| Tianwen-2 天问二号 | |||||||||
| Mission Type: | Asteroid sample return Comet orbiter/lander | ||||||||
| Operator: | CNSA | ||||||||
| Mission Duration: | 10 years (planned) | ||||||||
| Manufacturer: | CAST | ||||||||
| Launch Mass: | ≤2000kg (4,000lb) | ||||||||
| Launch Date: | May 2025 (planned) | ||||||||
| Launch Rocket: | Long March 3B | ||||||||
| Launch Site: | Xichang | ||||||||
| Launch Contractor: | CASC | ||||||||
| Interplanetary: |
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| Programme: | Tianwen program | ||||||||
| Previous Mission: | Tianwen-1 | ||||||||
| Next Mission: | Tianwen-3 | ||||||||
Tianwen-2 is a planned Chinese asteroid sample return and comet exploration mission that is currently under development.[3] Tianwen-2 was originally known as ZhengHe.
Tianwen-2 is scheduled to be launched on a Long March 3B rocket in May 2025.[4] It will use solar electric propulsion to explore the co-orbital near-Earth asteroid 469219 Kamoʻoalewa and the main-belt comet 311P/PANSTARRS.[5] [6] The spacecraft will rendezvous with Kamoʻoalewa and conduct remote sensing observations in orbit, before landing on the asteroid to collect a sample of of regolith.[7] [8] A nano-orbiter and nano-lander will be deployed to conduct remote sensing and sampling observations, and explosives will be used to expose potential subsurface volatiles for detection.[9]
The spacecraft will use both anchor-and-attach and touch-and-go methods to attempt collection of a sample from the asteroid. It would be the first time an anchor-and-attach method has been used on an asteroid, as both OSIRIS-REx and Hayabusa2 used touch-and-go.[10]
Tianwen-2 will then return to Earth to drop off a return capsule containing the sample and conduct a gravity assist maneuver to propel the spacecraft toward 311P/PANSTARRS.[11] A flyby of an unnamed asteroid may also be attempted en route to 311P/PANSTARRS. Remote sensing and in-situ measurements will be conducted at 311P/PANSTARRS for at least one year.[12]
The original name of this mission referenced the 15th century Ming Dynasty explorer Zheng He.
In 2018, a deep space exploration roadmap covering the 2020–2030 timeframe was proposed by researchers at the Chinese Academy of Sciences,[13] which included an asteroid exploration mission planned for launch around 2022 or 2024.[14] [15] In spring 2019, after a design study for the mission was carried out by the Chinese Academy of Space Technology (CAST), the CNSA began soliciting international proposals for scientific instruments to be carried on Tianwen-2.
Tianwen-2 will incorporate several types of instruments, including wide/narrow angle multispectral and color cameras, a thermal emission spectrometer, a visible/near-infrared imaging spectrometer, a mass spectrometer, a magnetometer, and a charged/neutral particle and dust analyzer. International contributions to these payloads are being encouraged.