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

The launch was the first of about half a dozen missions planned to expand the National Reconnaissance Office’s proliferated architecture satellite constellation. Liftoff from pad 4 East at Vandenberg Space Force Base happened at 7:53 p.m. PST (10:53 p.m. EST, 0353 UTC).

SpaceX carried the Israeli-owned Amos 17 communications satellite from Cape Canaveral into orbit Tuesday on top of a Falcon 9 launcher, nearly three years after a SpaceX rocket explosion destroyed a predecessor payload before it could get off the ground.

SpaceX scrubbed a launch attempt early Wednesday at Cape Canaveral due to thick cloud cover, then delayed the liftoff of a Falcon 9 rocket with an Airbus-built communications satellite for Arabsat until Friday night to wait for improved weather and to make room for the test-firing of United Launch Alliance’s Vulcan rocket at a neighboring launch pad.