"* > What happens to the rest of your spin system when your payload releases?* "I mean, it's anchored to the ground, right? I'm sure it takes a shock but it sh

"* > What happens to the rest of your spin system when your payload releases?* "I mean, it's anchored to the ground, right? I'm sure it takes a shock but it shouldn't be out of the realm of stresses we already deal with regularly." Consider having one arm on the rotational axis. While it is spinning up, the axle is under significant stress, with the mass of the arm plus the mass of the vehicle under significant centrifugal force (Scott Manley says 10,000G at peak loading), which is a hard problem in itself. When you release the vehicle, the vehicle mass portion of that force goes to zero effectively instantly. Not a mechanical engineer, but I would expect a certain amount of vibration. Or possibly rapid disassembly. It's better if you have two arms with the vehicle on one and an equivalent mass on the other---when you launch the vehicle, you drop the other mass in the opposite direction. (Which is quite a synchronization problem.) (But where does that mass go?)