The quartet is set to liftoff from Launch Complex 39A at NASA’s Kennedy Space Center on Thursday, July 31. Their Dragon spacecraft, Endeavour, will fly for a record-setting sixth time.

SpaceX will go for another first Thursday, this time flying a refurbished Dragon supply ship carrying nearly 6,000 pounds of cargo and experiments to the International Space Station nearly three years after its first mission.

A modified Russian missile built for nuclear war blasted off on a peaceful mission Friday, targeting placement of a European Earth observation satellite in orbit to measure atmospheric chemistry and global air quality. Liftoff from the Plesetsk Cosmodrome in northern Russia occurred at 0927 GMT (5:27 a.m. EDT).