Dark matter, Earth 2.0, and more: These 13 missions could be China’s next big space mission

China will select half a dozen space-mission proposals in the next few months from a candidate list of 13, and may adopt their picks as soon as 2024 for operations later this decade.

The 13 proposals belong to China’s New Horizon Program, and they span the fields of heliophysics, planetary science, and astrophysics. A paper titled “China’s Space Science Program (2025－2030): Strategic Priority Program on Space Science (III),” published in the Chinese Journal of Space Science, describes these potential new missions.

In recent years the nation has accelerated its presence in space with missions like Tianwen-1 to Mars, Chang’e-4 to the lunar farside, and the first spacewalk on their Tiangong space station in low-Earth orbit. The new paper expands on the country’s ambitious plans.

According to the document, a panel of experts will evaluate the 13 proposals, prioritizing some ideas over others. These recommendations will then head over to officials at the Chinese Academy of Sciences Headquarters, who will whittle down the list and select five to seven of them to move forward. Then by mid-2023 the New Horizon Program, also known as the Strategic Priority Program III or SPP III, will head into its next phase when officials determine a plan and budget for their picks. They aim to get this program approved by 2024, the paper states.

“During the implementation of the mission, NSSC [National Space Science Committee]/CAS will continue to uphold the open policy, welcoming international cooperation at every level such as mission level, payload level, or just data sharing,” it says.

Here is a list of the 13 project candidates.

There are three proposed astrophysics missions.

• Enhanced X-ray Timing and Polarimetry (eXTP) Mission, “a powerful X-ray observatory orbiting the Earth at 550 km, can continuously monitor the X-ray sky and enable multi-messenger studies for gravitational waves and neutrino sources.”
• DArk Matter Particle Explorer-2 (DAMPE-2), designed to detect “possible characteristic features of gamma rays and electrons/positrons from dark matter annihilation or decay… as well as transients associated with events of gravitational waves, tidal disruptions, and high energy neutrinos.”
• Discovering the Sky at the Longest Wavelength (DSL) Mission, a “linear array of micro-satellites placed on a lunar orbit” to “provide new insights into the various astrophysical processes in the planets and stars, the Milky Way, galaxies and supermassive black holes.”

There are two proposed exoplanet missions.

• Closeby Habitable Exoplanet Survey (CHES) mission, which is “devoted to discover Earth-like planets of the nearby solar-type stars” and conduct a “census on the nearby planetary systems.”
• Earth 2.0 (ET) Mission, designed to find “the elusive habitable Earth-like planets orbiting stars just like a sun.”

There are four proposed heliophysics missions.

• SOlar Ring (SOR) Mission, which “aims to address the origin of [the] solar cycle, the origin of solar eruptions and the origin of severe space weather with necessary in-situ instruments and imagers.”
• Solar Polar-orbit Observatory (SPO), which seeks to “directly image the solar poles in an unprecedented way … to construct data-driven global heliospheric numerical models which serves as the foundation for space weather prediction.”
• Earth-occulted Solar Eclipse Observatory (ESEO), “a solar telescope near the second Lagrange point (L2) of the Earth-Sun system exploiting the Earth’s occultation to explore the inner corona.”
• Chinese Heliospheric Interstellar Medium Explorer (CHIME), which “might provide the first in situ measurements of pristine interstellar gas and dust in their high-density regions at 2-3 AU from the Sun.”

There are four proposed Solar System and Earth missions.

• E-type Asteroid Sample Return (ASR) Mission, “aimed to explore the E-type 1989 ML asteroid and return samples collected from up to three sites.”
• Venus Volcano Imaging and Climate Explorer (VOICE) Mission, “to investigate Venusian geological evolution, atmospheric thermal-chemical processes, surface-atmosphere interactions, and habitable environment and life in the clouds.”
• Climate and Atmospheric Components Exploring Satellites (CACES), which would support “China’s targets of achieving a carbon peak by 2030 and carbon neutrality by 2060.”
• Ocean Surface Current multiscale Observation Mission (OSCOM), “dedicated to the frontier of ocean multiscale dynamics and energetics based on satellite Doppler oceanography.”

These 13 proposals were the winners of earlier program stages. SPP III had 17 proposals at the end of 2021, after soliciting concepts from research institutes, universities and industries across China, the document states.