Live coverage: International Space Station crew lands in Kazakhstan

An Atlas 5 rocket successfully launched another Cygnus cargo freighter for Orbital ATK Tuesday night, fulfilling the booster’s role of reestablishing America’s resupply link to the International Space Station.

A huge U.S.-built, Canadian-owned communications satellite weighing 15,600 pounds, the heaviest spacecraft of its kind ever launched, is mounted to a Falcon 9 rocket for liftoff early Sunday from Cape Canaveral on a heavy-lifting mission that previously would have required SpaceX to throw away the launcher’s first stage booster.

The launch of NASA’s Mars 2020 rover is less than a year away, and the steady pace of work inside the craft’s pristine assembly hall in California is keeping the mission on schedule for liftoff from Cape Canaveral next July, despite growing costs, according to mission managers.