Corrosion on Mars: An Investigation of Corrosion under Relevant Simulated Martian Environments

The goal of this research is to develop a systematic approach to understand corrosion of spacecraft materials on Mars by conducting a literature search of available data relevant to corrosion in the Mars environment and by performing preliminary laboratory experiments under relevant simulated Martian conditions. This project was motivated by the new found evidence for the presence of transient liquid brines that coincided with the suggestion by a team of researchers that some structure degradation cannot be attributed to rock scratching and may be caused by corrosive interactions of brines with spacecraft materials. An extensive literature search on data relevant to Mars corrosion confirmed the need for further investigation of the effect of the Mars environment on the materials used for spacecraft and structures designed to support long-term surface operations on Mars. Simple preliminary experiments, designed to look at the interaction between AA7075-T73 aluminum alloy and the gases present in the Mars atmosphere, at 20 degree C and a pressure of 633 Pa, showed that there is a significant interaction between the small amount of oxygen present in the Mars gas and the alloy when there is a scratch that removes the protective aluminum oxide film. There are many other important components of the Mars environment that can affect this interaction such as: the photo-catalytic effect of radiation on the oxidizing species, and the effect of salts in Martian soil. These initial experimental results provide strong justification for further investigation of the corrosion mechanism of materials relevant to long-term surface operations in support of future human exploration missions on Mars.