads of slamming into the thick lower atmosphere at a substantial fraction of orbital velocity. The aerospace startup industry is no stranger to dumb ideas getting inexplicably large amounts of start-up capital, so capital itself isn't a reliable measure of their engineering expertise.

We shall see though.

EDIT: g-force calculation in a centrifuge is velocity^2 / radius. A 1st stage probably needs at least 4 km/s. A 10 km radius centrifuge yields a gigantic 1600 gs at that speed. So they're either building a centrifuge the size of a medium sized city, or their stage 1 speed is so slow that why bother with the added engineering complexity of this portion? This is without even considering the thermal and aero problem that emerges with high-speed flight at sea-level upon exiting the centrifuge. I think I'd keep my wallet closed on this one if I was an investor. Is there something I'm missing somehow here?

I agree, it's hard to imagine a payload that could withstand the g-forces required to reach space through a centrifuge launch. I think what interests investors is that in the low likelihood they succeed, they could create an order-of-magnitude reduction in launch costs. Some investors seem to have decided that was worth the bet

This is like saying that in the low likelihood that someone succeeds in jumping across the Atlantic ocean in a single leap, they will bring about a revolution in distance jumping. But while I don't think we've seen the limits of human performance in athletics yet, jumping oceans is not happening soon. Neither is centrifuging space payloads into orbit, because the engineering problems are simply too many magnitudes beyond what modern materials can handle.

If I were generous, investors in this company are taking a bet on the team and hoping that an eventual pivot pays off. If I wanted to not be generous there is probably some joke about Theranos, uBeam and FOMO in there.