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Understanding the Space Shuttle Main Engine Hydraulic Actuation System and Reviewing Its EvolutionThe complex engine start and thrust control requirements of the Space Shuttle Main Engine (SSME) require unique valve, actuator and control system hardware. The Hydraulic Actuation System (HAS) was designed, developed, and now operates to meet tight engine control requirement limits to assure safe, reliable and correct engine thrust at all times. The actuator is designed to be fail safe and fail operate in the areas where redundancy is important. The HAS has an additional pneumatic operating capability that insures a safe sequential closure of all actuators and propellant valves in the event of the loss of hydraulic system pressure or loss of electrical closed loop control of the actuator. The objective of this paper is to provide a complete description of the actuator s internal operating system, along with its interaction with all SSME system interfaces. Additionally the paper addresses the challenges, problems identified, and corrected, and lessons learned, during the course of the almost 35 years of engine operation.
Document ID
20100022059
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
McWade, Robert J.
(Pratt and Whitney Rocketdyne Canoga Park, CA, United States)
Minor, Robert B.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
McNutt, Leslie M.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 24, 2013
Publication Date
May 4, 2010
Subject Category
Spacecraft Propulsion And Power
Report/Patent Number
M10-0229
Meeting Information
Meeting: 57th JANNAF Joint Propulsion Meeting
Location: Colorado Springs, CO
Country: United States
Start Date: May 3, 2010
End Date: May 7, 2010
Sponsors: Department of the Navy, Department of the Army, NASA Headquarters, Department of the Air Force
Distribution Limits
Public
Copyright
Other

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