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Report on Alternative Devices to Pyrotechnics on SpacecraftPyrotechnics accomplish many functions on today's spacecraft, possessing minimum volume/weight, providing instantaneous operation on demand, and requiring little input energy. However, functional shock, safety, and overall system cost issues, combined with emergence and availability of new technologies question their continued use on space missions. Upon request from the National Aeronautics and Space Administration's (NASA) Program Management Council (PMC), Langley Research Center (LaRC) conducted a survey to identify and evaluate state-of-the-art non-explosively actuated (NEA) alternatives to pyrotechnics, identify NEA devices planned for NASA use, and investigate potential interagency cooperative efforts. In this study, over 135 organizations were contacted, including NASA field centers, Department of Defense (DOD) and other government laboratories, universities, and American and European industrial sources resulting in further detailed discussions with over half, and 18 face-to-face briefings. Unlike their single use pyrotechnic predecessors, NEA mechanisms are typically reusable or refurbishable, allowing flight of actual tested units. NEAs surveyed include spool-based devices, thermal knife, Fast Acting Shockless Separation Nut (FASSN), paraffin actuators, and shape memory alloy (SMA) devices (e.g., Frangibolt). The electro-mechanical spool, paraffin actuator and thermal knife are mature, flight proven technologies, while SMA devices have a limited flight history. There is a relationship between shock, input energy requirements, and mechanism functioning rate. Some devices (e.g., Frangibolt and spool based mechanisms) produce significant levels of functional shock. Paraffin, thermal knife, and SMA devices can provide gentle, shock-free release but cannot perform critically timed, simultaneous functions. The FASSN flywheel-nut release device possesses significant potential for reducing functional shock while activating nearly instantaneously. Specific study recommendations include: (1) development of NEA standards, specifically in areas of material characterization, functioning rates, and test methods; (2) a systems level approach to assure successful NEA technology application; and (3) further investigations into user needs, along with industry/government system-level real spacecraft cost benefit trade studies to determine NEA application foci and performance requirements. Additional survey observations reveal an industry and government desire to establish partnerships to investigate remaining unknowns and formulate NEA standards, specifically those driven by SMAs. Finally, there is increased interest and need to investigate alternative devices for such functions as stage/shroud separation and high pressure valving. This paper summarizes results of the NASA-LaRC survey of pyrotechnic alternatives. State of-the-art devices with their associated weight and cost savings are presented. Additionally, a comparison of functional shock characteristics of several devices are shown, and potentially related technology developments are highlighted.
Document ID
19960054342
Acquisition Source
Langley Research Center
Document Type
Conference Paper
Authors
Lucy, M. H.
(NASA Langley Research Center Hampton, VA United States)
Hardy, R. C.
(NASA Langley Research Center Hampton, VA United States)
Kist, E. H., Jr.
(NASA Langley Research Center Hampton, VA United States)
Watson, J. J.
(NASA Langley Research Center Hampton, VA United States)
Wise, S. A.
(NASA Langley Research Center Hampton, VA United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1996
Subject Category
Propellants And Fuels
Report/Patent Number
NASA-TM-110470
NAS 1.15:110470
Meeting Information
Meeting: Annual AIAA/USU Conference on Small Satellites
Location: Logan, UT
Country: United States
Start Date: September 17, 1996
End Date: September 19, 1996
Accession Number
96N36516
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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