For years, NASA has been working on their massive Space Launch System (SLS), a next-generation heavy lift rocket that could launch cargo and astronauts beyond low-Earth orbit for the first time since the Apollo Program. They’ve been developing it in tandem with Orion, a crew capsule that would carry those astronauts into Earth orbit and beyond.

Orion’s next big test flight, called EM-1, an uncrewed mission into lunar orbit, is currently scheduled for June 2020. But in a Senate committee h