Long March 3B/E | Tianwen-2
Long March 3B/E • Long March
📝 Mission Description
China's Tianwen-2 Mission: Pioneering Asteroid Sampling and Comet Exploration
On May 28, 2025, China is set to launch its ambitious Tianwen-2 mission aboard a Long March 3B/E rocket from the Xichang Satellite Launch Center. This endeavor marks a significant step in China's growing portfolio of deep-space exploration, combining asteroid sample return with comet observation in a single, multifaceted spacecraft. Tianwen-2 builds on the success of previous missions like Tianwen-1, which achieved Mars orbit and rover deployment, underscoring Beijing's push toward self-reliant space capabilities amid international competition.
At the heart of Tianwen-2 are dual objectives: retrieving samples from the near-Earth asteroid 469219 Kamoʻoalewa (provisionally named 2016 HO3) and conducting long-term observations of the main-belt comet 311P/PANSTARRS. The spacecraft, weighing approximately 4 tons at launch, is equipped with advanced instruments including high-resolution cameras, spectrometers, and a robotic arm for sample collection. It will employ two innovative methods to gather material from Kamoʻoalewa: a touch-and-go maneuver, where the probe briefly contacts the surface to scoop up regolith, and an anchor-and-drill approach for deeper subsurface samples. This dual strategy enhances redundancy and scientific yield, potentially revealing insights into the asteroid's composition, which may hold clues to the solar system's early formation. After collecting up to several kilograms of samples, a return capsule will detach and deliver them to Earth around late 2027, while the main orbiter continues its journey to rendezvous with 311P/PANSTARRS in the mid-2030s. There, it will study the comet's nucleus, coma, and tail, providing data on volatile compounds and dust dynamics that could inform models of cometary evolution and their role in delivering water to planets.
The Long March 3B/E rocket, a variant of China's reliable Long March family, is tailored for geosynchronous transfer orbit (GTO) missions like this one. Standing about 56 meters tall with a diameter of 3.35 meters, it features a three-stage core boosted by four liquid strap-on engines, all fueled by unsymmetrical dimethylhydrazine (UDMH) and nitrogen tetroxide. The enhanced "E" version incorporates upgraded engines and a larger payload fairing, boosting its GTO capacity to around 5.5 tons—ideal for Tianwen-
ℹ️ Official Details
Tianwen-2 is a planned Chinese asteroid sample return and comet orbiter mission due for launch in May 2025. The spacecraft will visit the Near Earth asteroid 469219 Kamoʻoalewa (2016 HO3), collecting samples from its surface using both touch-and-go and anchor-and-drill approaches. It will return the samples back to Earth around 2.5 years after launch, with the main spacecraft proceeding to visit the main-belt comet 311P/PANSTARRS in the mid-2030s.
🎯 Post-Launch Analysis
The Long March 3B/E launch of Tianwen-2 on May 28, 2025, achieved a successful orbital insertion and payload deployment, marking a significant milestone for China’s deep-space exploration program. The rocket performed flawlessly, delivering the spacecraft into its intended trajectory with precision. Tianwen-2, designed for asteroid sample return and comet observation, was deployed without anomalies, initiating its journey to Near Earth asteroid 469219 Kamoʻoalewa for sample collection using innovative touch-and-go and anchor-and-drill methods. Key engineering outcomes include validated launch vehicle reliability and spacecraft systems readiness for long-duration missions. This success reinforces confidence in China’s capability to execute complex interplanetary missions, paving the way for future endeavors like sample returns and comet studies. The mission’s progress will offer critical data for refining deep-space navigation and sampling technologies, shaping strategies for subsequent explorations in the 2030s.