China's Tianwen-2 Mission Targets Near-Earth Asteroid for Sample Return
China Aims for Asteroid Samples
The China National Space Administration has revealed detailed plans for Tianwen-2, an asteroid sample return mission scheduled to launch in May 2025. The spacecraft will travel to 469219 Kamoʻoalewa, a near-Earth asteroid approximately 40 to 100 meters in diameter that some scientists believe may be a fragment of the Moon.
CNSA chief Zhang Kejian outlined the mission profile at the International Astronautical Congress in Milan. The spacecraft will reach the asteroid in late 2025, spend approximately 12 months in proximity operations collecting surface samples and conducting spectral analysis, then begin the return journey to Earth with an expected landing in 2030.
Scientific Objectives
Kamoʻoalewa is of particular interest because its spectral characteristics resemble lunar silicates, suggesting it may have originated from a large impact on the Moon. If confirmed, the samples would provide insights into the Moon's geological history and the mechanics of impact ejection.
The mission will collect approximately 100 grams of surface material using a combination of a touch-and-go mechanism similar to Japan's Hayabusa2 and a small anchor-drill system for subsurface material. Patrick Michel, an asteroid scientist at the Côte d'Azur Observatory, called the dual collection approach "elegant and scientifically ambitious."
Extended Mission to Comet
After releasing the sample return capsule toward Earth, the Tianwen-2 spacecraft will use a gravity assist to redirect toward main-belt comet 311P/PanSTARRS. This extended phase would make Tianwen-2 the first mission to visit both an asteroid and an active comet.
The dual-target design reflects China's growing confidence in deep-space navigation. The Tianwen-1 Mars mission, which successfully landed a rover in 2021, demonstrated the long-range communication and autonomous navigation capabilities needed for the asteroid mission.
Space Race Context
Japan's JAXA returned asteroid samples with Hayabusa2 in 2020. NASA's OSIRIS-REx returned samples from asteroid Bennu in September 2023. China's entry into asteroid sample return marks a new phase in its space program, which has rapidly advanced from crewed orbital flights to lunar sample return with Chang'e 5 and now interplanetary missions.
The mission budget has not been publicly disclosed, but analysts at the Secure World Foundation estimate it at approximately $800 million, significantly less than NASA's OSIRIS-REx at $1.16 billion.
