September 16, 2018 - China Launches Meteorological Satellite

The date you're looking for is actually September 26, 2025, not September 16, 2018. That's when China launched Fengyun-3H, its eighth polar-orbiting meteorological satellite, aboard a Long March 4C rocket from Jiuquan Satellite Launch Center. It now orbits at roughly 836 km altitude, carrying nine instruments that monitor weather, greenhouse gases, and auroras. There's much more to this mission than the launch date alone.

Key Takeaways

• China launched the Fengyun-3H polar-orbiting meteorological satellite, the eighth in the FY-3 series, supporting global weather forecasting and climate research.
• The satellite launched aboard a Long March 4C rocket from Jiuquan Satellite Launch Center, marking the rocket's 58th flight.
• Fengyun-3H was delivered to an 806×810 km, 98.8° sun-synchronous orbit, carrying a payload mass of 2,250 kg.
• The satellite carries nine remote sensing instruments, including GAS-II, MERSI-III, and HIRAS-II, with six activated and returning first-light data.
• Fengyun-3H replaces FY-3D and extends China's polar observation continuity, with a projected service life through at least 2033.

What Is the Fengyun-3H Meteorological Satellite?

China's latest polar-orbiting weather satellite, the Fengyun-3H (FY-3H), launched on September 27, 2025, from the Jiuquan Satellite Launch Center in Gansu Province. Its satellite design places it in Sun-synchronous orbit at 836 km altitude, with a 14:00 ascending crossing time.

Understanding this satellite's mission history helps you appreciate its role. FY-3H replaces FY-3D, which completed nearly eight years of in-orbit operations, and it's projected to remain operational through 2033 or beyond. It's the newest member of China's coordinated afternoon satellite network, operating alongside FY-3F, FY-3E, and FY-3G.

FY-3H supports global weather forecasting, atmospheric chemistry monitoring, and climate change research. Equipped with nine remote sensing payloads, it delivers 70 distinct data products across six major Earth system categories. FY-3H carries a suite of instruments including MERSI, MWTS, and MWHS, among others, enabling detailed atmospheric sounding and spectral imaging across multiple wavelength ranges. The satellite was developed through a collaboration between CMA and CNSA, combining meteorological expertise with national space program resources to advance China's Earth observation capabilities.

Which Rocket Carried Fengyun-3H Into Orbit?

The Long March 4C rocket carried Fengyun-3H into orbit, lifting off from Jiuquan Satellite Launch Center's Launch Area 4 at 19:28 UTC on September 26, 2025. This marked the 58th flight of the Long March 4C, its third mission of 2025.

You'd recognize this three-stage rocket by its 46.97-meter height and 3.8-meter fairing diameter. It generates 2,993 kilonewtons of liftoff thrust, supporting payloads up to 4,200 kg to low Earth orbit.

For this Jiuquan launch, it successfully delivered Fengyun-3H's 2,250 kg mass into a 806 × 810 km, 98.8° sun-synchronous orbit. Notably, this mission set a record for Launch Area 4, completing its fastest turnaround ever at just 10 days after its previous mission. Fengyun-3H is expected to take over in-orbit operations from Fengyun-3D, which had been in service for nearly eight years. The Long March 4C is manufactured by CASC, the China Aerospace Science and Technology Corporation responsible for developing the rocket.

How Fengyun-3H Completes China's Polar Weather Satellite Fleet

With Fengyun-3H now in orbit, China's polar weather satellite fleet is complete. It's the eighth satellite in the FY-3 series and fills the afternoon orbit slot, replacing FY-3D after nearly eight years of service. That transition ensures polar continuity in China's observation network without gaps in coverage.

You can see how fleet redundancy matters here — Fengyun-3H joins a broader system of four near-Earth orbit observation platforms, contributing to a total of 22 Fengyun satellites launched since 1988. Flying at 836 km in a sun-synchronous orbit with a 14:00 ascending equator crossing, it mirrors the standard FY-3 operational configuration. Its designed service life extends through at least 2033, giving China reliable afternoon-orbit coverage for global weather monitoring well into the next decade. The satellite carries nine advanced instruments, including a hyperspectral infrared atmospheric sounder and microwave temperature sounder, to support weather forecasting and climate change monitoring. Much like Canada's Anik A1 satellite, which demonstrated in 1974 that a single orbital platform could provide continent-wide real-time communications, Fengyun-3H underscores how satellites eliminate dependence on land-based infrastructure for large-scale coverage. The launch lifted off from Launch Area 4 at Jiuquan Satellite Launch Center, marking the 58th Chinese orbital launch of 2025.

