Live coverage: SpaceX launches more Starlink satellites on Falcon 9 rocket

SpaceX called off the planned launch of a Falcon 9 rocket Friday at Cape Canaveral, halting the countdown less than a minute before liftoff to allow time to perform additional ground system checkouts before the mission’s next launch opportunity no earlier than Sunday.

Keith Gendreau, an astrophysicist at NASA’s Goddard Space Flight Center, recently spoke with Spaceflight Now about a new experiment on the International Space Station to demonstrate X-ray communications in space for the first time.

Two satellites designed to beam radio and television broadcasts, Internet connectivity and other communications services across Russia have arrived at a launch pad at the Baikonur Cosmodrome in Kazakhstan for liftoff Thursday on the first flight of a Russian Proton rocket this year.