As NASA plans launches to Mars, Europa, and beyond, the agency's Office of Planetary Protection ensures that the environments are shielded against contamination, especially bacteria and microbes from Earth. Dr. Catherine Conley oversees and audits the planetary protection strategies for NASA’s exploration missions.
NASA Tech Briefs: What is a planetary protection officer?
Dr. Catherine Conley: The planetary protection officer is responsible for ensuring that agency-level missions comply with outer-space treaty policies on forward and backward contamination. That is, if you’re looking for life on Mars, don’t bring Earth life with you. In addition, the highest priority for planetary protection is to ensure that samples returned from another location are not permitted to introduce biohazards to the environment of the Earth.
NTB: How can Earth impact other planets?
Dr. Conley: If you’re looking for any indications of life, you need to make sure that your spacecraft is not covered with Earth life to such an extent that your instruments cannot detect the faint signals of Mars life or Europa life. You need to make sure that your background limits are low enough that the signal is going to be visible.
NTB: How do you protect against contaminants that could be brought to other planets?
Dr. Conley: The best practices were developed on the Viking project. [The 1975 Viking mission sent two space probes to Mars.] The Viking spacecraft and the life-detection instruments were cleaned very carefully for the kinds of contamination that might interfere with the instruments. The entire spacecraft, after it was packaged up in its heat shield, was put in an additional bioshield and baked in an oven that reached temperatures of 110 °C for 50 hours. That treatment was specifically designed to kill all of the organisms that would be on the surfaces of the Viking spacecraft. That is the kind of preparation that will be needed to go to Mars.
NTB: What do you say to someone who considers the approach to be overly cautious?
Dr. Conley: What would you say to someone who was telling the sailor on Columbus’s ship who had malaria that he shouldn’t come to the New World and let the mosquitos bite him? Malaria today is a $5 billion-per-year impact on the economy in Central America. If we had stopped people coming in from Europe bringing malaria, that would not be an economic consequence today.
Yes, we want to explore, but we need to be careful. There are all kinds of examples of introducing organisms in a non-controlled way that we didn’t understand. But the damage that’s caused by that ignorance is something that we can control. The choice by the global community in the 1950s to set up something like Planetary Protection is really the first time in the history of humanity that we as a global civilization have made the choice to do something right — to do things carefully this time.
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