THE FORMALIZATION OF DUNKING ON SpinLaunch --- The Dribble kleinbl00: I'm now convinced the main chamber was indeed at partial pressure. Maybe like half an atmosphere or so. In the Clint Mansell soundtrack promotional vid, at 0:46 I can see some of the membrane get sucked back into the chamber faster than gravity alone would pull it downwards, but not fast enough to indicate a near-totally evacuated chamber. Any whooshing and whizzing audio was probably synthesized and added in post, I'm increasingly sure. Right, so I just did some high school math regarding a maximum apogee of "tens of thousands of feet" for a ballistic shot vertically. The upper limit, 100,000 ft., requires a release velocity of a little less than 800 m/s. Escape velocity in the absence of any atmosphere is ~11,000 m/s, so you'll need to go ehhhhhhhhh a little faster. However; good news, some of the requisite velocity is offset by the plan to put something resembling a rocket engine and its fuel up to 10k g's before lighting the fuse before the payload can fall back to Earth. Did you notice the verbiage used in the press release? Launched at "20% of the centrifuge's maximum power"? This is not really a system well-defined by its power consumption. It’s a question of release velocity and how much payload is second-stage rocket and fuel. I bet it takes a lot of power to spin anything up to a high speed in an almost-not-vacuum. v^2/r says that if you scale up the centrifuge by a factor of three, --- Juke Uh-oh --- C'mon n' Slam if You Wanna Jam The establishment rocket launch environment is pretty well-characterized. NASA has specific requirements for each launch vehicle, which are passed on to contractors. For example, mechanical engineers are given a set of vibration table testing requirements. There is no static loading requirement, only a sine sweep test to confirm and zero-in on the resonances predicted from modeling, and then a random noise test. Based on the 2,000-kg weight limit, the mass of "payload" dedicated to shielding the actual payload from introduction to a near-instantaneous shock, or damping the actual payload response from the “jerk” may be, like, almost all of the "payload". The secrets behind the stability of a missile going Mach whatever with a bomb inside of it are: 1) A gradual acceleration inside a gradually changing fluid environment (lessening atmospheric density as it goes up). 2) The direction of the axis of symmetry (where the nosecone points) is almost exactly parallel to the velocity vector, and any stabilizing spin is confined along this axis, the axis of the lowest rotational moment of inertia. 3) Everything.; Everything, including the bomb and all associated electronics inside the missile, was designed with the environment in mind. We can see for ourselves in these videos that 1) & 2) failed. For 3), I doubt that anyone who's ever made any comms, optical, EM-fields, or particle sensing instrumentation (or even spacecraft buses, whatever) could honestly tell you they could pull 10k g's static load with anything remotely similar to their current mechanical design. Solid-propellant rocket fuel? Good luck, ya got a lotta free energy floating around, hopefully it doesn’t localize into anything sparkable. — The Rebound But, OK. We might should think about payload design with a ~100 g static load (just, like, for starters) and a way wilder dynamic environment, primarily based on the shock. As Devac points out, there are potentially more realistic future applications of spin-launching in other environments, like on the moon. The entire concept isn't stupid, but SpinLaunch currently looks to me like either an intentional misrepresentation of the facts to investors or a very deep ignorance. Or a bit of both. Just my opinion.10k g's
ten thousand times one “jee"
10,000*9.8m/s^2 of static centripetal acceleration
Hopefully, for attitude control, the release is exactly instantaneous across the entire length of the payload
Hopefully, to avoid a disastrously high jerk response of the payload components, the release interval (Δt) is as large as possible