"Best kept secret" was a phrase used about Theranos, too. They also received money from Kleiner Perkins and the DOD despite their process being easily evaluated as impossible by anyone with any experience in blood chemistry or its measurement. For conversation's sake, here's a dowsing rod used to detect bombs that is still killing people. Experts fall down sometimes. Often when they aren't asked. Or when they're asked one question and the charlatans say they answered a different one.

Let's look at some basic numbers. We'll use the ones on their own Wikipedia page which is 4800 km/h or 1333 m/s. They're trying for a "catapult" (centrifuge) three times the size of their proto, so 120ft in diameter. Newtonian physics says that our 200lb payload is experiencing 1,000 tons of force and approximately 10,000g. Separating blood into plasma, for comparison, takes 5 minutes at 3000g and we're gonna take an hour to spin this sucker up. 362 ksi turns the lead in your pencil to diamond. Build the proper anvil for this thing and you won't need to send anything into space to turn a profit.

That doesn't get us into orbit, though. That gets us spit out the end of the centrifuge where we go from vacuum to atmosphere and 10,000g to one (do you like how there's no deceleration there? No accommodation for that transition? 'cuz I do). We now need to boost our rocket to get us from 1333 m/s to 7500m/s. We're going to burn for a minute: v(f) = v(i) plus (a)(t) so (a) is 103 m/s^2. Never mind the fuckin' centrifuge we're going to burn at 10 1/2 g for a minute. A Sprint missile will do that (it'll do the shit out of that) but out here in the land of normal? A Falcon 9 is good for about 12m/s^2 (or 2 once you cook off gravity).

If our rocket weighs nothing but rocket fuel and we're trying to get a 200 kilo payload to LEO, we're now talking about 1400 kilos of solid rocket fuel, assuming the most efficient rocket fuel imaginable (thanks, omnicalculator). Our payload has been through some shit. So has our catapult. By our design we're ditching our counterweight at the same time as our payload; we've got 1600 kilos experiencing 10,000g. It's gonna cut loose at 1333 m/s. KE = 1/2 (m)(v)^2 so about 1400 megajoules. We aren't in kiloton yield range but just letting the fucking thing go is gonna let go of as much energy as blowing up a 600lb stack of TNT. You're going to have to do something with that. Water column, pressure canister, dunno.

Meanwhile our spinny arm is experiencing 311,000 kN of force. We'll build it out of kevlar because tensile strength is where we're at. Never mind any forces other than lateral; 898Mpa/m3 means we need a third of a meter square of kevlar fibers (pulling straight! not in a mat!) to make this work. Talkin' a lab-grown stalk of aramid 60cm in diameter and 120 feet long. Or, the equivalent structure, which is gonna be sumpin' else.

Let's take a step back. Suppose we skip the catapult entirely. We're going to boost at 10g because fuck you, that's why. Let's start from zero rather than 1300m/s. Tsiolkovsky equation says we're now looking at a 7500kg rocket; we're basically trading 10,000g of pain for 6 tons of first stage.

Now. Push that "centrifuge" out to, oh, 200 miles and suddenly you're at escape velocity having experienced a mere 18g.