China schedules launch of Tianwen 2

China's first asteroid sample-return mission, Tianwen 2, is scheduled to be launched in the coming months from the Xichang Satellite Launch Center in Sichuan province, according to the China National Space Administration.

The agency said on Thursday evening that the robotic probe was transported to the spaceport earlier that day. It added that facilities at the launch center "are in good condition, and pre-launch preparations are underway as planned".

The mission has been scheduled to take place in the first half of the year, the agency said.

According to mission planners, Tianwen 2, the country's second interplanetary expedition, will target 2016 HO3, the smallest and closest quasi-satellite to Earth.

The basic plan is to use a large carrier rocket to send a probe comprising two parts — an orbiter and a reentry module — toward the asteroid.

After approaching 2016 HO3, the unmanned spacecraft will orbit the asteroid and then fly very close to it to use a mechanical arm to scoop dust from the surface.

Next, Tianwen 2 will fly back to Earth's orbit and release its reentry module, which will return to the ground with the samples. The orbiter will then travel toward a main-belt comet called 311P to continue its scientific exploration tasks.

So far, scientists have identified about 1 million asteroids in the solar system, with more than 20,000 traveling near Earth.

The 2016 HO3, also known as 469219 Kamo'oalewa, was first spotted in April 2016 by an asteroid survey telescope at the Haleakala Observatories in Hawaii.

The celestial body orbits the sun, making it a constant companion of Earth. Scientists believe that it contains clues to the solar system's early history such as its original composition and the process of its formation and evolution.

Meanwhile, the 311P is part of the main asteroid belt between Mars and Jupiter. Its physical composition is like those of comets, but its orbital characteristics resemble those of asteroids, the agency said.

Studying the comet will help researchers learn more about the composition, structure and evolution of small celestial bodies, thus leading to more knowledge about such objects in the solar system, it explained.

Tianwen missions, named after an ancient Chinese poem, cover China's interplanetary exploration endeavors.

Tianwen 1 was launched in July 2020, and it successfully touched down on Mars in May 2021.

The probe deployed a rover, named Zhurong, to explore the Red Planet.

Zhurong was the sixth rover on Mars, after five from the United States.

zhaolei@chinadaily.com.cn