Title

How Clean is the Clean Room?

Author Info

Erik J. McFarland, STARFollow

Recommended Citation

January 1, 2014.

Abstract

In order to limit contamination and protect the integrity of search-for-life missions, spacecraft assembly clean rooms should be free of microorganisms to the extent that planetary protection guidelines require of the mission. This study monitored the bioburden of the clean room in which the Mars-destined InSight lander was being assembled. Samples of ten locations inside the clean room and one location outside were taken at monthly intervals, starting in March 2014 and scheduled to end in September 2014.

Bioburden was determined using qPCR and ATP analyses with qPCR targating 16S rRNA gene copy number and ATP targating metabolic activity of microbes. Samples were treated with propidium monoazide (PMA) to selectively distinguish between viable and non-viable cells prior to DNA extraction and qPCR. Analyses of total ATP, internal ATP, and ATP as measured by a handheld device were done.

Results from the first three samplings shows that the amount of both untreated and PMA treated DNA decreased significantly between the first sampling (3/21/2014) and the second sampling (5/13/2014), possibly as a result of increased assembly activity and rigorous cleaning practices.

Results of the ATP analyses showed no significant changes in total ATP, but internal and handheld ATP decreased between the second and third samplings.

The preliminary results indicate that the bioburden of the clean room changes inversely as a result of assembly activity and cleaning efforts. The clean room will continue to be monitored through an additional three months.

Disciplines

Environmental Microbiology and Microbial Ecology

Mentor

Dr. Parag Vaishampayan

Lab site

NASA Jet Propulsion Laboratory (JPL)

Funding Acknowledgement

This material is based upon work supported by the S.D. Bechtel, Jr. Foundation and by the National Science Foundation under Grant No. 0952013. 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).