Identification and Survival of Microbial Isolates Collected from the Viking Spacecraft Surfaces Subjected to Simulated Environmental Conditions of Mars and a Conceptualized Model for the Advancement of Connecting Stakeholders in Science, Technology, Engineering, and Mathematics (STEM) Education
Thesis (Ph.D., Environmental Science) -- University of Idaho, 2016 | Existing risk for potential contamination of celestial bodies via space exploration—in addition to the risk for returning potential extant life to Earth—prompted implementation of planetary protection policy for all outer space missions. Planetary protection helps to mitigate these risks and is comprised of an international treaty, international and national planetary protection policies, and numerous requirements that are implemented at the national level. Mars is of particular interest, since it may have regions that could potentially host microbial life. Contamination of Mars could alter its natural state and compromise any current or future life detection missions. Mars-bound spacecraft must comply with requirements pertaining to the microbial bioburden on their surfaces prior to launch. Consequently, the Viking spacecraft surfaces (NASA) were required to undergo a comprehensive microbial sampling prior to a terminal sterilization cycle and launch to enumerate the spacecraft bioburden. Approximately 1,300 microorganisms, constituting the Viking microbial archive, collected from the Viking surfaces in the late 1970s were tentatively identified, lyophilized, and stored for future studies.
This study was undertaken to begin to address whether microorganisms transported from Earth during space exploration pose a potential contamination risk to planetary protection efforts. The objectives of this study were (1) to identify the 1,300 isolates within the Viking microbial archive, (2) to determine which isolates might withstand simulated Martian surface conditions and if isolates could use energy sources potentially available on Mars or other celestial bodies, (3) to determine whether Viking isolates capable of tolerating 20% NaCl conditions can survive and grow in MgSO4 at various temperatures and pH levels, and (4) to construct a conceptualized model related to partnerships within P-20 science, technology, engineering, and mathematics (STEM) education in informal and formal spaces. To promote engagement in STEM disciplines amongst students in formal and informal spaces, a conceptualized model is presented for consideration by practitioners and researchers. In the United States, student interest and achievement in STEM education is lagging behind other nations. Increasing interest and achievement in STEM disciplines is imperative for a strong future workforce in STEM fields including those pertaining to space exploration and planetary protection.