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

A problem with a U.S. Air Force tracking radar kept a Falcon 9 rocket crowned with a NOAA space weather observatory grounded Sunday, forcing a long-delayed mission to stay on Earth an extra day.

Closing out a 27-hour pursuit after a predawn launch from Florida’s Space Coast, a SpaceX Crew Dragon capsule glided to an automated docking early Sunday at the International Space Station, accomplishing one of the ship’s key test objectives before astronauts take a ride later this year.

Watch a video replay of Monday night’s hotfire of a SpaceX Falcon 9 rocket at NASA’s Kennedy Space Center in Florida. The rocket is set for launch Thursday with Qatar’s Es’hail 2 communications satellite.