Space-Based Communications Infrastructure Expands [Long March 7A Y15]

Another ChinaSat communications spacecraft is headed out to geostationary orbit.

The Long March 7A Y15 vehicle lifting off from Launch Complex 201 at the Wenchang Space Launch Site.

Blasting off from Launch Complex 201 at the Wenchang Space Launch Site on May 20th at 19:50 pm China Standard Time (11:50 am Universal Coordinated Time), a Long March 7A headed for a geostationary transfer orbit, carrying a single satellite.

The sole satellite being launched was ChinaSat-3B (中星3B), developed by the China Academy of Space Technology and based on the Dongfanghong-4 Enhanced satellite platform. This new satellite is believed to have been a backup for ChinaSat-3A (中星3A), and will now complement its services. Like ChinaSat-3A, ChinaSat-3B is expected to provide communications, radio, and television transmission services.

Once commissioned in orbit, ChinaSat-3B will be handed over to China Satcom to begin providing services to customers across China and the Western Pacific. It will also join China Satcom’s extensive fleet of spacecraft.

The patch for the Long March 7A Y15 mission.

In their post-launch blog post, the China Academy of Launch Vehicle Technology shared that ChinaSat-3B was protected within a 4.2-meter diameter fairing during launch, the standard choice for communications satellite launches. Several optimizations to the rocket’s control systems and test process were said to have been implemented during the launch campaign. Additionally, the academy stated that more missions for the Long March 7A are planned for this year, with two having taken place so far. The China Aerospace Science and Technology Corporation and the Academy of Aerospace Liquid Propulsion Technology shared the same points.

Today’s mission was the 10th launch of a Long March 7A vehicle, the 19th launch of the Long March 7 series, and the 577th launch of the Long March launch vehicle series. This was also the 30th launch from China in 2025.

Liftoff videos via 追箭部落, SpaceLens云上天镜, China航天, 卡尔达瓦里希, 中国航天科技集团, and 空天逐梦 on Weibo, additional launch footage and live stream replay via International Rocket Launches on YouTube.

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Check out the previous Long March 7A launch

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What is the Long March 7A?

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

The Long March 7A is the new-generation workhorse for beyond low Earth orbit missions, and was developed by the China Academy of Launch Vehicle Technology. This vehicle utilizes a three-and-a-half-stage design and is fuelled by rocket-grade kerosene and liquid oxygen in its boosters, first, and second stages long with liquid hydrogen and liquid oxygen in the third-stage.

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

• 7,000 kilograms to geostationary transfer orbit

• 5,500 kilograms to a 700-kilometer sun-synchronous orbit

• 5,000 kilograms to a trans-lunar trajectory

The Long March 7A Y15 vehicle during rollout at the Wenchang Space Launch Site.

The Long March 7A's first stage is equipped with two YF-100 engines that produce 245 tons of thrust using rocket-grade kerosene and liquid oxygen, complemented by four boosters, each with a YF-100 engine generating 122 tons of thrust, resulting in a combined thrust of approximately 733 tons. The second stage is powered by four YF-115 engines, which together generate 72 tons of thrust using the same fuel combination. The third stage of the Long March 7A features two YF-75 engines, providing 17 tons of thrust by burning liquid hydrogen and liquid oxygen.

On the launchpad, the Long March 7A stands at 60.13 meters tall and weighs 573,000 kilograms when fully fuelled. The first and second-stage have a diameter of 3.35 meters, the four boosters are 2.25 meters in diameter, and the third-stage has a diameter of 3 meters, while the fairing has a diameter of 4.2 meters.

So far the Long March 7A has only flown from the Wenchang Space Launch Site, on the east coast of Hainan province.

The fairing, housing ChinaSat-3B, heading to the vehicle assembly building to be placed atop of the Long March 7A Y15 vehicle.

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