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NASA | Electric APU - Advanced Hydraulic Power System - Shuttle Upgrades

A Continuing Journey with NASA

(Shown: The EAPU Three Channel System)

Following the success of our Dual Hydraulic Control (DHC) prototype, NASA provided us with a 10x funding increase to build a full scale, triple redundant, Electric Auxiliary Power Unit (EAPU). The system was also called the Advanced Hydraulic Power System (AHPS), and the individual motor/pump drives were Electro-Hydraulic Drive Units (EHDU).

This system could move 90 gallons of hydraulic fluid a minute at 3000 PSI, or about 3 KW of power, enough to replace Hydrazine APU operations on the Space Shuttle.

Instead of using LabVIEW and custom PID controls, this time we used Honeywell PID control systems and much larger BPM Motors and larger variable displacement pumps, all feeding into a central hydraulic manifold.  We also created a dynamic load.  Controlled by joystick, NASA engineers could move the Thrust Vector Control of a nozzle in real-time using the EAPU (see images below!)

Of course, I'd set high expectations with the prior prototype, and this next stand kept our reputation going.  Dynamically adjustable charts and graphs could be setup for any channels, order, size, and scaling, and placed anywhere on the dual screens, and saved as a configuration to return all monitors and test screens to that same setup at any time.

After delivery, Brad Irlbeck, the Chief Space Shuttle Upgrades officer, knew we could run the Shuttle using the EAPU.  Now we just had to wait for the battery technologies to catch up.

Note: The presentation snapshots below are publicly available on NASA's website, here and here.

Click Images Below for Details

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