More GuoWang Satellites Reach Orbit [Long March 5B/YZ-2 Y7]

China's largest rocket has delivered another batch of mega-constellation satellites.

The Long March 5B Y7 vehicle during first-stage flight.

A Long March 5B, one of China’s largest rockets, lifted off from a very foggy Launch Complex 101 at the Wenchang Space Launch Site at 04:10 am China Standard time on April 29th (20:10 pm Universal Coordinated Time on April 28th) heading toward a polar orbit carrying a group of satellites.

Atop of the Long March 5B today were the third batch of GuoWang (郭望) mega-constellation satellites. Like the previous GuoWang mission for the rocket, ten satellites were attached to a Yuanzheng-2 upper-stage.

Few details have been shared about the design of GuoWang satellites, but a slide from one of Space Pioneer’s presentations states that each satellite weighs approximately 600 kilograms. Two different satellite variants are believed to be in use for the constellation, a larger version used on vehicles like the Long March 5B while smaller ones are used when launched atop of rockets similar to the Long March 8A. An electric propulsion system is likely in use due to a planned operational orbit above 1000 kilometers in altitude, as it would be the most efficient means of propulsion to deorbit each spacecraft once they reach the end of their operational lives.

The GuoWang constellation is operated by China Satellite Network Group, a state-owned enterprise, and wholly backed by the Chinese government. By the 2030s up to 13,000 satellites could be in orbit providing worldwide internet services, however China-focused services will be the immediate priority.

GuoWang is currently trailing the Qianfan (千帆) mega-constellation, also set to provide space-based internet services, with twenty-nine satellites now in orbit, compared to Qianfan’s ninety. Qianfan did have a five-month head start over GuoWang with launches, additionally having launched three satellite batches by the time GuoWang deployed one.

Patches from the China Academy of Launch Vehicle Technology (left) and the Shanghai Academy of Spaceflight Technology (right) for the Long March 5B Y7 launch mission.

Once again, a Yuanzheng-2 upper-stage was atop of the rocket, preventing its core-stage from entering orbit. A handful of Yuanzheng upper-stages are used across most Long March launch vehicles as an optional extra stage for delivering satellites into higher orbits or to deploy multiple satellites into various orbits. These stages burn storable propellants to perform multiple maneuvers in orbit before releasing their payloads.

This was the Long March 5 series’ (Long March 5 and 5B) first flight of the year, following its previous flight four and a half months ago in mid-December 2024. The Long March 5 series of rockets is currently believed to be working toward ten flights per year, with at least two more flights planned this year. So far, the vehicle series has achieved a two-month turnaround twice. This would see the rocket series flying roughly every five weeks. With this increase in cadence, the Long March 5B has had a reported vehicle cost close to SpaceX’s reusable Falcon 9.

Today’s launch was the 6th mission for the Long March 5B, the 14th launch for the Long March 5 series, and the 573rd launch of the Long March launch vehicle series. This was also the 24th launch from China in 2025.

Local launch live stream via International Rocket Launches and ThatSpaceDogeGuy on YouTube.

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Check out the previous Long March 5 launch

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What is the Long March 5B?

This section is for those less familiar with China's Long March series of launch vehicles.

The Long March 5B is China's most capable vehicle for sending payloads to low Earth orbit, and was developed by the China Academy of Launch Vehicle Technology and based on the Long March 5, removing the second-stage. The one-and-a-half-stage launch vehicle is fuelled with liquid hydrogen and liquid oxygen in its first-stage along with rocket-grade kerosene and liquid oxygen in four boosters.

The payload capacity of the launch vehicle is currently as follows:

• 25,000 kilograms to low Earth orbit

The Long March 5B Y7 vehicle inside the vehicle assembly building before its rollout to the launch pad.

The Long March 5B's first-stage is powered by two YF-77 engines, which produce 143 tons of thrust using liquid hydrogen and liquid oxygen. To assist with liftoff, the rocket is equipped with four side boosters, each powered by two YF-100 engines that generate 245 tons of thrust using rocket-grade kerosene and liquid oxygen, providing a combined booster thrust of 979 tons. Together, the first stage and boosters deliver a total thrust of 1,122 tons.

On the launchpad, the Long March 5B stands at up to 53.66 meters tall and weighs up to 837,500 kilograms fully fuelled. The first-stage has a diameter of five meters, while the four boosters have a diameter of 3.35 meters, and the fairing has a diameter of 5.2 meters.

So far the Long March 5B has only flown from the Wenchang Space Launch Site, on the east coast of Hainan province.

The Long March 5B Y7’s fairing heading to the vehicle assembly building after encapsulation of its payloads.

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