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

SpaceX called off a planned launch attempt Saturday to deploy the next batch of satellites for the Starlink broadband network. Two commercial Earth-observing satellites for BlackSky are also awaiting a ride into orbit on the Falcon 9 rocket from pad 39A at the Kennedy Space Center in Florida.

NASA is modifying plans to send astronauts back to the moon in 2024 by taking the Gateway — a mini-space station to be assembled in lunar orbit — out of the critical path in favor of a simplified architecture, according to the agency’s chief of human spaceflight.

SpaceX teams working at Vandenberg Air Force Base in California were finalizing preparations Tuesday ahead of the launch of a Falcon 9 rocket Wednesday carrying a trio of Canadian-built radar observation satellites into orbit.