NASA SBIR 2004 Solicitation


PROPOSAL NUMBER: 04 B1.03-9485
SUBTOPIC TITLE: Materials Science for In-Space Fabrication and Radiation Protection
PROPOSAL TITLE: Microwave Materials Processing for Space Applications

SMALL BUSINESS CONCERN (Name, E-mail, Mail Address, City/State/Zip, Phone)
RWBruce Associates Inc.
1594 Chickasaw Rd.
Arnold, MD 21012-2526

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Ralph W. Bruce
1594 Chickasaw Rd.
Arnold, MD 21012-2526

For a space-based fabrication effort to be effective, the weight, power requirements and footprint must be minimized. Because of the unique beam forming properties at the millimeter-wave frequency of 83 GHz, a compact and efficient materials heating system can be devised that can satisfy this need. To date, microwave and millimeter-wave based systems for materials processing have been developed only for terrestrially based manufacturing operations. The purpose of this SBIR proposal is to begin the development and to perform proof-of-concept tasks to demonstrate the feasibility of the microwave approach to space-based materials processing. Current conventional heating technology requires the heating of the complete volume of the furnace in order to achieve the temperatures necessary to perform a fabrication activity. This is typically a slow and energy intensive process. At 83 GHz, technology is available that can focus a multi-kilowatt beam into an area of 4 cm2 or smaller. Based upon the absorptive capability of the material, this may result in a temperature rise of several hundred degC/min which is confined to the immediate area of beam impingement. The result is one of putting the energy where it is needed to perform the task (e.g., ceramic joining, glass melting) more effectively.

NASA's need to construct radiation shielding, pressure vessels, storage containers, habitat structures, roadways, pathways and work surfaces, on the Moon or Mars, relies on In-Situ Resource Utilization (ISRU). NASA thus requires efficient technologies that will allow for in-space fabrication of needed structural and functional materials such as ceramics and ceramic composites. Millimeter-wave processing technology is an enabling one that should help reduce significantly the space requirements (i.e., footprint) needed to set-up a high-temperature materials processing facility.

The joining of high-purity ceramic materials is a continuing challenge. A recent project focused on the joining of precision ceramics to be used in an advanced accelerator design for the Department of Energy. This project demonstrated that millimeter-wave processing is advantageous to this type of application. Although this is a niche, it is indicative of its commercial potential. Also, the ability to join advanced ceramics in specific well-defined areas without significantly heating the surrounding material will find widespread use. Additionally, the ability to join at high temperatures while using low-temperature fixturing is a significant advancement of ceramic joining technology.