August 1, 2013.
Preservation of Biosignature Molecules in Potential Sample Return Container of the Mars 2020 Mission
Kimberly Lykens1 and Fei Chen2
1Wittenberg University, Springfield, Ohio 45501 2Jet Propulsion Laboratory, Pasadena, California, 91109
One requirement for sustainable life on terrestrial planets includes the presence of organic polymers, compounds that are essential for major biological functions such as replication and catalysis. An identified goal of the Mars mission in the year 2020 is to implement a sample-return to identify and validate signs of life on Mars through the discovery of biosignature molecules in Martian core samples. Martian core samples recovered during a sample-return mission will likely remain in contact with a metal container for anywhere up to ten years; therefore, understanding how molecular evidence of life will interact with the potential metals over time is important in ensuring true data upon sample return. Three types of organic molecules, Adenosine triphosphate, amino acids, and bacterial endotoxins, were used to represent biosignature molecules. These organic molecules were recovered from separate coupons composed of the potential metals for the sample return container: titanium, stainless steel, and the unique shape-memory metal alloy of nickel titanium. Known concentrations of the organic molecules were individually placed on the three different metal coupons and corrosion tests using electrolysis on Mars simulate soil samples were imposed on the prepared metal coupons to replicate metal decay overtime. These organic molecules were recovered from the coupon surfaces and the appropriate assay procedure for each molecule was conducted to evaluate the preservation of biosignatures after the electrochemical corrosion of metals. The effectiveness of each metal in preserving molecular indicators of life will be evaluated and used in determining the material composition of the sample container. Choosing the most suitable metal for the container will ultimately ensure sample integrity and biosignature preservation for sample testing upon return.
Biochemistry | Bioinformatics | Biology | Biotechnology | Molecular Biology
Dr. Fei Chen
NASA Jet Propulsion Laboratory (JPL)
This material is based upon work supported by the S.D. Bechtel, Jr. Foundation and by the National Science Foundation under Grant No. 0952013 and Grant No. 0833353. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the S.D. Bechtel, Jr. Foundation or the National Science Foundation. This project has also been made possible with support of the National Marine Sanctuary Foundation. The STAR program is administered by the Cal Poly Center for Excellence in Science and Mathematics Education (CESaME) on behalf of the California State University (CSU).