Tianwen-2, China’s first asteroid sample-return mission, has arrived at a distance of 20 kilometers from the near-Earth asteroid 2016HO3, according to the China National Space Administration (CNSA). Launched on May 29, 2025, the probe traveled approximately 1 billion kilometers over 400 days to reach the asteroid.
Approach and Navigation
During its approach, the probe acquired imagery and used optical navigation data to refine the asteroid’s ephemeris. This process reduced positional uncertainty from hundreds of kilometers to the kilometer scale.
Key trajectory milestones include:
- June 6, 2026: First detection of the asteroid.
- June 7, 2026: Entry into a coplanar trajectory at a distance of 30,000 kilometers.
- June 19, 2026: Approach to within 2,000 kilometers.
- July 1, 2026: Arrival at a distance of 20 kilometers from the asteroid.
Scientific Objectives
The mission’s primary scientific goals are to study the asteroid’s morphology, material composition, and internal structure. These observations are intended to prepare for subsequent sample collection.
Mission Background
Tianwen-2 is China’s first asteroid sample-return mission, with a planned decade-long expedition. The probe will collect samples from 2016HO3 before proceeding to explore the main-belt comet 311P.