Live coverage: 400th Proton rocket takes off with Russian satellite

Seven Japanese and Vietnamese smallsats are set to ride Japan’s solid-fueled Epsilon launcher into orbit at 0050 GMT Friday (7:50 p.m. EST Thursday) on a mission that engineers say will demonstrate the light-class rocket’s ability to accommodate multiple payloads on a single flight.

Astra was gearing up for the first orbital test flight of its small satellite launcher, named Rocket 3.0, from Alaska on Monday, but officials scrubbed the launch after detecting a problem with a guidance, navigation and control system in the final minute of the countdown. Poor weather at the launch site also prevented liftoff over the weekend on the first of two missions under the auspices of DARPA’s Launch Challenge.

SpaceX has launched its third Falcon 9 of the year. The rocket is carrying a pair of communications payloads for Eutelsat and Asia Broadcast Satellite.