The Chinese space mission Tianwen-2 has reached asteroid 2016HO3, analysis phase begins

In recent hours, two distinct missions have reached two different asteroids. The first is Hayabusa2 by JAXA, which briefly flew over asteroid Torifune, collecting new scientific data and a close-up image (before continuing its journey). The second mission is Tianwen-2 by CNSA, which has finally arrived at its destination, encountering asteroid 2016HO3 (also known as 469219 Kamo'oalewa).

After the Chang'e missions, China aims to bring back samples of regolith from an asteroid to Earth. This isn't a "new" mission considering that both JAXA and NASA have achieved this in the recent past, but it is the first time for CNSA and will allow for the acquisition of further independent technological and scientific capabilities. The challenge for Tianwen-2 will be even more complex, given that asteroid 2016HO3 is the smallest (about 20 meters in diameter) among those selected for sampling and rotates rapidly on its axis.

According to reports from CNSA, after about 400 days of travel (the mission was launched at the end of May 2025), covering approximately 1 billion kilometers, the spacecraft has finally reached asteroid 2016HO3, coming to a distance of 20 kilometers from the target and starting data acquisition operations. During the approach phase, about a month ago, the Tianwen-2 spacecraft captured an initial image of the asteroid and then corrected its trajectory while still 30,000 kilometers away. In about ten days, the distance was reduced to 2,000 kilometers.

Before sampling, scientists and engineers will collaborate to gather more information about the target asteroid to ensure the areas from which to collect material and how to properly approach the object's surface. To increase the chances of success, CNSA has planned three different sampling systems: one based on a robotic arm, one with brushes, and finally one with a system that mimics the movements of a hand/paw.

The spacecraft is also equipped with a variety of scientific instruments, including cameras, a visible and infrared spectrometer, an instrument for thermal analysis, radar, a magnetometer, and tools for analyzing charged and neutral particles.

The Tianwen-2 mission will not only target asteroid 2016HO3 but, after completing operations and delivering the capsule to Earth, will continue its journey to comet 311P, which is located in the main asteroid belt. As with other asteroid-related missions, studying 2016HO3 will provide additional information about the primordial Solar System, which will complement data from other missions with different objectives.