China's Tianwen-2 Probe Continues Normal Operations En Route to Near-Earth Asteroid

Helsinki - Ekhbary News Agency

China's Tianwen-2 Probe Continues Normal Operations En Route to Near-Earth Asteroid

China's Tianwen-2 spacecraft is reportedly operating normally on its journey to the near-Earth asteroid 469219 Kamoʻoalewa, according to a rare official update from the China National Space Administration (CNSA). The mission aims to study, sample, and return material from the asteroid before heading to a comet.

The update, provided by Zhou Jishi of the CNSA's Lunar Exploration and Space Engineering Center on February 9th at the UNCOPUOS Scientific and Technical Subcommittee meeting in Vienna, Austria, stated that Tianwen-2 is "currently operating in orbit with normal performance." The spacecraft is currently on a heliocentric transfer trajectory, a path that orbits the sun.

Launched on May 28th of last year, Tianwen-2 embarked on its ambitious voyage to Kamoʻoalewa (also known by its provisional designation 2016 HO3). This near-Earth asteroid has garnered significant scientific interest due to uncertainties surrounding its origin. While classified as a near-Earth asteroid, recent studies have hypothesized that it may consist of material ejected from the Moon, potentially linking it to a young lunar crater. Conversely, other research suggests a more conventional origin in the main asteroid belt, followed by migration towards Earth. The samples collected by Tianwen-2 are expected to provide crucial data to resolve this scientific enigma.

While Zhou did not specify the exact arrival date at Kamoʻoalewa, the official schedule indicates that the spacecraft is slated to deliver collected samples back to Earth by "the end of November 2027." This timeline suggests that Tianwen-2 will reach the asteroid in the coming months, allowing ample time for the commencement of its study and sampling campaign. The mission involves detailed investigations of the rocky body from various altitudes.

The projected timeframe for Tianwen-2's return to Earth and sample delivery appears consistent with an unverified timeline that circulated on Chinese social media approximately one month prior to the spacecraft's launch. This unofficial timeline indicated an arrival at Kamoʻoalewa in early July 2026, with a departure from the asteroid in April 2027, and the reentry capsule landing on Earth by November 29, 2027. Intriguingly, this timeline also includes a projected arrival at comet 311P in January 2035.

Upon reaching the asteroid, Tianwen-2 will conduct proximity investigations at progressively lower altitudes, descending from 20 kilometers down to 3 kilometers, 600 meters, and finally to 300 meters above the asteroid's surface. The spacecraft is equipped with a comprehensive suite of 11 science payloads designed to study both Kamoʻoalewa and its subsequent target, comet 311P/PANSTARRS. These instruments include cameras, laser ranging systems, spectrometers, radar, and particle analyzers. Notably, the mission also carries the DIANA dust analyzer, an instrument developed in Italy.

Addressing the challenges posed by the asteroid's poorly characterized nature and unknown surface mechanics, Tianwen-2 will employ three distinct sampling techniques to ensure mission success and provide redundancy. These methods include hovering sampling, touch-and-go sampling, and anchoring and attachment sampling. Following the delivery of samples to Earth in late 2027, the spacecraft will utilize Earth's gravity for a maneuver to set it on a course towards the main-belt comet 311P/PANSTARRS, with an expected arrival in 2034.

Zhou highlighted the inherent difficulties of the Tianwen-2 mission, particularly its targeting of a small, poorly understood body in a microgravity environment. The asteroid's unpredictable shape and rapid rotation, which is currently unknown but suspected, present significant challenges for the sampling operations. The lack of a stable, natural orbit further complicates the mission's trajectory planning.

Official updates regarding the Tianwen-2 mission have been notably sparse. While the CNSA released an early update showing an image of one of the spacecraft's solar arrays, and another image on October 1st (China's National Day) captured by a monitoring camera on the robotic arm, detailed trajectory corrections, unlike those provided for the Tianwen-1 Mars mission and some Chang'e lunar missions, have not been publicly shared.

Zhou also took the opportunity to reiterate the broader objectives of China's Tianwen program, seemingly confirming that the Tianwen-3 and Tianwen-4 missions are proceeding as scheduled. Tianwen-3, a Mars sample return mission, is slated for launch in late 2028, utilizing separate Long March 5 rockets for its lander/ascender and orbiter/returner components. Tianwen-4, targeting the Jupiter system, is planned for launch around 2030. This mission will employ a Venus gravity assist and two Earth flybys to reach Jupiter, where it will orbit and study the planet's moons before eventually entering orbit around the Galilean moon Callisto.

Ekhbary News Agency