The launch of a Japanese H-2A rocket with the Emirates Mars Mission, a Mars orbiter developed in partnership between Emirati and U.S. scientists, was delayed Tuesday due to poor weather at the H-2A’s launch site on Tanegashima Island in southern Japan. Officials later announced that liftoff would not occur Thursday, again citing bad weather at the launch site. A new launch attempt is scheduled for Sunday, weather permitting.

Two American astronauts and one Russian cosmonaut boarded their Soyuz MS-06 landing craft for a homecoming Tuesday night, U.S. time, concluding 168 days in orbit. The trio undocked from the International Space Station at 5:08 p.m. EST (2208 GMT), and landed on the snowy steppe of Kazakhstan at 9:31 p.m. EST (0231 GMT Wednesday).

Flying on its 40th mission, a Japanese H-2A rocket lifted off at 0408 GMT (12:08 a.m. EDT) Monday from the Tanegashima Space Center carrying Japan’s GOSAT 2 satellite to measure greenhouse gases in Earth’s atmosphere and the KhalifaSat Earth observation satellite for the United Arab Emirates.