Why Fengyun-3H Was Built to Replace Fengyun-3D

After nearly eight years in orbit, FY-3D had far outlasted its original 3-4 year design lifespan — but operational degradation eventually made a successor necessary. Its extended run proved the satellite's reliability, yet declining capacity ultimately triggered satellite retirement and a structured mission transition to FY-3H.

You'll notice the replacement wasn't just about filling a gap. FY-3H brings nine effective payloads, delivering 70 products across six major categories compared to its predecessor. It introduces the Greenhouse-gases Absorption Spectrometer II, capable of global greenhouse gas monitoring with a 100-kilometer swath width. MERSI-III, HIRAS-II, and WAI-II each carry measurable technical upgrades in calibration, infrared sensitivity, and auroral imaging.

Together, these advancements ensure China's polar meteorological network continues supporting global weather prediction, climate monitoring, and space weather forecasting without interruption. FY-3D was launched on 14 November 2017 into a Sun-synchronous orbit at an inclination of 98.8°, establishing the baseline from which FY-3H would ultimately build upon. Just as seismic monitoring networks rely on broad geographic coverage and instrument sensitivity to capture and transmit accurate data over vast distances, polar-orbiting meteorological satellites depend on similarly expansive reach and precise instrumentation to deliver reliable global observations.

Nine Instruments That Make Fengyun-3H Powerful

Packed into FY-3H's design are nine instruments that collectively transform raw atmospheric data into actionable meteorological intelligence.

You're looking at a payload engineered to minimize data latency while maintaining sensor redundancy across critical observation functions.

Three standout capabilities define this satellite's power:

• MERSI-III delivers 250–1,000 meter resolution imagery across a 2,800-kilometer swath
• HIRAS-II profiles temperature, humidity, and cloud characteristics with doubled sensitivity over predecessor systems
• WAI-II monitors auroral activity and space weather phenomena for ionospheric research

Together, these instruments produce 70 data products spanning six categories: cloud radiation, sea surface, land surface, atmospheric parameters, atmospheric composition, and space weather.

That breadth makes FY-3H a genuinely comprehensive Earth observation platform rather than a narrowly focused meteorological tool. The quality of data these instruments generate is critical, as CRM data decay principles remind us that even the most advanced collection systems lose value rapidly when outputs go unvalidated or ungoverned. FY-3H is designated as a planned operational SSO Early Morning mission, occupying a distinct orbital slot from the AM and PM satellites already in the constellation. During in-orbit testing, six of nine remote sensing instruments were activated and began returning first-light data from already-operational payloads.

What Does the GAS-II Instrument Actually Measure?

Among FY-3H's nine instruments, the Greenhouse-gases Absorption Spectrometer-II (GAS-II) stands apart for what it targets: not weather itself, but the atmospheric gases driving long-term climate change. It measures concentrations of CO2 and CH4 by detecting how these gases absorb infrared light. You can think of it as a precision scanner that reads atmospheric chemistry from orbit.

GAS-II uses laser absorption technology to achieve ppb-level sensitivity, catching even trace amounts of greenhouse gases. It also performs vertical profiling, mapping how gas concentrations shift at different atmospheric layers rather than just the surface level. With a 100 km swath width, it captures broad geographic coverage on every pass. The result is continuous, high-resolution data supporting emission tracking, carbon cycle research, and international climate inventories. Its spectral resolution of 0.04–0.1 nm enables precise discrimination of individual trace gas absorption signatures across its measurement range. Ground-based validation of such satellite data can be complemented by portable instruments like the ESS Ecosys mass spectrometer, which employs electron impact ionization to identify and quantify trace atmospheric gases down to the ppb range. The importance of accurately tracking atmospheric composition is underscored by the legacy of pasteurization and germ theory, which demonstrated how rigorous scientific methodology can translate laboratory discoveries into technologies with measurable global health and environmental impact.

How Fengyun-3H Tracks Auroras and Space Weather

While GAS-II probes the chemistry of Earth's atmosphere, the Wide-field Auroral Imager-II (WAI-II) looks outward—tracking auroras and the space weather events that drive them. Operating in the 140–180 nm FUV range, WAI-II delivers auroral imaging across a 130°×130° field of view at 10 km resolution.

