Conceptual design of the space station combustion module

The purpose of this paper is to describe the conceptual design of the Combustion Module for the Intemational Space Station Alpha (ISSA). This module is part of the Space Station Fluids/Combustion Facility (SS FCF) under development at the NASA Lewis Research Center. The Fluids/Combustion Facility is one of several science facilities which are being developed to support microgravity science investigations in the US Laboratory Module of the ISSA. The SS FCF will support a multitude of fluids and combustion science investigations over the lifetime of the ISSA and return state-of-the-art science data in a timely and efficient manner to the scientific communities. This will be accomplished through modularization of hardware, with planned, periodic upgrades; modularization of like scientific investigations that make use of common facility functions; and through the use of orbital replacement units (ORUs) for incorporation of new technology and new functionality. The SS FCF is scheduled to become operational on-orbit in 1999. The Combustion Module is presently scheduled for launch to orbit and integration with the Fluids/Combustion Facility in 1999. The objectives of this paper are to describe the history of the Combustion Module concept, the types of combustion science investigations which will be accommodated by the module, the hardware design heritage, the hardware concept, and the hardware breadboarding efforts currently Underway. "Copyright @ 1994 by the American Institute of Aeronauticsand Astronualics, Inc. No copyrightis asserted in the United States under Title 17, U.S. Code. The U.S. Government has a royalty-free license to exercise all rightsunder the copyright claimed herein for Government_ purposes. AIJother rights are resew'ed by the copyright owner." NASA Lewis Research Center (LeRC) received approval from NASA Headquarters to begin a definition study and conceptual design effort for a Modular Combustion Facility in June of 1987. The objective of the study was to assess the feasibility, effectiveness, and benefits to potential users of a modular, multi-user facilityfor performing combustion science and applications experiments aboard the Space Station Freedom 1. Facility class hardware has been considered as an alternative to experiment specific hardware for several reasons; 1) modular, multi-user facilities can provide resources or services to users which are non-standard to space station, 2) the modular approach allows for growth in capabilities over time, 3) common subsystems developed across facilities improve maintainability and minimize logistics requirements, 4) minimizing the individual investigators experiment hardware should reduce the individual experiment development time, and 5) the facility approach can minimize cost to the overall science discipline program while maintaining operational flexibility. A study team was formed with the purpose of accomplishing five tasks: 1) define requirements for a modular combustion facility (MCF), 2) develop design concepts, 3) perform trade studies on these design concepts, 4) develop a plan for future development, and 5) obtain independent assessment of the concept and plan. A facility project scientist from The LeRC Space Experiments Division (SED) combustion science group was chosen to work with the engineering team and to define science requirements for formulation of a concept. The process used to define the requirements started with a reference set of microgravity combustion science experiments. This set of reference experiments was an extrapolation of the (then) current microgravity combustion experiment program and was intended to represent a majority of the program with potential combustion experiments. This initial reference experiment list contained the following experiment types?-: 1. StabilizedGaseous Combustion 2. Freely Propagating Rames 3. Flaming and Smoldering Combustion in Low Velocity Flows 4. Effects of Extinguishants on Flaming and Smoldering Combustion 5. Pool Fires 6. Droplets Combustion 7. Metals Combustion There were other facilities being conceptualized as well for operation on the space station, such as a containerless processing facility, a fundamental science facility, a biotechnology facility, and a furnace facility. In September of 1988 this set of reference experiments allocated to be performed in the Modular Combustion Facility was evaluated by the Combustion Science Discipline Working Group (DWG) and NASA Headquarters, and deemed to have appropriate commonality and scientificsignificance to require a unique facility dedicated to microgravity combustion investigations. Specific experimental requirements were developed for each of the above listed experiment categories in the reference set. These experiment specific requirements were then used as the basis for the LeRC team to develop a conceptual design of a Space Station Freedom based Modular Combustion Facility. At this point in the effort, a Space Station Freedom Modular Combustion Facility Assessment Workshop was held at the Lewis Research Center. The purpose of that workshop was to obtain science and engineering assessments of the Modular Combustion Facility design and operational concepts as well as the selected microgravity combustion science requirements used to develop those concepts. II. Combustion Science Accommodations As a result of this workshop, the study team further developed the experiment specific requirements and the conceptual design of the MCF. The facility scientist continued to refine the science requirements and developed a Science Requirements Envelope Document (SRED). This document encompassed the science requirements by which the hardware concept was being developed and were specified so that individual experiment science requirements would most often fall within this envelope. The envelope included seven representative experiment requirements: