In the mission control room at the Wenchang commercial spaceport, the cheering started when camera feeds from the support vessels picked up the booster near the recovery ship. Once the net had hold of it, designers, engineers and ground controllers erupted.
That was Friday, and the story the engineers were celebrating was the debut flight of the Long March 10B, a large liquid-fueled rocket built by the China Academy of Launch Vehicle Technology, a Beijing-based subsidiary of China Aerospace Science and Technology Corp. State outlet China Daily reported that it was the first time China had recovered the main body of a carrier rocket, and the world’s first orbital-class recovery using a net of pretensioned cables.
What unfolded in the air
At 12:15 pm, seven engines burning liquid oxygen and kerosene lifted the 63.6-meter rocket off a service tower in Wenchang, a coastal city in Hainan province. About two and a half minutes later it reached the separation point, several kilometers above the Karman Line. The two stages parted and the first stage’s engines shut down for a time. On the second stage, one liquid oxygen-methane engine lit to drive the upper stage toward its target orbit, where it deployed a satellite.
The first stage kept climbing briefly on momentum. Its grid fins unfolded and the reaction control system adjusted its attitude. On the way down, select engines relit twice. Between those burns the booster leaned on a carefully calculated falling position, letting air resistance take off speed.
Waiting hundreds of kilometers southeast of Wenchang was the recovery ship Linghangzhe, tracking the booster and adjusting its own position. Rail-mounted sliders moved the cables at the ship’s center to improve the odds of a catch. In the final seconds, every engine on the stage cut off and metal hooks deployed to grab the cables.
Auxiliary cables then reached out from around the booster to steady it, and an automatic clamping platform slid beneath to clamp, lock and support it. The whole recovery, counted from stage separation, took about six minutes.
Why a net
Chen Muye, a structural designer of the rocket, said the method removed the need for landing legs. “It removed the need for complex landing legs, which helped reduce the rocket’s structural weight and, in turn, boosted its payload capacity and cost-effectiveness,” he said. He added that the system tolerates deviations in landing position and can suit rockets of different sizes.
Wang Wei, a project manager for the Long March 10 series, called the rocket a breakthrough in low-cost, high-payload reusable launch technology. He said it would mainly serve satellite constellation deployment in low-Earth orbit, and that the recovered booster is expected to fly again before the end of this year.
Fully fueled, the rocket weighs about 760 metric tons. It is 5 meters across, and more than 890 tons of thrust push it off the pad. It can carry 16 tons to a low-Earth orbit at 200 kilometers, or 11 tons to a 50-degree inclined orbit at 900 km. Two other Chinese rockets, LandSpace’s ZQ 3 and the Long March 12A, had tried recovery before and failed at the last moment. In February, the Long March 10A flew its first mission and its booster made a planned controlled splashdown in the South China Sea.
Wang Yanan, chief editor of Aerospace Knowledge magazine, said reusable rockets are seen by the Chinese space community as a strategic asset. “It is virtually impossible for companies to use conventional expendable rockets to compete with those that have reusable products,” he said.
