NASA’s Perseverance rover has dropped the last of 10 sample tubes onto the surface of Mars, thereby completing humanity’s “first sample depot on another world.” The rover began depositing titanium tubes containing samples of rock and dust six weeks ago as part of the Mars sample return mission to collect Martian material and deliver it to Earth for further study.
Perseverance landed on Mars in February 2021, touching down inside a 28-mile-wide bowl known as Jezero Crater with a core mission to look for signs of ancient microbial life and gather samples of the Martian environment. Scientists believe that, billions of years ago, Jezero Crater may have contained a river that flowed into a vast lake, which could have provided the necessary environment to support microbial life.
The rover is currently carrying 17 primary samples, which the space agency hopes can eventually be delivered to a sample return lander and delivered back to Earth. The freshly completed sample depot — located in the Three Forks region of the Jezero Crater — will serve as a backup cache in case Perseverance is unable to deliver its onboard samples. The location of each tube has been carefully mapped so that they can be found and collected by two Ingenuity-like helicopters, even if covered with dust.
While the table has been set at Three Forks, Perseverance is reportedly still in good condition and will now undertake an extended mission to explore the nearby Delta Top territory. The Delta Top campaign is expected to last around eight months and will investigate rocks and sediment that appear to have been carried into the Jezero Crater by an ancient river.
The focus of the main mission now turns to the future reclamation of the Martian samples. Defense contractor Lockheed Martin was entrusted with building the Mars Ascent Vehicle (MAV) last year, which is required to lift off from the Red Planet’s surface — making it the first rocket to ever launch from another planet if successful — and pass the collected samples to a spacecraft being built by the European Space Agency, which will subsequently deliver the precious cargo into the hands of eager scientists back on Earth.
NASA currently estimates that the sample retrieval lander will land by 2028 at the earliest and that the collected samples won’t arrive on Earth until at least 2033.
That is, obviously, far easier said than done. The Mars sample return mission represents over a decade of work and requires numerous incredibly complex steps to succeed, some of which have never previously been attempted — such as landing a rocket on Mars that’s capable of taking off again. If the teams behind the mission can successfully pull off these herculean efforts, however, we will be closer than we’ve ever been to knowing if life has existed beyond our Earth.