NASA and ESA agree on next steps to return Mars samples to Earth

The next step in the unprecedented campaign to return scientifically selected samples from Mars took place on October 19 with a formal agreement between NASA and partner ESA (European Space Agency). The two agencies will proceed to create a tube sample repository on Mars. The sample repository or cache will be located at “Three Forks”, an area located near the base of an ancient river delta in Jezero Crater.

This crypt will contain samples of carefully selected rocks on the Martian surface – samples that can help tell the story of Jezero Crater and how Mars evolved, and may even contain signs of ancient life. Scientists believe that core samples from the fine-grained sedimentary rocks of the delta – deposited in a lake billions of years ago – are the most likely to contain indicators of whether microbial life existed when the Martian climate was very different from what it’s today

“Never before has a scientifically curated collection of samples been collected from another planet and placed for return to Earth,” said Thomas Zurbuchen, associate administrator for science at NASA headquarters in Washington. “NASA and ESA have been reviewing the proposed site and the Martian samples that will be developed for this cache as soon as next month. When this first tube is placed on the surface, it will be a historic moment in space exploration.”

The sample cache—a duplicate set of the collection that Perseverance will maintain—is one part of a robust plan to ensure mission success. The Perseverance rover will be the primary means of transporting the samples collected to the Mars launch vehicle as part of the campaign. The Three Forks warehouse will serve as a backup, housing the duplicate set.

“Selecting the first repository on Mars makes this exploration campaign very real and tangible. Now we have a place to revisit with samples waiting for us there,” said David Parker, director of ESA’s Human and Robotic Exploration division. “That we can implement this plan so early in the campaign is a testament to the ability of the international team of engineers and scientists working on the persistence and return of samples to Mars. The first Mars sample repository can be considered an important de-risking step for the Mars sample return campaign.”

The first step of the campaign is already underway. Since Perseverance landed in Jezero Crater on February 18, 2021, the rover has explored 8.2 miles (13.2 kilometers) of the Martian surface and collected 14 rock core samples during its first two science missions .

During its first science expedition, the rover explored the crater floor – a former lake bed – finding igneous rock, which forms deep underground from magma or during volcanic activity on the surface. The second scientific expedition has been highlighted by the investigation of sedimentary rocks, which formed when particles of various sizes settled in the once aquatic environment.

The rover has also collected an atmospheric sample and three control tubes. The control tubes contain material that helps identify possible terrestrial contamination in the tubes that may have come from the rover during sampling operations.

“While a major mission milestone will have been reached once these tubes are down, that doesn’t mean Perseverance’s explorations or sample collection is over — not by a long shot,” said Perseverance project scientist Ken Farley of Caltech in Pasadena, California.

“Then we’ll head to the top of the delta in an area that looks geologically rich from satellite imagery, conducting scientific surveys and collecting more rock cores. Mars Sample Return will have a lot of great stuff to choose from.”

In another major milestone, the Mars Sample Return Program entered the preliminary design and technology integration phase, known as Phase B, on October 1. and other risk mitigation activities.