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

A Chinese Long March 3B rocket lifted off Tuesday from the country’s Xichang space base, heading into orbit with a secretive payload believed by Western observers to be a military communications satellite.

The mission is the first that will populate the 13th group of Starlink satellites in SpaceX’s megaconstellation. Liftoff from pad 39A at NASA’s Kennedy Space Center happened at 12:24 a.m. EST (0524 UTC).

The rocket launched more than 340 times successively and successfully before it encountered an issue with its upper stage on July 11. Liftoff of the Starlink 10-9 mission happened at 1:45 a.m. EDT (0545 UTC).