Tianwen-4 by CNSA: status and timeline

Milestones

Next · Mission design and instrument selection

Two-spacecraft plan presented at IAC in Paris21 Sep 2022Complete.
Callisto focus and 2029 launch presentedDec 2023Complete.
Preliminary instrument list publishedMay 2024Complete.
Mission design and instrument selectionNowCurrent milestone.
Launch on a Long March 5 from WenchangTarget Sep 2029Not yet reached.
Venus gravity assistTarget 2030Not yet reached.
Earth gravity assistsTarget 2033Not yet reached.
Arrive in orbit around JupiterTarget Dec 2035Not yet reached.
Uranus flyby by the small probeTarget Mar 2045Not yet reached.

Most important updates

Upcoming

Sep 2029Launch on a Long March 5 from Wenchangin about 151 weeks (next)
Sep 2029Tianwen-4 launch
2030Venus gravity assist
2033Earth gravity assists
Dec 2035Arrive in orbit around Jupiter
Mar 2045Uranus flyby by the small probe

Current obstacles

Power far from the SunAt about 800 million km from the Sun, sunlight is weak; Chinese engineers named generating enough power as work in progress.
Goals and approval still being setPublished plans list a launch date and instruments, but science goals were still under discussion and no final go-ahead has been announced.

Physics limits

Sunlight is 25 times weaker at JupiterLight falls off with the square of distance; at 5.2 times Earth's distance a solar panel gets about 4% of the power, so panels must be huge or a nuclear source used.
Messages take most of an hourRadio signals take roughly 35 to 50 minutes to reach Jupiter, so the craft must fly itself through orbit insertion and flybys.

How it works

4 parts

Slingshots

Borrowing speed from Venus and Earth

The rocket alone cannot throw the craft to Jupiter, so it flies past Venus once and Earth twice, picking up speed from each planet's gravity.

Split up

Two craft, two destinations

Before reaching Jupiter, a small probe separates and keeps going toward Uranus, while the main craft brakes into orbit around Jupiter.

Callisto

Why Callisto, not Europa

Callisto lies outside Jupiter's harshest radiation, so electronics last longer, and its ancient surface records how the moon system formed.

Impactor

Hitting the moon to look inside

Plans include an impactor, letting the orbiter watch the crash and study material thrown up from below the surface.

Spec sheet

Spec	Tianwen-4
Spacecraft	Jupiter–Callisto orbiter + Uranus flyby probe^R (reported)
Uranus probe mass	A few hundred kg^R (reported)
Rocket	Long March 5 (one launch for both)^R (reported)
Launch to Jupiter orbit	About 6 years^E (estimated)
Distance from the Sun at Jupiter	About 800 million km^R (reported)

^R reported by the company · ^E our estimate

Update log

2 updates

Thu 21 Dec 2023

Minor: Tianwen-4 plan: launch September 2029, Jupiter orbit 2035, Uranus flyby 2045PressOther

Wed 21 Sep 2022

Minor: CNSA presents a Jupiter and Uranus mission: two spacecraft on one Long March 5 around 2030PressOther

About CNSA

The team behind Tianwen-4

CNSA

China lunar exploration, Chang'e, Tianwen missions

The China National Space Administration (CNSA) is China's government civil space agency, established in 1993. It manages the country's lunar and planetary exploration programs, including the Chang'e lunar missions and Tianwen deep space exploration projects.

China's civil space agency founded in 1993. Operates the world's most active lunar program, deploying hardware constantly.
Chang'e missions map south pole ice; Tianwen explores asteroids and comets for sample return.
Manages lunar, planetary, orbital and space station programs in parallel.

cnsa.gov.cn (opens cnsa.gov.cn)Company profile →

Founded: 199333 yrs
Headquarters: China
Status: Government
Valuation: government
Works in: SpaceflightPlanetary missions
Coverage: 4 programs · 3 updateslatest 1 Mar 2026checked 11 Oct
Suppliers: China Aerospace Science and Technology Corporation (CASC) (opens spacechina.com)