HELSINKI — A senior Chinese space scientist and delegate to the country’s national congress is proposing the prioritization of an unprecedented orbiter mission to ice giant Neptune.
Chinese researchers have published concept studies for Neptune orbiter missions in recent years which would require technological breakthroughs but could deliver huge scientific payoffs. A July 2025 study outlined science objectives and payloads and identified a launch window of around 2033. Neptune has not been visited since NASA’s Voyager 2 flyby in 1989.
Wang Wei, an academician of the Chinese Academy of Sciences (CAS), and a researcher at the China Aerospace Science and Technology Corporation (CASC), made the proposal to prioritize a Neptune orbiter mission as a deputy to the National People’s Congress (NPC), during China’s ongoing political sessions in Beijing.
Wang said Neptune preserves a large amount of gas from the early stages of the Solar System’s formation, according to CASC-affiliated China Aerospace News. Neptune contains information about the conditions of the protosolar nebula and the formation of the planets, providing an invaluable setting for studying both our Solar System and exoplanets, according to Wang, and thus holds enormous scientific value.
Ice giants Uranus and Neptune are of great scientific interest, the only spacecraft to visit either planet was NASA’s Voyager 2 during flybys in the 1980s. A new decadal survey from the National Academies of Sciences published in 2022 stated that a Uranus Orbiter and Probe (UOP) should be the highest priority large mission.
Wang is now calling for China to seize a historic opportunity to conduct a world-first orbital study of Neptune, building on the country’s recent advances in deep space exploration capabilities and progress in space nuclear power technologies.
Wang called for including a Neptune orbiter as a priority project in national science and technology plans. He also urged early research and development of key technologies, strengthened international cooperation while maintaining Chinese leadership, and long-term multidisciplinary exchanges to develop China’s planetary science and engineering workforce.
The recently proposed concept calls for radioisotope thermoelectric generators (RTGs), as the spacecraft would operate roughly 4.5 billion kilometers from Earth, where solar power is not viable. The spacecraft would carry 11 science payloads and, after arrival at Neptune, the spacecraft would deploy an atmospheric entry probe into the planet’s atmosphere and enter a long-term resonant orbit. It would then observe the planet’s rings, geological dynamics and magnetosphere, and assess the potential habitability of Triton’s subsurface ocean.
Separately, Wang Runfu, of CASC’s China Academy of Space Technology (CAST) and a member of the National Committee of the Chinese People’s Political Consultative Conference (CPPCC)—the consultative counterpart to the NPC—said that space nuclear energy and nuclear power are key carriers of “new productive forces” in the space sector.
This year, China’s annual political sessions will see the discussion and finalizing of the country’s 15th Five-year plan, setting a series of national goals and priorities for the period 2026-2030. A draft of the plan would see the commercial and wider space sector elevated to be an emerging “pillar industry,” while also setting out ambitious deep space, satellite infrastructure and space industrial capacity objectives. Solar system boundary exploration is noted as one of the deep space objectives, following the recent publication of a detailed mission study, indicating China’s commitment to launching missions powered by space nuclear technology.
A more detailed space white paper outlining the country’s key objectives for space to the end of the decade is expected to be published by the China National Space Administration (CNSA) later in the year. This document could indicate if China has opted to begin formal studies into a Neptune orbiter mission. The latest space white paper, published in January 2022, included studying plans for “boundary exploration of the solar system.”
China put a spacecraft in orbit around Mars and a rover on the surface with Tianwen-1 in 2021, and last year launched the Tianwen-2 near-Earth asteroid and main belt comet mission. China is planning to launch the Tianwen-3 Mars sample return and Tianwen-4 Jupiter and Callisto orbiter missions during the 15th Five-year plan period.