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“ In the lift-off configuration, the vehicle is aerodynamically stable. A proportional control system featuring a combination of jet vanes and aerodynamic tip control surfaces operated by hydraulic servo actuators is used to control the vehicle throughout the entire first-stage burning period. These controls operate in pairs for pitch and yaw control. The jet vanes provide the majority of the control force during the thrusting phase and the aerodynamic tip controls provide all the control force during the coasting phase following burnout of the first stage. ”

“ If there is a fifth stage, it is ignited immediately after fourth-stage nominal burnout time. For orbiters, the entire third stage with its hydrogen peroxide control system still operating coasts to the apogee of the ascent orbit, aligning itself to a programmed altitude for fourth-stage ignition. At this time the final stage is spun up, the fourth-stage ignites, and the third-stage motor is blast separated. If there is a fifth stage, it is ignited immediately after fourth-stage burnout. A typical four-stage nominal ascent trajectory is presented in the table below. ”

“ The first-stage rocket motor will be fired from the ground level. After its burnout, the first-stage motor will remain attached to the vehicle until an altitude of 130,0OO feet is reached. The coast to 130,000 feet is done to effectively cancel the aerodynamic instability of the remaining stages and to relieve heating loads that could be incurred by igniting the second stage at lower altitudes. The second stage is ignited by means of a programmer and the first stage is immediately blast-separated. ”