Photos: Gallery of Delta 2 launch

SpaceX test-fired a Falcon 9 rocket Saturday at Cape Canaveral, a critical test before liftoff Wednesday with several tons of cargo heading to the International Space Station.

A Russian-built satellite hosting an array of X-ray telescopes is awaiting launch Friday from the Baikonur Cosmodrome in Kazakhstan on a mission to measure the mass and distance of colossal clusters of galaxies throughout the universe.

Fresh off a series of three complex spacewalks to repair a $2 billion cosmic ray detector, the International Space Station’s crew is set to receive two robotic resupply freighters in the next week after launches from Florida’s Space Coast and the steppes of Kazakhstan.