China launches Tianwen-2 to chase Moon-origin asteroid, explore hybrid comet

Yahoo

30-05-2025

China has launched its most ambitious deep space mission yet.
On Wednesday, the Tianwen-2 probe lifted off atop a Long March 3B rocket at 1:31 pm Eastern (17:31 UTC) from the Xichang Satellite Launch Center in Sichuan province.
The mission aims to collect samples from a near-Earth asteroid and later survey a comet in the main asteroid belt, marking the country's first asteroid sampling effort.
Tianwen-2 is now en route to asteroid 469219 Kamoʻoalewa (2016 HO3), a small rocky body orbiting close to Earth.
The probe is expected to reach the asteroid in mid-2026 and return samples to Earth in 2027.
After the sample return, it will continue its journey toward comet 311P/PANSTARRS, with arrival expected around 2035.
The China Aerospace Science and Technology Corporation (CASC) confirmed the successful launch just over an hour after liftoff.
Xinhua reported that 'the spacecraft unfolded its solar panels smoothly,' and the China National Space Administration (CNSA) officially declared the mission a success.
Discovered in 2016 by researchers in Hawaii, Kamoʻoalewa is believed to be a fragment of the Moon. Scientists hope to analyze its structure, mineral content, and origin.
It is roughly 40 to 100 meters in diameter. Depending on surface conditions, the mission will employ three sampling methods — hover sampling, touch-and-go, and anchored drilling.
Tianwen-2 will then use Earth's gravity to redirect itself toward comet 311P.
The comet orbits between Mars and Jupiter and displays asteroid-like behavior, making it ideal for studying transitional objects in the solar system.
Reaching and sampling small celestial bodies is more challenging than orbiting planets. The mission must navigate weak and irregular gravity fields, which rule out traditional orbiting methods.
'These bodies have extremely weak and irregular gravity fields,' Franco Perez-Lissi, Ramses mission systems engineer at the European Space Agency (ESA), told SpaceNews. 'So we cannot rely on traditional orbiting like we do around the planet.'
Tianwen-2 must closely match the asteroid's rotation and speed for successful sampling.
Perez-Lissi likened the maneuver to 'trying to dock a boat with a mountain floating in space and tumbling really unpredictably and with almost no gravity.'
The probe carries 11 science payloads, including spectrometers, high-resolution cameras, a radar sounder, and particle detectors.
These will study the composition, geological features, magnetic fields, and solar wind interactions at both the asteroid and the comet.
Past missions like NASA's OSIRIS-REx and JAXA's Hayabusa2 have returned organic materials, including amino acids and nucleobases—key building blocks of life.
Tianwen-2 follows the successful Tianwen-1 Mars mission and precedes plans for Mars sample return and Jupiter system exploration.
These missions are part of a long-term roadmap that includes the International Lunar Research Station and a Venus sample return.
According to Xinhua, Shan Zhongde, head of the CNSA, 'expressed his expectation of yielding groundbreaking discoveries and expanding humanity's knowledge of the cosmos.'
China continues to invest heavily in space, with its Tiangong space station now operational and a crewed Moon mission planned for later this decade.
Tianwen-2 could mark another leap forward in China's 'space dream,' as articulated by President Xi Jinping.