Answer: Luna 16

Sample return missions are spacecraft missions focused on obtaining samples of extraterrestrial materials. By far the most famous sample return mission of all time was the first sample return mission humanity ever engaged in: the Apollo 11 mission in 1969. Not only did we put men on the moon, but they brought back approximately 49 pounds of it with them.

While putting humans on the moon and retrieving a sample is a remarkable accomplishment, remarkable in its own right is the achievement of the Luna 16 space mission. Luna 16 was an unmanned space mission in the Soviet Luna program. What is remarkable about Luna 16 is that it was the first time a fully autonomous space launch had successfully gathered and returned an extraterrestrial sample—the Soviets fired a robotic probe into space and that probe returned part of the moon without any further intervention. Launched in September of 1970, the Luna 16 spacecraft orbited the moon, studied lunar gravity, landed on the surface, gathered a sample, and then blasted off towards Earth, ultimately returning a 101-gram (3.6 oz) sample of lunar soil (while the lower stage remained on the lunar surface and continued transmission of lunar temperature and radiation data).

In addition to being the first fully autonomous spacecraft to return an extraterrestrial sample (and the third successful sample return mission ever, following Apollo 11 and Apollo 12), Luna 16 was the first successful sample return mission performed by the Soviet Union. It was also the indirect source of the only private ownership of a lunar sample during the 20th century—in 1993, a sample from the Luna 16 mission was sold at a Sotheby’s auction for $442,500.

Other notable sample return missions include NASA’s Stardust spacecraft which, upon returning to Earth in January 2006, was the first spacecraft to return a comet sample in the form of debris from the tail of Comet Wild 2. In June 2010, the Japan Aerospace Exploration Agency (JAXA) reported that their Hayabusa probe returned a pristine sample of S-type Asteroid 25143 Itokawa.