''Tianwen-2'', formerly known as ''ZhengHe'', is a planned Chinese asteroid sample-return and comet exploration mission that is currently under development.

Overview

''Tianwen-2'' is planned to be launched by a

Long March 3B The Long March 3B (, ''Chang Zheng 3B''), also known as the CZ-3B and LM-3B, is a Chinese orbital launch vehicle. Introduced in 1996, it is launched from Launch Area 2 and 3 at the Xichang Satellite Launch Center in Sichuan. A three-stage rock ...

rocket around 2025. It will use

solar electric propulsion Solar electric propulsion (SEP) refers to the combination of solar cells and electric thrusters to propel a spacecraft through outer space. This technology has been exploited in a variety of spacecraft by the European Space Agency (ESA), th ...

to explore the

co-orbital In astronomy, a co-orbital configuration is a configuration of two or more astronomical objects (such as asteroids, moons, or planets) orbiting at the same, or very similar, distance from their primary, i.e. they are in a 1:1 mean-motion resonan ...

near-Earth asteroid

469219 Kamoʻoalewa 469219 Kamoʻoalewa (), provisionally designated , is a very small asteroid, fast rotator and near-Earth object of the Apollo group, approximately in diameter. At present it is a quasi-satellite of Earth, and currently the smallest, closest, ...

and the

main-belt comet Active asteroids are small Solar System bodies that have asteroid-like orbits but show comet-like visual characteristics. That is, they show comae, tails, or other visual evidence of mass-loss (like a comet), but their orbit remains within Jup ...

311P/PANSTARRS. The spacecraft will rendezvous with Kamoʻoalewa and conduct

remote sensing Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring information about Eart ...

observations in orbit, before landing on the asteroid to collect a sample of of

regolith Regolith () is a blanket of unconsolidated, loose, heterogeneous superficial deposits covering solid rock. It includes dust, broken rocks, and other related materials and is present on Earth, the Moon, Mars, some asteroids, and other terrestr ...

. 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 Volatiles are the group of chemical elements and chemical compounds that can be readily vaporized. In contrast with volatiles, elements and compounds that are not readily vaporized are known as refractory substances. On planet Earth, the term ...

for detection. 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 OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) is a NASA asteroid-study and sample-return mission. The mission's primary goal is to obtain a sample of at least from 101955 Bennu, a carbona ...

and '' Hayabusa2'' used touch-and-go. ''Tianwen-2'' will then return to Earth to drop off a return capsule containing the sample and conduct a

gravity assist In orbital mechanics and aerospace engineering, a gravitational slingshot, gravity assist maneuver, or swing-by is the use of the relative movement (e.g. orbit around the Sun) and gravity of a planet or other astronomical object to alter the p ...

maneuver to propel the spacecraft toward

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...

, where a second gravity assist will be performed to direct it to 311P/PANSTARRS. 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. The original name of this mission referenced the 15th century

Ming Dynasty The Ming dynasty (), officially the Great Ming, was an imperial dynasty of China, ruling from 1368 to 1644 following the collapse of the Mongol-led Yuan dynasty. The Ming dynasty was the last orthodox dynasty of China ruled by the Han peo ...

explorer ZhengHe.

History

In 2018, a deep space exploration roadmap covering the 2020–2030 timeframe was proposed by researchers at the

Chinese Academy of Sciences The Chinese Academy of Sciences (CAS); ), known by Academia Sinica in English until the 1980s, is the national academy of the People's Republic of China for natural sciences. It has historical origins in the Academia Sinica during the Republi ...

, which included an asteroid exploration mission planned for launch around 2022 or 2024.. In spring 2019, after a design study for the mission was carried out by the

Chinese Academy of Space Technology The China Academy of Space Technology (CAST) () is a Chinese space agency and subordinate of China Aerospace Science and Technology Corporation (CASC). The agency was founded on 20 February 1968, and is the main spacecraft development and prod ...

(CAST), the

CNSA China National Space Administration (CNSA; ) is the government agency of the People's Republic of China that is responsible for civil space administration and international space cooperation, including organizing or leading foreign exchanges ...

began soliciting international proposals for scientific instruments to be carried on ''Tianwen-2''.

Instruments

''Tianwen-2'' will incorporate several types of instruments, including wide/narrow angle multispectral and color cameras, a

thermal emission spectrometer The Thermal Emission Spectrometer (TES) is an instrument on board Mars Global Surveyor. TES collects two types of data, hyperspectral thermal infrared data from 6 to 50 micrometres (μm) and bolometric visible-NIR (0.3 to 2.9 μm) measurements. T ...

, a visible/near-infrared

imaging spectrometer An imaging spectrometer is an instrument used in hyperspectral imaging and imaging spectroscopy to acquire a spectrally-resolved image of an object or scene, often referred to as a datacube due to the three-dimensional representation of the data. ...

, a

mass spectrometer Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a '' mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is us ...

, a magnetometer, and a charged/neutral particle and dust analyzer. International contributions to these payloads are being encouraged. The United Kingdom is considering a proposal for a penetrator to deliver a

to probe the subsurface ice of 311P/PANSTARRS.

References

External links

{{Portal bar, Astronomy, Space, Spaceflight Chinese space probes Sample return missions 2025 in spaceflight 2025 in China Missions to comets Missions to near-Earth asteroids Proposed space probes