Four space station crewmates boarded their Crew Dragon ferry ship Wednesday and undocked kick off an expedited return to Earth on Thursday, cutting their mission short because of an undisclosed medical issue.Crew 11 commander Zena Cardman, co-pilot Mike Fincke, Japanese astronaut Kimiya Yui and Russian cosmonaut Oleg Platonov bid farewell to three crew members staying behind and floated into their Crew Dragon capsule, closing the ferry’s hatch at 3:29 p.m. ET on Wednesday.The Crew Dragon capsule carrying Crew 11 commander Zena Cardman, co-pilot Mike Fincke, Japanese astronaut Kimiya Yui and Russian cosmonaut Oleg Platonov backs away from the International Space Station, kicking off a 10-hour flight back to Earth. / Credit: NASA”What an adventure we’ve had together,” Fincke radioed. “I think what I’m going to remember most is the camaraderie we’ve had across the planet that’s really symbolic of 25 years of continuous habitation aboard the space station. I’m glad we can all work together in space.”AdvertisementAdvertisementAdvertisementAdvertisementLeft to operate the International Space Station are Soyuz 28 commander Sergey Kud-Sverchkov and his two crewmates, cosmonaut Sergey Mikaev and NASA astronaut Chris Williams.Addressing her Expedition 74 crewmates, Cardman said she knows the space station is in good hands. She told ground controllers: “Your International Space Station is a testament to the power of cooperation, and it’s been an absolute privilege to take part in this endeavor … Crew 11 is coming home.”After completing final preparations, the Crew Dragon undocked and slowly backed away from the space-facing port of the station’s Harmony module at 5:20 p.m. Wednesday.If all goes as planned, the capsule’s braking rockets will fire for 13 minutes and 15 seconds starting at 2:51 a.m. Thursday. The rockets will slow the ship by about 196 mph, just enough to drop the far side of the orbit into the atmosphere on the planned reentry trajectory. After a northwest-to-southeast plunge across the Pacific Ocean, the crew is expected to splash down off the coast of Southern California at 3:41 a.m., closing out a 167-day stay in space.A camera aboard the Crew Dragon looks over the sho …