Engineering PapersSearch

Engineering topics

Brown, Christina

Publications and source records attributed to Brown, Christina.

QuEST: Qualifying Environmentally Sustainable Technologies

TEERM focuses its validation efforts on technologies that have shown promise in laboratory testing, but lack testing under realistic or field environment. Mature technologies have advantages over those that are still in the developmental stage such as being more likely to be transitioned into a working environment. One way TEERM begins to evaluate the suitability of technologies is through Technology Readiness Levels (TRLs). TRLs are a systematic metric/measurement system that supports assessments of the maturity of a particular technology and the consistent comparison of maturity between different types of technology. TEERM generally works on demonstrating/validating alternatives that fall within TRLs 5-9. In instances where a mature technology does not exist for a particular Agency application, TEERM works with technology development groups and programs such as NASA's Innovative Partnerships Program (IPP). The IPP's purpose is to identify and document available technologies in light of NASA's needs, evaluate and prioritize those technologies, and reach out to find new partners. All TEERM projects involve multiple partners. Partnering reduces duplication of effort that otherwise might occur if individuals worked their problems alone. Partnering also helps reduce individual contributors' shares of the total cost of technology validation. Through collaboration and financial commitment from project stakeholders and third-party sources, it is possible to fully fund expensive demonstration/validation efforts.

Brown, Christina

Joint Lead-Free Solder Test Program for High Reliability Military and Space Applications

Current and future space and defense systems face potential risks from the continued use of tin-lead solder, including: compliance with current environmental regulations, concerns about potential environmental legislation banning lead-containing products, reduced mission readiness, and component obsolescence with lead surface finishes. For example, the United States Environmental Protection Agency (USEPA) has lowered the Toxic Chemical Release reporting threshold for lead to 100 pounds. Overseas, the Waste Electrical and Electronic Equipment (WEEE) and the Restriction on Hazardous Substances (RoHS) Dicctives in Europe and similar mandates in Japan have instilled concern that a legislative body will prohibit the use of lead in aerospace/military electronics soldering. Any potential banning of lead compounds could reduce the supplier base and adversely affect the readiness of missions led by the National Aeronautics and Space Administration (NASA) and the U.S. Department of Defense (DoD). Before considering lead-free electronics for system upgrades or future designs, however, it is important for the DoD and NASA to know whether lead-free solders can meet their systems' requirements. No single lead-free solder is likely to qualify for all defense and space applications. Therefore, it is important to validate alternative solders for discrete applications. As a result of the need for comprehensive test data on the reliability of lead-free solders, a partnership was formed between the DoD, NASA, and several original equipment manufactures (OEMs) to conduct solder-joint reliability (laboratory) testing of three lead-free solder alloys on newly manufactured and reworked circuit cards to generate performance data for high-reliability (IPC Class 3) applications.

Brown, Christina