Just like cryptocurrencies! One day, they could be green, so they count as green right now

I tried a bunch of other catapult sizes to get the g forces down, but even trying to get it down to 100gs, which would flatten humans and pulverize most hardware, made for impossibly large radii of spin.

If you want to send living creatures into space, which is after all the point!, no purely ballistic system is possible.

Escape velocity is 11.175k m / s and you need to achieve about half of this to make orbit, so let's make that our baseline.

5Gs perceived acceleration adds 4 * 9.80665 m/s to your speed per second (4 because 1 of the Gs is the Earth's gravitation...), or about 2.4 km/s/minute

So you'd have to undergo 5Gs of acceleration for 2.5 minutes, which requires a track almost 1000km long. At 10Gs, over a hundred kilometers.

I just estimated the last numbers because even a 1km vertical track is ridiculous to contemplate.

The only "cheap" way into space is a space elevator, which would require materials as yet uninvented, a whole new set of construction techniques, generations of work and trillions of dollars.