Shenzhou 10, China’s longest human mission to date, ended safely early Wednesday with a landing on a Mongolian steppe.

Touchdown of the mission’s return capsule with its crew of two men and a woman came at 8:07 a.m. local time (8:07 p.m. Tuesday EDT), 15 days after it was launched from the Jiuquan launch site on a Long March 2F rocket.

Astronauts Nie Haisheng, Zhang Xiaoguang and Wang Yaping emerged smiling and apparently healthy from the lander. Nie, the mission commander, was ending his second spaceflight. Wang is China’s second female astronaut, as the China Manned Space Engineering Office refers to members of its flight crews.

Zhang Youxia, commander of China’s military-led human spaceflight program, termed Shenzhou 10 a “complete success.” During the crew’s 12-day visit to the Tiangong I docking target in orbit, they conducted life sciences experiments, lectured students on the ground and flew two additional docking maneuvers, one manual and one automated.

“With a complete success of this spaceflight mission as a milestone, China’s manned space program will enter into a new phase of manned space station construction,” Wang Zhaoyao, director general of the China Manned Space Agency, told reporters after the landing. “As we celebrate our success, we also realize the fact that there is still a gap between China and the leading countries in terms of manned space technology and capability. Much remains to be done for us to live up to the state’s needs and our people’s expectations. We still have a long way to go to fulfill the goals of our manned space program’s “three-step strategy.”

That strategy is to culminate with utilization of a small space station in 2020, with the first module apparently scheduled for launch as early as 2015. Also in the works is an autonomous resupply vehicle based on Tiangong I. During the mission, Chinese space officials declared the Shenzhou crew vehicle “operational” for the first time.