Cosmonauts Zhang Lu, Wu Fei, and Zhang Hongzhang arrived at the Tiangong station in the Shenzhou-21 spacecraft. The previous crew's spacecraft, the Shenzhou-20, was damaged, so the Shenzhou-20 crew returned to Earth in the Shenzhou-21 spacecraft. To return the Shenzhou-21 crew to the Tiangong station, the uncrewed Shenzhou-22 spacecraft was sent.