SLM Produced Hermetically Sealed Isolation Valve James Richard* Abstract   Marshall Space Flight Center (MSFC) has developed a valve concept to replace traditional pyrotechnicdriven isolation valves. This paper will describe the valve design and development process. The valve design uses a stem/wedge to support a disk inside the valve. That disk hermetically seals the pressurized  fluids. A release mechanism holds the stem/wedge and a large spring in place. When required to open, a  solenoid is energized and pulls the release mechanism allowing the spring to pull the stem/wedge away from the disk. Now the disk is unsupported and the pressure ruptures the disk allowing flow to the outlet of the valve. This paper will provide details of this design, describe the development testing, and show the results from the valve level tests performed. Also, a trade study is presented to show the advantages of  this design to a conventional pyrotechnic-based valve. Introduction National Aeronautics and Space Administration (NASA) spacecraft and commercial payloads are faced  with similar issues of isolation of toxic propellants, limited propellant or pressurant resources, precision oftimed events, reliability of operations, and/or limited budgets. Hermetically sealed valves that use pyrotechnics to rupture internal passages are the state of the art in achieving the isolation, resource, and timing objectives. However, handling issues associated with pyrotechnics, quality control issues requiring lot sampling of valves, and costs associated with the handling, access, and design of these devices has  made the state-of-the-art valves a costly and involved solution. This effort was to utilize the Selective  Laser Melting (SLM) technology to offer valve solutions that would reduce or eliminate the cost and handling disadvantages of the state-of-the-art valves, while maintaining the necessary sealing  requirements of the valves. Valve vendors have in the past endeavored to manufacture these valves, but the costs associated with the actuators, sealing elements, and other production costs kept this from becoming a reality.  NASA missions have had disconcerting experiences using the state-of-the-art pyrovalves. MSFC  generally used these valves for launch vehicles and larger payloads. Goddard Space Flight Center  (GSFC) uses these valves in their fleet of earth observation satellites. Others NASA centers have had issues using these devices for everything from deep space missions to manned vehicles. Each had different needs and concerns and each had concepts to resolve the issues. MSFC and GSFC teamed to provide a proposal to pool ideas and resources, and design a valve that could replace pyrovalves at  similar costs and equal or greater reliability. Discussion Generally, the approach was to combine the MSFC and GSFC application requirements into a single set of performance requirements that enveloped the needs of both centers’ missions, develop concepts for the valves, perform a trade study of various concepts based on the performance requirements, select a  single design, complete a detailed Design, Develop, Test, and Evaluation effort for that single concept,  and perform limited testing to demonstrate viability. *Marshall Space Flight Center, Huntsville, AL /g51/g85/g82/g70/g72/g72/g71/g76/g81/g74/g86/g3/g82/g73/g3/g87/g75/g72/g3/g23/g21/g81/g71/g3/g36/g72/g85/g82/g86/g83/g68/g70/g72/g3/g48/g72/g70/g75/g68/g81/g76/g86/g80/g86/g3/g54/g92/g80/g83/g82/g86/g76/g88/g80/g15/g3/g49/g36/g54/g36/g3/g42/g82/g71/g71/g68/g85 /g71/g3/g54/g83/g68/g70/g72/g3/g41/g79/g76/g74/g75/g87/g3/g38/g72/g81/g87/g72/g85/g15/g3/g48/g68/g92/g3/g20/g23/g16/g20/g25/g15/g3/g21/g19/g20/g23/g3 471