Dr. Luz Marina Calle, Lead Scientist and Principal Investigator, Corrosion Technology Laboratory, Kennedy Space Center

Dr. Luz Marina Calle earned her Ph.D. in chemistry from Ohio University and shortly thereafter became a professor of chemistry at Randolph College in Virginia. In 1989, she was selected to participate in NASA’s Summer Faculty Fellowship program at the Kennedy Space Center (KSC). Her summer work at KSC continued for a decade while performing her duties as professor and chair of the chemistry department at Randoph College. In 2000, Dr. Calle joined NASA permanently. She now leads NASA’s Corrosion Technology Laboratory at KSC.

NASA Tech Briefs: Dr. Calle, you currently head up NASA’s Corrosion Technology Laboratory, which was formally established in 1985 at the Kennedy Space Center. Tell us about the Corrosion Technology Laboratory and the types of projects you typically get involved with.

Dr. Luz Marina Calle: NASA began corrosion studies at KSC in 1966 during the Gemini/Apollo Programs when KSC’s Beachside Atmospheric Exposure Test Site was established to evaluate coatings and maintenance procedures for the corrosion protection of carbon steel. The facility is still being used today and is available to customers outside NASA.

In 1985 we introduced other techniques to look at corrosion in addition to long-term atmospheric exposure. We introduced the use of electrochemical techniques that allow us to look at corrosion on a faster scale. In 2000, we became NASA’s Corrosion Technology Laboratory where, in addition to corrosion testing, we incorporated an applied research capability to develop technologies that provide a solution to NASA’s corrosion-related problems. These technologies will also have applications outside NASA and will be made available for commercialization.

The types of projects that we typically get involved with depend on the needs of our customers. We find ourselves in the position where, very often, our customers don’t even know that the problems they’re having are corrosion-related. A recent example involved the corrosion failure of the stainless steel that was selected to fabricate flex hoses and tubing. These materials were selected for their high resistance to corrosion, but failed at the launch pad and we had to find alternate materials. Another problem occurs when the commercial production of coatings that we use for corrosion protection is discontinued. This usually happens in response to stricter environmental regulations. So we’ll get a call asking, “What do we do now?”

We’re working on a project right now that’s aimed at identifying a corrosion protection coating for flexible hoses that carry fluids under cryogenic conditions. It’s a challenging project because we have unique conditions here and it’s not easy to identify something that is commercially available off the shelf. As a result, we are developing “smart coatings” for corrosion detection and protection, but I can tell you more about that later.

Basically, we support NASA’s KSC mission of launching in one of the most corrosive environments in the world.

NTB: Not only is the environment corrosive, but the high heat levels and acids generated during a space shuttle launch add to the problem. What is it about the exhaust gasses from the solid rocket boosters that makes them so corrosive?

Dr. Calle: The solid rocket boosters generate a very corrosive exhaust that consists mainly of alumina particles and about 70 tons of hydrochloric acid. There are no coatings that can withstand the direct impact of the highly corrosive exhaust from the solid rocket boosters. Coating selection for the corrosion protection of the pad is based on different zones classified in terms of solid rocket booster exhaust deposition: zone 1 receives direct rocket engine exhaust impingement, zone 2 includes surfaces that experience elevated temperatures and acid deposition, and zone 3 includes areas outside those of zones 1 and 2. This environment is very unique to NASA and is something that we will need to deal with for as long as we use solid rocket boosters to launch.