In this illustration of a Mars sample return mission concept, a robotic arm transfers samples of Martian rock and soil from a fetch rover onto a lander.

NASA and the European Space Agency are solidifying concepts for a Mars sample return mission after NASA's Mars 2020 rover collects rock and soil samples and stores them in sealed tubes on the planet's surface for potential future return to Earth.

NASA will deliver a Mars lander in the vicinity of Jezero Crater, where Mars 2020 will have collected and cached samples. The lander will carry a NASA rocket (the Mars Ascent Vehicle) along with ESA's Sample Fetch Rover that is roughly the size of NASA's Opportunity Mars rover. The fetch rover will gather the cached samples and carry them back to the lander for transfer to the ascent vehicle; additional samples could also be delivered directly by Mars 2020. The ascent vehicle will then launch from the surface and deploy a special container holding the samples into Mars orbit.

ESA will put a spacecraft in orbit around Mars before the ascent vehicle launches. This spacecraft will rendezvous with and capture the orbiting samples before returning them to Earth. NASA will provide the payload module for the orbiter.