China’s Chang’e-6 Returns Samples from Lunar Farside

China’s Chang’e-6 sample return canister landed in Inner Mongolia today, bringing back samples from the far side of the Moon for the first time in history. The farside always faces away from Earth and nothing was known about it until the Space Age began in 1957 and Soviet and American spacecraft began sending back grainy images. Those images improved considerably over the decades and show that it’s very different from the nearside. Scientists are eager to learn why and now will be able to study actual samples.

Launched in May, Chang’e-6 set down in the Apollo Basin, part of the South Pole-Aitken Basin, on the lunar farside on June 1 Eastern Daylight Time (EDT). Named after China’s mythological goddess of the Moon, Chang’e-6 was equipped with a robotic arm to scoop up surface material and a drill to bore further down to collect a total of about 2 kilograms of regolith.

The sample return capsule lifted off two days later to rendezvous with the mother ship in lunar orbit while the lander remains on the surface. The mothership had to wait until June 20 for the right alignment of the Earth and Moon to begin the return trip. The capsule separated from the mothership and landed at Siziwang Banner in the Inner Mongolia Autonomous Region at 2:07 am EDT this morning (2:07 pm local time in China).

As usual, China’s government news agency Xinhua said little about the return in advance, but publicized it after the fact.

 

History in the making: China’s Chang’e-6 lunar probe has just returned to Earth! And that’s not all! It is carrying the first-ever samples collected from the far side of the moon. Xinhua correspondent takes you to the scene. pic.twitter.com/vEhaOaHKFI

— China Xinhua Sci-Tech (@XHscitech) June 25, 2024

The capsule is being brought to a laboratory in Beijing where it will be opened. Wang Qiong, deputy chief designer of the mission, told Xinhua they’ll separate the samples collected from the surface and those with the drill. Some will be stored permanently, some will be stored at a separate location as a backup in case of disaster, and the remainder will be distributed to scientists in China and elsewhere “in accordance with the lunar sample management regulations.”

This is China’s second lunar sample return mission. Chang’e-5 brought back samples from the nearside in 2020. Last year, NASA and China reached agreement enabling U.S. scientists to apply to obtain some of those samples after NASA certified to Congress that it was in conformance with the Wolf Amendment that restricts U.S.-Chinese space cooperation. First included in the 2011 NASA appropriations bill by former Congressman Frank Wolf (R-VA), Congress has repeated it in every NASA appropriations bill since.

Chang’e-5 brought back 1.73 kg (3.8 pounds) of lunar material, which adds to the 226 grams (0.5 pounds) returned by three Soviet probes in the early 1970s and 382 kg (842 pounds) brought back by the six Apollo crews that landed on the Moon between 1969 and 1972.  All of that is from the nearside. Chang’e-6 is the first from the farside.

Often misunderstood, the farside is no more “dark” than the nearside. The Moon is tidally locked to Earth so only one side faces us, but both sides experience 14 days of sunlight and 14 days of darkness.

This is China’s second farside lunar mission. Chang’e-4 and its Yutu-2 rover landed there in 2019 to study the surface, but could not bring back samples. Communicating with a spacecraft on the farside of the Moon requires a relay satellite, since there is no line of sight back to Earth. China launched the Queqiao-1 spacecraft to support Change’-4 and Queqiao-2 for Chang’e-6. Both are still operating.

China has long term plans for both robotic and human exploration of the Moon. Chinese officials say they expect to land taikonauts there by 2030.