China’s Tianwen-2 mission will mark the country’s first attempt to survey and sample an asteroid and put it in league with the US, Russia and Japan. Tianwen-2 will investigate a nearby asteroid called Kamo’oalewa, which orbits the sun at a distance relatively close to Earth.The entire mission could last a decade. If it successfully retrieves and returns samples from the asteroid, it will continue to explore the solar system with a second trip to the main asteroid belt.When will Tianwen-2 launch?Tianwen-2 will launch at the end of May 2025 on a Long March 3B rocket from the Xichang Satellite Launch Centre in Sichuan province, according to a statement published by the China National Space Administration (CNSA). CNSA has yet to confirm an exact launch date.Where is Tianwen-2 going?The first target for Tianwen-2 will be the asteroid Kamo’oalewa. If successful, it will mark the first time China has collected samples from an “interplanetary” body in the solar system. China has, however, previously returned samples from the moon.How will it retrieve samples?Tianwen-2 will attempt to sample Kamooalewa with a “touch-and-go” technique that was successfully used by the OSIRIS-Rex and Hayabusa2 missions. This method uses an extended robotic arm to scrape an asteroid’s surface as the probe flies past.It will also attempt to land on the surface using a second “anchor and attach” technique. This would see four robotic arms extend and drill into the surface to retrieve material.As with other space sample missions, the samples would then be dropped back to Earth before the probe continues towards its secondary mission in the asteroid belt.Interplanetary bodies — literally natural space objects between planets, including asteroids, comets and meteors — are common near Earth and have been explored for years by other space agencies, such as NASA, Roscosmos and JAXA.After Kamo’oalewa, Tianwen-2’s next destination is the comet 311P/PANSTARRS. Comet 311P/PANSTARRS in the solar system’s main “asteroid belt” between Mars and Jupiter. The probe won’t gather samples from the comet but will instead orbit and analyze its composition.What is Kamo’oalewa?Kamo’oalewa is an unusual asteroid, estimated to be between 40-100 meters (131–328 feet) in diameter.It’s described as a “quasi-satellite” because, while it orbits the sun , its current location near Earth means it also loops around our planet in the process.Astronomers think Kamo’oalewa may be a boulder that was blasted off the surface of our moon following an impact with another space object.It will take about two-and-a-half years for Tianwen-2 to complete its initial mission to Kamo’oalewa.What does Tianwen mean?Tianwen is the name of a work by Chinese poet Qu Yuan, who died around 278 BCE. It translates as “Heavenly questions.”This series of missions began with the launch of Tianwen-1 in July 2020, which sent an explorer to Mars.After landing on the surface in May 2021, the rover was put into hibernation mode but failed to restart as planned at the end of 2022.Tianwen-3 is the next scheduled mission, due to begin in 2028. That will be China’s first attempt to return samples from the surface of Mars.