It monitors magnetospheric coupling by measuring how solar wind energy transfers into Earth's magnetosphere and ionosphere. Here's what WAI-II captures in real time:

• Aurora intensity and oval boundaries across both hemispheres simultaneously
• Precipitating particle concentrations linked to geomagnetic storms and substorms
• Ionospheric weather distributions supporting space weather forecasting

Passing over the poles 14 times daily, Fengyun-3H gives you continuous, high-frequency coverage of polar dynamics that ground-based systems simply can't match. Much like how ingredient branding transformed anonymous processors into household names, WAI-II's data transforms invisible space weather phenomena into actionable, consumer-grade forecasting signals. The satellite's microwave instruments have already demonstrated this capability by capturing the Arctic polar vortex during early trial operations.

What Fengyun-3H's 70 Data Products Actually Deliver

Beyond auroral imaging, Fengyun-3H's instrument suite feeds into 70 operational data products spanning five core categories: cloud radiation, sea surface, land surface, atmospheric parameters, and atmospheric composition.

You're looking at cloud diagnostics that cover everything from cloud top height and optical depth to liquid water columns and type classifications.

Sea surface products deliver temperature, ice cover, albedo, wind speed, and precipitation intensity.

On land, you'll find surface temperature, NDVI, leaf area index, soil moisture, and biomass estimates.

Atmospheric profiling captures temperature, humidity, tropopause boundaries, and boundary layer heights.

Composition products track ozone, NO2, SO2, CO2, CH4, and aerosol optical depth.

Radiative fluxes at the top of atmosphere complete the picture, giving researchers a comprehensive dataset for weather forecasting, climate monitoring, and air quality assessment. This kind of long-term atmospheric data collection mirrors the mission of ground-based facilities like Canada's Eureka Weather Station, established in 1947 on Ellesmere Island to monitor northern climate conditions in one of the most remote environments on Earth.

How Fengyun-3H Monitors Climate Change and Natural Disasters

Fengyun-3H's climate and disaster monitoring capabilities center on two headline instruments: the Greenhouse-gases Absorption Spectrometer II (GAS-II) and the Microwave Radiation Imager (MWRI). Together, they strengthen emission verification efforts and track ecosystem resilience across changing environments.

Here's what these instruments deliver:

• GAS-II scans four spectral bands across a 100km swath, measuring column concentrations of major greenhouse gases globally
• MWRI captures all-weather land surface temperatures throughout daily cycles, improving accuracy in cold and mountainous regions by accounting for soil freeze-thaw states
• Combined outputs support hydrological forecasting, disaster response, and biosphere anomaly detection through polar-orbiting coverage

You're looking at a system that doesn't just observe weather—it connects atmospheric composition data directly to climate diagnosis, natural disaster mitigation, and refined Earth system monitoring. The satellite forms a network with three previously launched Fengyun-3 series satellites, shortening global weather forecast update times from six hours to four hours. This kind of data-rich, networked monitoring mirrors the ambitions of early computing innovators, such as those behind the Xerox Star 8010, which introduced integrated file servers and Ethernet networking to connect office systems and share information across multiple workstations in 1981.

How Fengyun-3H Strengthens Global Numerical Weather Prediction

When it comes to numerical weather prediction (NWP), Fengyun-3H doesn't just add another data stream—it reshapes how models see the atmosphere in three dimensions. It delivers 70 products across six categories, giving you temperature and humidity profiles that sharpen medium-range forecasts.

Its 3D atmospheric detection data strengthens data assimilation, letting models ingest multi-sphere Earth system inputs more accurately. You get cloud radiation and atmospheric composition data that feed directly into model calibration, reducing forecast errors before they compound.

Working alongside FY-3E, it closes observational gaps and achieves 100% global coverage every six hours. It also coordinates with NOAA and EUMETSAT through WMO, ensuring your NWP models draw from a globally consistent, high-resolution observational network that improves forecast reliability across all timescales. The pursuit of coordinated, large-scale weather data collection traces back to the Smithsonian Institution's 1849 establishment of a national network of weather observation stations, a foundation that modern satellite systems continue to build upon. As part of China's second-generation polar-orbiting meteorological satellites, Fengyun-3H represents a significant advancement in global observation infrastructure. The satellite is equipped with nine advanced instruments, including a medium-resolution spectral imager, hyperspectral infrared atmospheric sounder, and microwave temperature sounder, each contributing specialized observational capabilities to the mission.