Electric auxiliary power unit for Shuttle evolution
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Meyer, Doug↗
Engineering topics
Scott, Walter
Publications and source records attributed to Scott, Walter.
Orbiter Auxiliary Power Unit Flight Support Plan
This paper discussed the development of an integrated Orbiter Auxiliary Power Unit (APU) and Improved APU (IAPU) Flight Suuport Plan. The plan identifies hardware requirements for continued support of flight activities for the Space Shuttle Orbiter fleet. Each Orbiter vehicle has three APUs that provide power to the hydraulic system for flight control surface actuation, engine gimbaling, landing gear deployment, braking, and steering. The APUs contain hardware that has been found over the course of development and flight history to have operating time and on-vehicle exposure time limits. These APUs will be replaced by IAPUs with enhanced operating lives on a vehicle-by-vehicle basis during scheduled Orbiter modification periods. This Flight Support Plan is used by program management, engineering, logistics, contracts, and procurement groups to establish optimum use of available hardware and replacement quantities and delivery requirements for APUs until vehicle modifications and incorporation of IAPUs. Changes to the flight manifest and program delays are evaluated relative to their impact on hardware availability.
Guirl, Robert↗
Electric auxiliary power unit for Shuttle evolution
The Space Shuttle Orbiter currently uses three hydrazine fueled auxiliary power units (APUs) to provide hydraulic power for the vehicle aerodynamic surface controls, main engine thrust vector control, landing gear, steering, and brakes. Electric auxiliary power units have been proposed as possible replacements to the hydrazine auxiliary power units. Along with the potential advantages, this paper describes an Electric APU configuration and addresses the technical issues and risks associated with the subsystem components. Additionally, characteristics of an Electric APU compared to the existing APU and the direction of future study with respect to the Electric APU is suggested.
Meyer, Doug↗