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

A Chinese Long March 3B rocket launched a satellite Tuesday toward a position in geostationary orbit more than 22,000 miles above Earth. Chinese state media claimed the mysterious spacecraft has a communication and television broadcast mission, but analysts believe it could enter service for the Chinese military.

Hours after calling off a launch of a different rocket from a nearby launch pad, SpaceX’s launch team loaded a Falcon 9 rocket with propellant Saturday and fired its nine main engines on pad 40 at Cape Canaveral Air Force Station, setting the stage for a liftoff with a South Korean military satellite as soon as Tuesday amid a busy stretch of missions for the California-based rocket company.

Northrop Grumman’s launch team aborted an Antares rocket launch from Virginia’s Eastern Shore minutes before liftoff Sunday evening. The rocket is set to loft a Cygnus cargo freighter toward the International Space Station with nearly four tons of supplies and experiments.