The Scientific Reason NASA Sanitizes Spacecrafts Before Going to Mars

    NASA has been known for its breakthroughs in space exploration, such as launching the first humans to the Moon or sending rovers to Mars. But, these difficult tasks do not come without hard work and preparation to leave both planets unharmed. With scientific facts and research, this article will discuss why organizations such as NASA sanitize their spacecraft before going to Mars and how they do it.


    One of the main purposes of the Mars 2020 mission is to look for hints of previous life on the planet, as stated by NASA. Another reason is to transport rocks and dust from Mars for testing purposes. Upon arrival on either planet, there may be a chance of contamination on both sides. Scientists don’t want to inadvertently relocate planet Earth’s lifeforms to Mars, for that may confuse the search for life on the red planet, as well as change life on Mars if there are any. They also don’t want to hurt lifeforms on Earth by bringing harmful microbes back from Mars. Extensive sterilization of every spacecraft that is approaching or even close to another planet is required to prevent the events above from happening. “Planetary protection” is what the process is often called. 


    Specific standards have been set by NASA for the sanitization of their spacecraft. “The entire flight system has an allocation of no more than five hundred thousand spores,” explained Kristina Scott, planetary protection engineer for the Mars 2020 mission, “This sounds like a lot, but it’s not a lot. It’s almost equivalent to less than what you would find on your camera lens on your smartphone.” There is still a chance of contamination even after extensive sterilization, stated NASA. The only acceptable chances for trips like this are less than one in ten thousand. A category of one to five is given to the mission, reliant on how much the spacecraft will interact with either a planet or moon. The Mars 2020 mission is listed to be Category 5, which is the highest. 


    You may be asking by now, how is the sterilization process done? Keeping a spacecraft sterile consists of multiple steps. The first is to put it together in a “clean room”, which is filled with periodically sanitized surfaces and filtered air. Secondly, workers are required to wear protective suits and gear to keep themselves from contaminating the spacecraft. Finally, 70% isopropyl wipes are used to sterilize the spacecraft. Vaporized hydrogen peroxide is occasionally used as well. NASA previously used heat to sterilize the vehicles but found it could damage the spacecraft. 


    These practices are prone to criticism, though. Alberto Fairen, a planetary scientist at Cornell University, has disagreed with sterilization, saying that before Earth microbes can spread, Mars’s harsh surface would kill them before they would have the chance. There have been complaints from NASA’s Jet Propulsion Laboratory, saying that the sanitization process is ambiguous and rather expensive. In addition, the only spacecraft to ever meet NASA’s standards was the Viking landers, which went to Mars back in the 1970s. Although sterilization standards and practices have been criticized, they will continue to remain in place for the future to come.