Q&A with Keith Gendreau, principal investigator of the first X-ray space communications experiment (members only)

Another batch of 52 Starlink satellites launched late Tuesday from Vandenberg Space Force Base in California, on the way to join SpaceX’s fleet of more than 4,000 spacecraft beaming broadband signals around the world.

SpaceX test-fired a Falcon 9 rocket for the second time Saturday after replacing a valve following an earlier static fire test Wednesday. The move has postponed the Falcon 9 rocket’s launch with the Amos 17 commercial communications satellite to no earlier than Tuesday.

A Soyuz rocket carrying a military spy satellite for the United Arab Emirates lifted off from French Guiana at 8:33 p.m. EST Tuesday (0133 GMT Wednesday). A launch attempt Sunday night was scrubbed due to the risk of lightning, and a countdown Monday was called off due to a telemetry issue associated with the range safety system at the Guiana Space Center.