China has launched its top-secret military spaceplane for a third time, days after the US military’s winged spacecraft was grounded for several weeks due to problems with its SpaceX rocket.

Observers believe China’s spaceplane looks much like the US military’s X-37B, a reusable craft that Pentagon officials are similarly tight-lipped about. But there’s a distinction in that US officials will publicly discuss, at least in broad terms, the purpose of the X-37B and release images of the spacecraft.

The US military has two X-37Bs in its inventory, each with a cargo bay that could fit a large refrigerator. They resemble small space shuttles, with dimensions about one-quarter those of NASA’s retired shuttle orbiters. The X-37B spaceplanes have flown in space six times, logging missions as long as two-and-a-half years, thanks to deployable solar panels that generate power for greater endurance.