Combustion Integrated Rack

Combustion Integrated Rack
NASA · Public domain · source
Name	Combustion Integrated Rack
Country	United States
Organization	NASA
Application	Microgravity combustion research
Launched	2008
Platform	International Space Station

Combustion Integrated Rack is a laboratory facility developed by NASA for the International Space Station to study combustion phenomena in microgravity. The rack enables experiments that would be impractical on Earth due to buoyancy-driven convection, providing controlled conditions for investigations relevant to aerospace engineering, materials science, fire safety and energy systems. It supports long-duration, repeatable tests and has contributed to collaborations among institutions including Glenn Research Center, Ames Research Center, and partner agencies.

Overview

The Combustion Integrated Rack was conceived under programs at Johnson Space Center and Marshall Space Flight Center to address outstanding questions in flame dynamics and soot formation that affect technologies from jet engine combustors to terrestrial power plant burners. Its development involved contractors such as Orbital Sciences Corporation and academic teams from Princeton University, Massachusetts Institute of Technology, and Stanford University. The rack integrates optics, fuel delivery, and diagnostics to enable experiments like the Flame Extinguishment Experiment and studies related to the Sooting Flames Investigation.

Design and Components

The rack's architecture includes a test chamber, optical diagnostics, gas handling, and a safety enclosure derived from standards used on Space Shuttle middeck experiments and facilities like the Microgravity Science Glovebox. Major components include a sealed combustion chamber, windows for laser diagnostics similar to systems on Hubble Space Telescope instrument bays, a fuel-delivery manifold analogous in complexity to propulsion test rigs at Jet Propulsion Laboratory, and video cameras modeled after assemblies used on STS-107. Electronics and data systems are compatible with the International Standard Payload Rack interfaces and connect to station resources via Columbus (ISS module) and Destiny (ISS module) data networks.

Operational Capabilities and Experiments

The rack supports premixed, diffusion, and droplet combustion experiments with precise control over parameters such as pressure, temperature, and oxidizer concentration. Experiment protocols have been designed in partnership with teams from Georgia Institute of Technology, University of Michigan, and California Institute of Technology to investigate phenomena observed in ground facilities including Sandia National Laboratories combustor rigs and Princeton Plasma Physics Laboratory testbeds. Diagnostics include schlieren and laser-induced incandescence systems used in studies by groups at University of California, Berkeley and University of Illinois Urbana-Champaign, enabling measurement of flame structure, extinction limits, and soot particle size distributions.

Safety Systems and Fire Detection

Safety systems in the rack incorporate redundant controls, active suppression strategies, and detection hardware comparable to designs used on Space Shuttle and Soyuz spacecraft. Fire detection leverages pressure, temperature, and optical sensors similar to those deployed by Johnson Space Center safety teams and standards from National Aeronautics and Space Act-driven protocols. Containment and venting designs draw on experiences from incidents cataloged by agencies such as National Transportation Safety Board and research at Oak Ridge National Laboratory for handling combustion byproducts. Automated interlocks interface with onboard controllers in modules like Harmony (ISS module) to ensure crew safety during experiments.

Ground and Flight Testing

Before deployment, the rack underwent qualification at facilities including White Sands Test Facility and vibration testing at Marshall Space Flight Center to meet flight acceptance criteria used in missions such as STS-100 and STS-115. Thermal vacuum testing mirrored approaches applied to Mars Pathfinder instrumentation, while integrated system tests engaged crews trained at Johnson Space Center and Yuri Gagarin Cosmonaut Training Center. Flight verification experiments built on heritage from earlier microgravity combustion studies flown on STS missions and drop-tower campaigns at facilities like the ZARM Drop Tower.

Deployment on the International Space Station

The rack was installed in a US laboratory module on the International Space Station during assembly and logistics operations coordinated with Expedition 17 and later expeditions. Crew procedures for operation and maintenance were developed by teams at NASA and European Space Agency, with cargo delivery via vehicles such as Space Shuttle and Progress (spacecraft). Routine experiment runs were supported by ground controllers at Houston (NASA center) and data analysis collaborations involved international partners including Canadian Space Agency and Japan Aerospace Exploration Agency.

Scientific Contributions and Key Results

Results from experiments in the rack have advanced understanding of flame stabilization, soot inception, and flame extinction mechanisms, influencing models used by researchers at Sandia National Laboratories, Lawrence Livermore National Laboratory, and Battelle Memorial Institute. Insights into droplet combustion informed spray-combustion models used in Rolls-Royce and General Electric engine design studies, while soot and radiative heat transfer findings impacted atmospheric chemistry research at National Oceanic and Atmospheric Administration and Lamont–Doherty Earth Observatory. Peer-reviewed publications by teams at Princeton University, MIT, and Caltech have cited rack data in analyses of microgravity combustion instabilities and in validating computational fluid dynamics codes developed at NASA Ames Research Center and Argonne National Laboratory.

Category:NASA hardware Category:International Space Station experiments