China has successfully launched the Tianwen-2 space mission, which aims to return samples from asteroid 469219 Kamooaleva, also known as 2016 HO3, to Earth. The Tianwen-2 spacecraft was launched aboard a Long March 3B rocket from the Xichang Space Center in southwest China, the South China Morning Post reported.
"About 18 minutes after launch, the rocket placed the spacecraft into a transition orbit from Earth to asteroid 2016 HO3. The spacecraft's solar panels successfully deployed, indicating the complete success of the launch mission," the China National Space Administration said in a statement.
2016 HO3, an asteroid that scientists believe may be a piece of the moon, is only the spacecraft's first planned visit. Tianwen-2 is expected to collect samples from the surface and return them to Earth in late 2027 via a reentry capsule. If Tianwen-2 is successful, China will become the third country after the United States and Japan to return samples from an asteroid.
The spacecraft will then use Earth's gravity to maneuver and begin a seven-year journey to comet 311P/PANSTARRS in the solar system's asteroid belt, known for its ability to produce numerous dust tails. The mission aims to study the comet's orbit, shape, rotation, surface composition and dust activity.
At the same time, Tianwen-2's first mission will be challenging. China has already landed on the Moon, but as planetary scientist Dante Lauretta of the University of Arizona points out, the microgravity conditions will make a landing on 2016 HO3 more like a rendezvous and docking, requiring completely different engineering solutions.
Lauretta has experience returning samples from an asteroid: he led the team that studied samples from the asteroid Bennu, delivered to Earth in September 2023. According to him, Tianwen-2 should also ensure the safe collection and transportation of pristine material to Earth.
Lauretta also noted that the two-phase Tianwen-2 mission will have additional challenges due to the long-term operation of the spacecraft over many years. However, he believes that, unlike the Japanese and American missions, the Chinese program can provide new insights into the early history of Earth-Moon collisions and the evolution of the Moon.
Qian Yuqi, a planetary geologist at the University of Hong Kong, said he was most interested in the origin of the asteroid, and if 2016 HO3 is indeed a piece of the moon, he wondered where it came from. If it is an S-type asteroid, the second most common type in the solar system, then the mission could help understand the origin of this family and the formation of planets like Earth.
In the future, China plans to launch the Tianwen-3 mission, which, if successful, will deliver the first samples of Martian rocks to Earth by 2031. And around 2030, the Tianwen-4 mission will launch to explore the Jupiter system and fly by Uranus.
