Photos: Atlas 5 rolls out for launch

A critical test firing Saturday of the four main engines powering the first stage of NASA’s gargantuan Space Launch System moon rocket is the final major hurdle before the fully assembled booster’s costly, oft-delayed launch late this year on an unpiloted test flight.

The first satellite in a new class of ultra-powerful communications satellites for Intelsat lifted off Wednesday aboard the first Ariane 5 flight of the year. Launch from French Guiana occurred at 2320 GMT (6:20 p.m. EST).

United Launch Alliance called off a launch attempt Monday after hitting a snag during preparations to fill an Atlas 5 rocket with cryogenic propellants at Cape Canaveral, delaying the liftoff of a new U.S. Space Force infrared surveillance satellite until no earlier than Tuesday.