China’s Chang’e 6 mission has brought back material from the farside of the Moon.

Sample return capsule in foreground with suited scientist approaching. Helicopter in background
The recovery of the Chang'e 6 sample return capsule.
CGTN

In a whirlwind, 53-day mission, China’s Chang’e 6 sample-return capsule reentered Earth’s atmosphere over the Siziwang Banner site in Inner Mongolia early Tuesday, carrying precious cargo: an estimated 2 kilograms (4.4 pounds) of material from the farside of the Moon.

"The Chang'e 6 returner landed accurately in the designated area . . . and operated normally, marking the complete success of the Chang'e 6 mission of the lunar exploration project and the world's first return of samples from the back of the Moon," the China National Space Agency announced in a recent press statement.

The bell-shape capsule touched down at around 6:07 Universal Time (2:07 p.m. China Standard Time) on June 25th, marking a new pinnacle in China's lunar sample-return missions. In 2019, Chang’e 4 landed on the farside landing and in late 2020, Chang’e 5 returned more than 1.7 kilograms (61 ounces) of material from the Mons Rümker site on the lunar nearside. Of that return, 77.7 grams have been distributed to 114 research teams worldwide.

Chang'e 5 samples
Samples from the Chang'e 5 mission. CNSA

Like Chang'e 5, Chang'e 6 was a quick, all-in-one expedition. Launched on May 3rd, the mission took five days to reach lunar orbit, touching down inside the Apollo Basin on the lunar farside and deploying a small rover as well as science experiments. It carried instruments for France, the European Space Agency, and Italy.

Chang'e 6
The rover deployed by Chang'e 6 snaps an image looking back at the lander. CNSA/CLEP

"We are very happy to come back to the Moon," says Philippe Baptiste (CNES, France). "Everything went pretty fine, and it will take a bit of time to get all of the data, and we really look forward to that."

The samples could provide insight into why the lunar farside is covered in craters while the nearside is instead smothered in ancient lava fields. Polar deposits are also of interest, as they may harbor water ice that could support future crewed expeditions.

Chang'e 6 on the lunar surface, as seen from orbit, is a small white shape against a vast field of craters
NASA’s Lunar Reconnaissance Orbiter snapped an image of Chang’e 6 on the lunar surface
NASA / LRO

After collecting samples from the surface as well as drilled locations just beneath, those bits of lunar regolith departed aboard an ascent vehicle on June 3rd, just 48 hours after Chang'e 6 had landed. That vehicle rendezvoused with an orbiter and transferred the samples before the sample-return capsule headed back to Earth with a departure burn on June 20th.

Although China was mainly silent on the mission's status until after Tuesday’s landing, amateur radio observers were able to track the incoming return. Several ground-based telescopes also followed Chang'e 6 as it approached, including Space Situational Awareness’ LEO telescopes based in Australia and the Virtual Telescope Project:

Chang'e 6 is a tiny dot amongst a field of stellar streaks
This time exposure shows Chang'e 6 on June 22nd as it was returning to Earth. Chang'e 6 is the tiny white dot (arrowed) at center.
Gianluca Masi / The Virtual Telescope Project

The capsule separated from the return vehicle at 13:20 UT when it was still 5,000 kilometers above the Atlantic Ocean, after which the return vehicle carried out an Earth-avoidance maneuver. At about 120 km altitude, moving about 11.2 kilometers per second (25,000 mph), the capsule performed one of several atmospheric skip maneuvers to bleed off speed and energy. China had tested this sort of high-speed return in 2014, with Chang’e 5-T1. Then, at 10 km altitude, the capsule opened its parachutes for deceleration and landing.

A short search by the ground team recovered the capsule, which was airlifted to the National Astronomical Observatories of China in Beijing for the opening and analysis of its contents. As with NASA’s OSIRIS-REX samples from asteroid 101955 Bennu, Chang’e 6’s lunar samples are pristine, and precautions must be taken to keep them that way during handling.

China’s Queqiao 2 orbiter, launched earlier this year to relay communications to and from Chang'e 6 from its vantage point at the Earth-Moon L2 Lagrange point, is expected to last 8 years. In addition to carrying a suite of instruments, including an ultraviolet camera and a radio experiment, Queqiao 2 can also cover the next few Chang’e missions.

The Chang’e 6 mission return is not only a milestone for China's space agency but caps a successful high point for the Chang’e program. Next up for China's lunar exploration is Chang’e 7, which will send a long-duration lunar lander and rover to Shackleton Crater in 2026.

Chalk up another first for China in space. It’ll be exciting to see what the samples can reveal about about the farside of the Moon.

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