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Core Stage TVC Systems Engineering Challenges in Reusing Heritage HardwareThe Space Launch System (SLS) Core Stage (CS) Thrust Vector Control (TVC) system is comprised of 8 mechanical feedback Shuttle heritage Type III TVC actuators and four RS-25 engines, each attached to a Shuttle heritage gimbal block/bearing. Two actuators are used to move each engine in two planes perpendicular to one another (i.e., pitch and yaw). The TVC system design leverages hardware from the Space Shuttle program as well as new hardware designed specifically for the Core Stage. The Space Shuttle heritage hardware directly reused on SLS includes the Orbiter TVC hydraulic servo-actuators (with two slight design modifications), the Orbiter hydraulic circulation pumps, the Orbiter gimbal block/bearing, and the Solid Rocket Booster hydraulic pumps. The Core Auxiliary Power Unit (CAPU) is derived from the Orbiter Auxiliary Power Unit (APU). The Orbiter and Solid Rocket Booster APU turbines are powered by hot gas produced by catalyzed hydrazine decomposition. On the SLS Core Stage, the CAPU turbine is spun using cold gas tapped-off from the RS-25 to CS liquid hydrogen autogenous pressurization line. While direct reuse or slight modification of existing hardware may seem to be a triple-win for a program in cost, schedule, and technical risk mitigation, those benefits can only be realized when its degree of application in a new system is carefully and thoughtfully managed. The heritage hardware reuse should be prescribed within the heritage design capability and reuse environments must lie within the envelope of heritage qualification testing. Despite the significant test and flight experience of the Shuttle heritage hardware components, successful integration with the newly designed CS TVC components and incorporation into the stage design proved to be a challenge which required re-qualification of the heritage hardware as well as thorough integrated testing to support flight certification. Examples of the challenges that were overcome include: re-qualifying heritage hardware to survive new shock and vibration environments, certifying performance of extensively modified heritage hardware, regenerating design insight due to lack of available heritage vendor data, showing compliance to modern structural design standards, translation of heritage requirements for analog avionics to modern digital avionics, and interfacing heritage mechanical hardware with newly designed avionics. This paper is the second installment in a seven-paper series surveying the design, engineering, test validation, and flight performance of the Core Stage Thrust Vector Control system. This paper will discuss several engineering challenges encountered during the development process for SLS CS TVC and how they were successfully overcome to reach flight readiness.
Document ID
20230001017
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
Blake Stuart
(Marshall Space Flight Center Redstone Arsenal, Alabama, United States)
John Wall
(McLaurin Aerospace Dallas, Texas, United States)
Jeb Orr
(McLaurin Aerospace)
Jesse McEnulty
(Marshall Space Flight Center Redstone Arsenal, Alabama, United States)
Pete Pektas
(Jacobs (United States) Dallas, Texas, United States)
Date Acquired
January 20, 2023
Subject Category
Launch Vehicles and Launch Operations
Report/Patent Number
AAS 23-154
Meeting Information
Meeting: 45th Annual AAS Guidance, Navigation and Control (GN&C) Conference
Location: Breckenridge, CO
Country: US
Start Date: February 2, 2023
End Date: February 8, 2023
Sponsors: American Astronautical Society
Funding Number(s)
CONTRACT_GRANT: 80MSFC18C0011
Distribution Limits
Public
Copyright
Public Use Permitted.
Technical Review
Single Expert
Keywords
Thrust Vector Control
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