Video: Orion launch replays

The mobile service tower is retracted from the Delta 4-Heavy rocket and Orion spacecraft for Exploration Flight Test 1.

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.

NASA announced Monday it will order at least six reusable Orion crew capsules from Lockheed Martin for $4.6 billion to fly astronauts to the vicinity of the moon in the 2020s, and the agency said it plans to purchase hardware for up to 12 Orion vehicles by 2030.