China’s Tianwen-2 spacecraft is continuing its scientific exploration of a near-Earth asteroid following a rendezvous with asteroid 2016 HO3 in July 2026, according to the China Aerospace Science and Technology Corporation (CASC).

The mission represents a major step in China’s planetary exploration programme, combining asteroid sample collection with a planned investigation of a distant comet. Launched on May 29, 2025, Tianwen-2 is designed to conduct a decade-long expedition that could provide new insights into the formation and evolution of the Solar System.

Exploring Near-Earth Asteroid 2016 HO3

One of Tianwen-2’s principal objectives is to collect samples from asteroid 2016 HO3, also known as Kamoʻoalewa. The object is a small near-Earth asteroid that follows an orbit resembling that of a quasi-satellite of Earth.

Despite its unusual orbital behaviour, Kamoʻoalewa is not a permanent natural satellite of our planet. Its proximity and orbital characteristics make it an interesting target for studying the composition and history of small bodies in the Solar System.

By examining the asteroid remotely and collecting material for return to Earth, scientists hope to obtain information about its mineral composition, physical structure and possible origins.

Laboratory analysis of returned samples could reveal details that are difficult to establish through remote observations alone. Researchers may also be able to investigate how space weathering and impacts have altered the asteroid’s surface over time.

Preparing for the Sample-Return Phase

Following its rendezvous with the asteroid, Tianwen-2 is carrying out scientific investigations while preparing for the next stages of the mission.

Sample-return operations present substantial technical challenges. The spacecraft must operate in a weak-gravity environment, approach the asteroid carefully and collect material without compromising the mission’s ability to return it safely to Earth.

The collected samples will need to be protected during the return journey and recovered for scientific examination. Their analysis could help researchers compare the asteroid with meteorites and other small bodies studied through previous space missions.

The spacecraft’s ongoing activities are therefore important for both its immediate scientific objectives and the later return of material to Earth.

A Second Destination: Comet 311P

Tianwen-2’s planned journey extends beyond asteroid sampling. The mission is also designed to explore 311P/PANSTARRS, an unusual object in the main asteroid belt that has displayed comet-like activity.

Located in the region between Mars and Jupiter, 311P provides an opportunity to investigate the relationship between asteroids and comets. Although these objects are often described as distinct categories, observations have revealed that some asteroids can release dust and display features resembling cometary activity.

Studying 311P could help scientists understand the physical processes responsible for such behaviour and the diversity of small bodies in the Solar System.

The spacecraft’s extended mission will require careful navigation and management of its resources over several years.

Why Asteroid Sample-Return Missions Matter

Asteroids preserve material dating back to the early stages of Solar System formation. Unlike larger planets, many small bodies have undergone relatively limited geological processing, making them valuable targets for investigating the conditions that existed billions of years ago.

Returned samples can help scientists study the distribution of minerals and organic compounds, investigate the history of water-bearing materials and test theories about how planetary building blocks formed.

Such research also improves understanding of the physical properties and orbital behaviour of near-Earth objects, contributing to broader planetary science.

A Long-Term Milestone for Chinese Space Exploration

Tianwen-2 builds on China’s expanding programme of robotic exploration beyond Earth. Its combination of asteroid sampling and a planned comet investigation makes it an ambitious mission requiring long-duration spacecraft operations and precise navigation.

The mission’s scientific value will ultimately depend on the successful collection and return of samples, the quality of observations obtained during its journey and the discoveries made through subsequent analysis.

As Tianwen-2 continues its expedition, scientists will be looking for new evidence about the origins of small Solar System bodies and the processes that shaped the planetary system in which Earth formed.