WENCHANG, July 10 — The Long March 10B, China’s latest medium-lift workhorse, has now been in service for just over two years, following a maiden flight that went off without a hitch on June 23, 2024. The rocket is a two-stage vehicle measuring 62 meters in length, with a diameter of 3.8 meters. Its first stage relies on four YF-100K engines burning kerosene and liquid oxygen, each generating 1,200 kilonewtons of thrust at sea level, for a combined first-stage thrust of 4,800 kilonewtons.
The second stage uses two YF-115 engines, each producing 180 kilonewtons. Payload capacity is 14 metric tons to low Earth orbit and 8 metric tons to geostationary transfer orbit.
For all the noise surrounding China’s heavy-lift ambitions, the salient point here is that the 10B fills a specific niche: a reliable, moderately sized launcher capable of handling communications satellites and other mid-range payloads without requiring the full power of the Long March 5 family. The inaugural flight lifted off from the Wenchang Space Launch Site, located at 19.6°N, 110.9°E, at 10:30 a.m. Beijing time, or 02:30 UTC.
The first stage separated at an altitude of 80 kilometers and then performed a boost-back burn, followed by an entry burn and a landing burn. It touched down on the drone ship ‘Haiyang 1’ at 10:45 a.m. Beijing time, 200 kilometers southeast of the launch site in the South China Sea.
The entire flight, from launch to landing, lasted 15 minutes. The rocket carried a test payload of a 5,000-kilogram communications satellite simulator, which it placed into a 400-kilometer low Earth orbit. That was, notably, the only payload on that first mission — a deliberate choice, it would seem, to validate the vehicle’s performance under representative mass conditions before committing to operational launches.
Since that June 2024 debut, the Long March 10B has been integrated into China’s broader launch manifest, though specific mission manifests beyond the first flight have not been detailed in public sources. The vehicle was developed by the China Academy of Launch Vehicle Technology, the primary state-owned designer of the Long March series. The YF-100K engines on the first stage represent a mature design, having been used in various configurations on earlier Long March models.
The kerosene-liquid oxygen propellant combination is standard for modern Chinese launch vehicles, offering a balance of specific impulse and handling safety. The 1,200-kilonewton sea-level thrust per engine places the YF-100K in the same class as the Russian RD-180, though the Chinese engine uses a staged-combustion cycle rather than the RD-180’s oxidizer-rich design.
The 14-metric-ton LEO capacity positions the Long March 10B between the smaller Long March 6 and the larger Long March 5 in China’s launcher lineup. For geostationary transfer orbit missions, the 8-metric-ton payload is sufficient for most modern communications satellites, which typically weigh between 4 and 6 metric tons at launch. The first-stage landing on ‘Haiyang 1’ marked a significant step for China’s space program.
While the country had previously demonstrated controlled reentry and landing with suborbital test vehicles, the Long March 10B’s first flight was the first time a Chinese orbital-class rocket stage had successfully landed on a drone ship at sea. The boost-back, entry, and landing burns were all executed autonomously, with the drone ship positioned 200 kilometers southeast of the launch site.
The 15-minute flight duration from liftoff to landing underscores the rapidity of the first-stage return profile. By comparison, SpaceX’s Falcon 9 first stage typically takes about eight to nine minutes from launch to landing on a drone ship, though the Falcon 9’s first stage separates at a lower altitude and velocity than the Long March 10B’s. With the Long March 10B now operational, attention will likely turn to the vehicle’s launch cadence and whether China will pursue further reuse of the first stage.
The successful landing on ‘Haiyang 1’ suggests the hardware is capable of multiple flights, but no official announcements have been made about refurbishment timelines or cost savings. The rocket’s medium-lift capacity also raises questions about its role in China’s planned space station resupply missions. The Tianzhou cargo spacecraft, which services the Tiangong space station, has a launch mass of around 13.5 metric tons — within the Long March 10B’s LEO capacity.
Whether the vehicle will be assigned to station logistics or remain focused on commercial satellite launches remains to be seen. For now, the Long March 10B stands as a capable addition to China’s launch fleet, one that demonstrated its core competencies on a single, clean flight in June 2024.
The next few years will show whether it becomes a regular sight over the South China Sea.
