NASA details totally doable, not science fiction plan for sending Mars rocks to Earth

So crazy, it just might work

A sample depot will be set up on Mars for NASA's Perseverance rover to stash Martian rock and gas specimens ahead of a lander arriving to return the material to Earth sometime in the 2030s ... hopefully.

Perseverance, sent to the Red Planet to hunt for signs of ancient microbial life, has been roaming the Jezero Crater and exploring its nooks and crannies since it landed in February 2021. The robotic geologist on wheels is equipped with various instruments to analyze and drill Martian rock samples that seem particularly interesting. The material is collected in sample tubes and stored onboard.

Perseverance has covered 8.2 miles across Mars, collecting 14 rock samples and one atmospheric sample. Now it's time to set down some of those tubes on Mars.

Although the rover hasn't finished its science campaigns yet, officials at NASA and the European Space Agency (ESA) are already plotting how to bring the Martian material back to Earth for further study. They plan to set up a depot, of sorts, at Three Forks, a flat area at the base of an ancient river delta in the crater that's suitable for a lander.

At every point Perseverance has sampled, the rover has made sure to collect two of each specimen. One set of samples will be dropped at the depot point, and the other set of samples will remain on the rover. When the lander arrives from Earth at Three Forks, the rover will drive up to its new friend, and a robotic arm will retrieve the tubes from Perseverance and load them into the lander. Separately, drones from the lander will take off and collect tubes from the depot. Thus, the depot will effectively act as a backup source of specimens in case the rover unloading goes wrong.

If all goes well, the samples will return to Earth using a small rocket.

"Choosing the first depot on Mars makes this exploration campaign very real and tangible. Now we have a place to revisit with samples waiting for us there," David Parker, ESA's director of Human and Robotic Exploration, said in a statement on Friday.

"The first depot of Mars samples can be considered a major de-risking step for the Mars Sample Return Campaign," he added.

Jezero Crater is believed to be an old, dried-up lake bed. Perseverance has found igneous and sedimentary rock samples during its exploration so far, plus signs of past volcanic activity, and evidence there was liquid water on Mars at some point.

NASA and ESA are teaming up for the Mars Sample Return Program. An Earth Return Orbiter is expected to be launched in 2027, while a Sample Retrieval Lander and two helicopter drones will be sent to the surface of the planet a year later. These are the drones that will carry the samples from the depot to the lander. A robotic Sample Transfer Arm will load the tubes into a capsule.

The capsule will sit on a Mars Ascent Vehicle, a rocket designed to boost the container system into orbit to be retrieved by the Earth Return Orbiter, which will then make its way back home. The Martian samples are expected to arrive on Earth in 2033. 

"Never before has a scientifically curated collection of samples from another planet been collected and placed for return to Earth," said Thomas Zurbuchen, NASA's associate administrator for science.

"NASA and ESA have reviewed the proposed site and the Mars samples that will be deployed for this cache as soon as next month. When that first tube is positioned on the surface, it will be a historic moment in space exploration." ®