A replay of the United Launch Alliance Atlas 5 rocket launching Mexico’s Morelos 3 communications satellite from Cape Canaveral, Florida.

With the Atlas 5 rocket that will boost it into space now assembled and waiting, a $408 million NASA communications satellite is in final preparations for its science data relay mission.

A second unpiloted test flight of Boeing’s Starliner crew capsule — ordered after an initial demonstration mission fell short of reaching the International Space Station — is now scheduled for launch from Cape Canaveral in August or September, leaving little margin to conduct the spaceship’s first flight with astronauts before the end of the year.