Tianwen-2 launches — China's first asteroid sample-return mission

At 1:31 a.m. local time on 29 May 2025, still 28 May in universal time, a Long March 3B climbed out of the mountain valleys around Xichang and threw a probe clear of Earth's gravity. Tianwen-2, the second mission in China's 'Questions to Heaven' planetary series after the Mars mission Tianwen-1, was leaving to chase one of the strangest objects in the sky: 469219 Kamoʻoalewa, a body just tens of metres across that loops through space as a quasi-satellite, shadowing Earth's orbit around the Sun for centuries.

Kamoʻoalewa, named from a Hawaiian creation chant, may not be an ordinary asteroid at all. Spectral studies suggest its surface resembles lunar rock, and researchers have proposed it is a fragment of the Moon itself, possibly blasted free by the impact that carved the young crater Giordano Bruno. If so, China's probe is flying out to retrieve a piece of the Moon that escaped, a sample that could be checked directly against Apollo and Chang'e rocks.

The plan is the most ambitious small-body campaign yet attempted. After rendezvousing with the asteroid about a year after launch, Tianwen-2 will map it with eleven instruments, then try to collect on the order of 100 grams of regolith, using the touch-and-go technique proven by Hayabusa2 and OSIRIS-REx and, for the first time anywhere, an anchor-and-attach method that drills the spacecraft onto the surface of the tumbling body.

The sample capsule is due back at Earth in late 2027, but the mothership's journey will only be half done: it will then slingshot onward for a years-long cruise to 311P/PANSTARRS, an active main-belt comet expected around 2035. By June 2026 the spacecraft had closed in on Kamoʻoalewa and begun its approach operations, putting China on the threshold of joining Japan and the United States as the only nations to bring asteroid material home.