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| An artist’s rendering of Tianwen-2 in space, depicting the spacecraft en route to its target asteroid as part of China’s ambitious deep-space exploration mission. |
China is preparing to launch the Tianwen-2 mission in May 2025, marking a major step forward in the country’s deep-space exploration program. The mission will attempt to retrieve samples from a near-Earth asteroid before heading into deep space to study a distant comet, making it one of the most complex interplanetary missions ever attempted by the Chinese space program.
Tianwen-2, also known as ZhengHe, will launch aboard a Long March 3B rocket from the Xichang Satellite Launch Center. Its primary target is asteroid 469219 Kamoʻoalewa, a quasi-satellite of Earth that orbits the Sun in a trajectory that keeps it relatively close to our planet. The spacecraft is expected to rendezvous with the asteroid several months after launch.
Once in proximity to Kamoʻoalewa, Tianwen-2 will attempt to collect at least 100 grams of surface material. To achieve this, it will use two different sampling methods. The first is a touch-and-go technique similar to that used by NASA’s OSIRIS-REx and Japan’s Hayabusa2 missions. The second is an anchor-and-drill method, in which the spacecraft secures itself to the asteroid’s surface to drill and extract subsurface material. These combined approaches aim to increase the scientific value and diversity of the samples returned.
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| A conceptual illustration of Tianwen-2 on the surface of asteroid Kamoʻoalewa, showing the spacecraft deploying its sampling mechanism to collect material during its brief landing phase. |
After completing the sampling phase, the spacecraft will begin its return to Earth. The sample return capsule is expected to arrive around 2.5 years after the mission begins. Upon successful reentry and recovery, this will make China the third nation to return samples from an asteroid, following Japan and the United States.
Tianwen-2 will not end its mission with the sample return. After delivering the capsule to Earth, the spacecraft will use a gravity assist maneuver to redirect itself toward a new target: the main-belt comet 311P/PANSTARRS. Unlike typical comets that originate from the distant edges of the solar system, 311P/PANSTARRS orbits within the asteroid belt between Mars and Jupiter. It exhibits activity—such as the ejection of dust or gas—despite being located in a relatively warm region of the solar system. Studying this comet may provide valuable insights into the volatile components that still exist within the inner solar system.
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| A simple 3D model of China's Tianwen-2 spacecraft, illustrating its basic structure and configuration for the upcoming asteroid and comet exploration mission. |
The spacecraft is equipped with an array of scientific instruments to support both its asteroid and comet objectives. These include multispectral and color imaging systems, thermal emission spectrometers, magnetometers, and devices for in-situ analysis of surface composition. The mission is expected to last about 10 years in total, with a year-long observation phase planned once the spacecraft reaches the comet.
Tianwen-2 continues China’s rapid expansion in space exploration. It builds on the success of Tianwen-1, which reached Mars in 2021 and deployed the Zhurong rover to the Martian surface. While Tianwen-1 focused on planetary science, Tianwen-2 aims to address key questions about the origins and evolution of small bodies in the solar system, the formation of planets, and the delivery of water and organics to early Earth.
The mission is named after the famous Ming Dynasty explorer Zheng He, symbolizing China’s intent to venture farther into uncharted regions of the solar system. By combining asteroid sampling with extended comet exploration, Tianwen-2 is set to position China as a major player in international space science, particularly in the field of deep-space robotic missions.