Boeing said Tuesday it is “making excellent progress” toward launching a second unpiloted test flight of its Starliner crew capsule to the International Space Station by the end of this year or in early January, setting the stage for the first Starliner demonstration mission with astronauts in mid-2021.

Three space station crew members — two short timers completing a 10-day flight and a veteran cosmonaut who has logged a world record 879 days aloft over five missions — undocked from the International Space Station and returned to Earth Friday, landing safely on the steppe of Kazakhstan to close out a problem-free flight.

A commercial Dragon supply ship loaded with genetically-enhanced mice, a beer brewing experiment, a CubeSat developed by Mexican students and other scientific research payloads arrived at the International Space Station Sunday.