Sample-return mission

A sample-return mission is a spacecraft mission to collect and return samples from an extraterrestrial location to Earth for analysis. Sample-return missions may bring back merely atoms and molecules or a deposit of complex compounds such as loose material and rocks. These samples may be obtained in a number of ways, such as soil and rock excavation or a collector array used for capturing particles of solar wind or cometary debris. Nonetheless, concerns have been raised that the return of such samples to planet Earth may endanger Earth itself.

To date, samples of Moon rock from Earth's Moon have been collected by robotic and crewed missions; the comet Wild 2 and the asteroids 25143 Itokawa, 162173 Ryugu, and 101955 Bennu have been visited by robotic spacecraft which returned samples to Earth; and samples of the solar wind have been returned by the robotic Genesis mission.

In addition to sample-return missions, samples from three identified non-terrestrial bodies have been collected by other means: samples from the Moon in the form of Lunar meteorites, samples from Mars in the form of Martian meteorites, and samples from Vesta in the form of HED meteorites.

On 22 November 2023, NASA was reported to have cut back on the Mars sample-return mission due to a possible shortage of funds.