in the tub at a rate varying from 450 to 750 rpm to compensate for thrust imbalance when the clustered motors fired. The rate of spin was varied by a programmer so that it did not couple with the changing resonance frequency of the first stage during flight.

The upper-stage tub was visibly spun-up before launch. During first-stage flight, the vehicle was guided by a gyro-controlled autopilot controlling both air-vanes and jet vanes on the first stage by means of servos. Following a vertical launch from a simple steel table, the vehicle