Live coverage: Soyuz crew arrives at International Space Station

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.

Flight controllers at NASA’s mission control center in Houston have completed the robotic swap out of a failed power distribution unit outside the International Space Station, clearing a hurdle ahead of Friday’s predawn launch from Cape Canaveral of a SpaceX supply ship.

A SpaceX Falcon 9 rocket climbed into space Monday from NASA’s Kennedy Space Center atop a column of gleaming exhaust, shooting a commercial resupply vessel toward the International Space Station with research projects looking into cosmic rays, the origin of Parkinson’s disease, the utility of small satellites and an experimental radiation-tolerant supercomputer.