There were no weather problems or technical issues as liftoff approached.
NASA and its partners have the same launch window today as Thursday. They must go by 6:44 a.m. PST.
The space agency couldn't launch the spacecraft from Cape Canaveral Air Station on Thursday because of problems with a ship that wandered into restricted wars near the launch pad, wind gusts and stuck fuel valves.
The 4 1/2 hour, unmanned mission is meant to test America's newest spacecraft — one that's being designed to take astronauts to the moon, asteroids, Mars and beyond in coming decades.
After launch, Orion is set to orbit Earth twice, swinging out to 3,600 miles, farther than any spacecraft designed to carry humans has ventured beyond Earth since Apollo went to the moon. Splash down is expected in the Pacific Ocean about 600 miles west of Baja California, Mexico.
Engineers hope the test flight will tell them a lot about how the spacecraft will perform in deep space and as it hurtles back to the Earth at 20,000 mph.