Apollo 11 launch as broadcast live by NASA on July 16, 1969

In a major shift, NASA is considering using two commercial launchers to send an unpiloted Orion crew capsule and its European-built service module on a test flight around the moon next year, maintaining the lunar test flight’s schedule despite fresh delays in the development of the multibillion-dollar Space Launch System that jeopardize the heavy-lifter’s 2020 inaugural flight, the agency’s administrator said in a congressional hearing Wednesday.

The Orion spacecraft slated to fly around the moon on an unpiloted mission next year has arrived back at the Kennedy Space Center following an environmental test campaign in Ohio, ready for a series of final checkouts before officials pause launch preparations this summer to await readiness of NASA’s Space Launch System.

Northrop Grumman’s Antares rocket will deliver a Cygnus supply ship into orbit Saturday to begin a two-day pursuit of the International Space Station.