Perseverance Might Bring Live Martian Organisms to Earth. But Is It Safe?

But how exactly will they bring these samples back? And how will the space agency, in its own words, "protect Earth from Mars" in the unlikely event it brings back live Martian organisms? The incredibly complex operation will hopefully see the first of the samples return to Earth by the 2030s.

The Mars Sample Return mission unleashed a 'torrent of creativity'

In September, the Mars Perseverance rover scooped up its first sample, drilling 2 inches (6 cm) into the planet's surface to extract a rock core, one of several that will one day come back to Earth, possibly bringing with it ancient fossilized organisms that would prove life once existed on Mars. "Returning a sample from Mars has been a priority for the planetary science community since the 1980s, and the potential opportunity to finally realize this goal has unleashed a torrent of creativity," said Michael Meyer, lead scientist for NASA's Mars Exploration Program. 

As NASA JPL points out in its blog post, the Mars Sample Return operation is a multi-mission campaign designed to retrieve cores that will be collected by Perseverance over the next several years. The U.S. space agency sent its Perseverance rover to the red planet to collect samples before designing the spacecraft and machinery that would retrieve those samples. In a collaboration with "dozens of government agencies," NASA says it will develop multiple spacecraft and technologies — all currently in the concept phase — in "one of the most ambitious endeavors in spaceflight history."

What we know so far is that the main spacecraft concepts are being developed by NASA and the European Space Agency (ESA). They are designing autonomous systems that will launch a rocket to Mars. Once there, an autonomous robotic fetch rover will descend into the red planet's atmosphere where it will collect the samples, which will be left on specific coordinates by the Perseverance rover. That rover (shown in the image above and the video below) will transfer the samples back to its lander, which will launch back to the orbiter.

The sample-carrying orbiter will then return to Earth, where scientists will finally be able to analyze the rock samples. The orbiter will place the rock samples into an Earth-entry capsule that will likely work in a similar fashion to Japanese space agency JAXA's asteroid sample re-entry capsule, which dropped a capsule into our atmosphere for a ground retrieval team to collect.

Protecting the Perseverance sample and 'protecting Earth from Mars'

In a fascinating turn, aside from protecting the samples from any contamination on their journey back to Earth, the Mars Sample Return mission will also take measures to "protect Earth from Mars." In its blog post, NASA said "it is highly unlikely that NASA will bring back samples with living Martian organisms, based on decades of data from orbiters, landers, and rovers at Mars. Instead, scientists are hoping to find fossilized organic matter or other signs of ancient microbial life." Still, the U.S. space agency says that, despite "the low risk of bringing anything alive to Earth, an abundance of caution is driving NASA to take significant measures to ensure the Martian samples remain securely sealed throughout their journey."

This means that, as unlikely as it might be, NASA is prepared for the possibility of bringing back living alien organisms — most likely microbes, not xenomorphs — back from Mars. That's why NASA is working on a special brazing method, which involves melting a metal alloy into a liquid to glue metal together. This will safely seal the sample capsule for its return mission to Earth, preventing even the smallest particles from escaping. It will also allow the outside of the capsule to be sterilized without damaging its contents — living or otherwise.

"Among our biggest technical challenges right now is that inches away from metal that's melting at about 1,000°F (538°C), we have to keep these extraordinary Mars samples below the hottest temperature they might have experienced on Mars, which is about 86°F (30°C,)" said Brendan Feehan, the Goddard systems engineer working on the brazing system. "Initial results from the testing of our brazing solution have affirmed that we’re on the right path."

NASA and ESA hope that their first sample return mission will be able to launch to the red planet at some point before 2030, meaning the samples would likely return in the 2030s — as a point of reference, the Mars Perseverance rover took seven months to reach the red planet. When they do, it will allow the scientific community to analyze the samples and gain a renewed understanding of the history of our Solar System, and possibly, its capacity for harboring ancient alien life. Thankfully, they will do that with a technology focused on keeping life safe here on Earth.