As NASA’s Space Launch System (SLS) rocket stands ready for its first test flight next week, the Artemis program prepares to follow in the footsteps of Apollo, which first carried humans to the Moon ...

You test your engines while you develop them, but once they are production ready, you don't need to test them that much. But keeping the lights on means doing maintenance of the stands, tanks, etc.

NASA/MSFC has a requirement for an Interim Cryogenic Propulsion Stage (ICPS) for the early Space Launch System (SLS) missions. The early flights of the SLS architecture will require the use of an ICPS ...