Saturn V Second Stage Hydraulic Engine Actuating System

Saturn V Second Stage Hydraulic Engine Actuating System (EAS) used as engineering test hardware, weighing 144 lbs and measuring 28Ë x 40Ë x 14.5ËÂ. It is a complex electro-hydraulic plumbing assembly featuring an Auxiliary Motor Pump, Accumulator Reservoir Manifold Assembly (ARMA), and associated piping and connection points. The ARMA and Auxiliary Pump Assembly bear NASA George C. Marshall Space Flight Center tags noting the contact number as "NAS 7-200," associating it with the second stage of the Saturn V rocket (S-II). The unit also has a Parker Aircraft Co. tag for the Accumulator-Reservoir-Manifold Assembly.

The Saturn V's engine actuation system was a 3500-psi closed hydraulic system that provided power and forces to gimbal the J-2 rocket engines. The ARMA panel assembly was mounted on the stage thrust structure, and includes the main system filters, ground hydraulic power disconnect couplings, and relief valves in addition to the accumulator and reservoir. Fluid was distributed throughout the system by flexible hose assemblies and rigid tubing.

The operation of the S-II Engine Actuation System is described in the manual prepared by North American Rockwell, 'Engineering Course on Saturn S-II Systems for NASA (SD 67-654), Volume 2: S-II Stage Propulsion and Mechanical Systems.' In part: 'After first-plane separation and after control switching is accomplished, the engine receives a start signal. After a predetermined period of chilldown, the engine start tank discharge valve opens. At this time, the oxidizer turbopump accelerates, thus accelerating the main hydraulic pump. When system pressure reaches approximately 1500 psi, the servoactuators unlock and start to position the engines in accordance with the command signal, which had been switched in. Shortly thereafter, the accumulator lockup valve solenoid is deenergized, unlocking the accumulator to provide the main source of power to gimbal the engine during the separation transient. At 4 to 5 seconds after separation, the main hydraulic pump starts replenishing the fluid in the accumulator in addition to supplying system demand. Power for all subsequent gimbaling during S-II stage boost is provided by the main pump, supplemented by the accumulator during peak demands.'

This piece will be crated and shipped from California; the buyer is responsible for all associated costs.