On Tuesday China’s Long March 5B rocket successfully launched from Wenchang Satellite Launch Center on Hainan Island, which extends into the South China Sea. The rocket carried an uncrewed trial version of its next-generation spacecraft—with a mass of nearly 22 tons—successfully into orbit.

From there, the spacecraft will attempt to raise its orbit to about 8,000km and successfully return to Earth at a high velocity, This will provide data for China’s space program as it contemplates a deep space exploration plan.

This was just the fourth launch of the large Long March 5B rocket, which is nearly as powerful as United Launch Alliance’s Delta IV Heavy booster. After the second flight of this Chinese booster failed in July 2017, the rocket has successfully launched twice in the last six months, indicating it is back on track.