A Pakistani astronaut will become the first foreign national aboard China’s Tiangong space station, as Beijing steps up space diplomacy amid a burgeoning battle with the United States for supremacy in orbit.

NASA astronaut Don Pettit and Roscosmos cosmonauts Alexey Ovchinin and Ivan Vagner successfully departed the International Space Station for their return voyage to Earth.

A spaceship carrying three astronauts docked Thursday with China’s space station in the latest crew rotation, marking a further step in the country’s ambitions for a crewed mission to the moon and explore Mars.