Tianwen 2 spacecraft halfway to target asteroid

China's asteroid sampling spacecraft, Tianwen 2, has been on its interplanetary journey for more than four months, and while it has traveled over 43 million kilometers, its mission is far from complete.

Currently traveling on a transfer trajectory, the robotic probe is about 45 million km from its destination, a near-Earth asteroid called 2016 HO3, and is in good working condition, the China National Space Administration said in a news release on Wednesday.

The CNSA also released an image taken by the probe's monitor camera; a selfie of the spacecraft, proudly adorned with the Chinese flag, with Earth distant in the background.

The Tianwen 2 mission, which is China's first attempt to bring pristine asteroid samples back to Earth, was launched on May 29, when a Long March 3B rocket carrying the robotic probe departed from the Xichang Satellite Launch Center in Sichuan province.

The probe is to reach 2016 HO3, a small asteroid about 40 to 100 meters wide, in the summer of 2026. The Tianwen 2 will study the asteroid using a suite of 11 instruments, including cameras, spectrometers and radars, before deploying special devices to collect surface samples.

The asteroid, which is also known as 469219 Kamo'oalewa, orbits the sun and, therefore, is a constant companion of Earth. It is too distant to be considered a true satellite of Earth but is the best and most stable example of a quasi-satellite to date.

After the asteroid samples are collected, the probe will travel back into Earth's orbit and launch a capsule containing the precious materials to the ground.

The samples will be distributed among scientists who will examine their physical properties, chemical and mineralogical content, and isotopic composition. The data gathered will contribute to studies on the formation and evolution of asteroids and the early solar system.

However, delivering the samples to Earth will not be the end of the mission. The Tianwen 2 spacecraft will then enter the second phase of its journey, flying toward a main-belt comet called 311P to conduct a remote-sensing survey and transmit the data back to Earth for scientific research, according to the CNSA.

The mission is expected to yield groundbreaking discoveries and expand the understanding of Earth and small celestial bodies inside the solar system, scientists said.