Q&A with Mark Mulqueen, Boeing’s space station program manager

Concern about a possible ammonia coolant leak Wednesday prompted astronauts on the International Space Station to evacuate the U.S. segment of the complex and shelter in the Russian portion of the outpost while flight controllers scrambled to untangle initially confusing telemetry.

Five months after a frightening launch abort, cosmonaut Alexey Ovchinin and NASA flight engineer Tyler “Nick” Hague, along with first time flier Christina Koch, are set for liftoff Thursday on a six-hour flight to the International Space Station, boosting the lab’s crew back to six.

SpaceX trucked its Crew Dragon Endeavour spacecraft — refurbished with a new heat shield and structural enhancements — across the Cape Canaveral spaceport this week for attachment to a Falcon 9 rocket ahead of a planned liftoff next Thursday with four astronauts heading to the International Space Station.