In 2008 QTI Military and Aerospace Sales Manager Jon Fishback answered a phone call from NASA’s Jet Propulsion Laboratory. The NASA engineer on the other end of the line had a problem: his team was working on the new Mars rover, Curiosity, and had discovered the motors in the rover wheels would not work as efficiently as they needed at extremely low temperatures. The team had theorized a solution, but to implement a correction they needed a way for the rover to accurately assess very low temperatures. The NASA engineer wondered if QTI would be able to build a thermistor which would accurately read temperatures, especially between -128°C and -144°C (-198°F and -227°F). Fishback did some research and learned while it was technically possible to build a thermistor able to read such low temperatures, those temperatures had not been fully performance characterized before at QTI. The QTI engineering team decided to step up to the challenge and provide a solution.
Since NASA discovered the rover’s problem quite late in the design stage, the specification for the thermistor had to be developed, parts built and tested quickly in order to meet the Program’s completion date. “We fit about nine or ten months worth of work into about five months,” recalled Fishback. “Because of the tight schedule NASA was on, we were working on specifications, building prototypes, testing parts, and working on production parts simultaneously.”
The project was very ambitious. The thermistor had to work flawlessly under very hostile conditions for the entire length of the rover’s mission. QTI engineers started with a military-specification part and worked with NASA to create, modify and improve upon a new part specification until it finally met the performance NASA needed. The final result was a custom, cutting-edge performance thermistor. Through working with NASA QTI gained valuable insight into the kinds of reliability demands placed on parts headed for space flight missions. Based on this insight, QTI collaborated with NASA to create the NASA Goddard Space Flight Center S-311-P-827 specification for an entire family of surface mount spaceflight thermistors, both Negative Temperature Coefficient (NTC) and Positive Temperature Coefficient (PTC).
“NASA’s team knew what the problem with the Curiosity’s wheel motors was, and they knew the solution to the problem, but they needed QTI’s technical help to make the solution a reality,” Fishback said. “This project was a perfect fit for our company because our High Reliability Products team is small and nimble enough to take on challenging projects. Our engineers are always looking for new boundaries to push.”