Live coverage: Kennedy Space Center to reopen Friday

Kathy Lueders, NASA’s newly appointed head of human spaceflight operations, said Thursday that without a crystal ball, she could not give a yes-or-no answer when asked whether she believes NASA can put astronauts back on the moon by the end of 2024 as called for by the Trump administration.

SpaceX test-fired the Falcon 9 rocket early Saturday ahead of launch with the next four astronauts heading to the International Space Station. The static fire test before sunrise Saturday in Florida was a major step toward liftoff Thursday.

A NASA spacecraft that will fly closer to the sun than any mission before will launch on a Delta 4-Heavy rocket in 2018, requiring a boost from the largest active launcher in the U.S. inventory and repeated flybys around Venus to reach an operating post inside the solar atmosphere.