Photos: Atlas 5 rocket soars from West Coast

SpaceX test-fired 27 main engines on a Falcon Heavy rocket Thursday in Florida, clearing a hurdle before installing three commercial communications satellites on the launcher for a mission to geostationary orbit later this month.

SpaceX’s launch director halted a countdown Tuesday to replace a sensor on the upper stage of a Falcon 9 rocket set to blast off with the GovSat 1 communications craft, the product of a joint venture between the commercial satellite operator SES and the government of Luxembourg.

The 20th flight of a Rocket Lab Electron launcher appeared to run into trouble a few minutes after liftoff at 7:11 a.m. EDT (1111 GMT) Saturday from New Zealand, when video showed the rocket’s upper stage tumbling and shutting off its engine prematurely. The rocket was carrying two commercial BlackSky Earth observation satellites into orbit.