Video: Former shuttle engine test-fired

NASA is moving forward with a crucial test-firing of the core stage of the first Space Launch System heavy-lift rocket as soon as Jan. 17 after engineers were satisfied with the results of a fueling test last month.

A troublesome liquid oxygen valve on the Space Launch System’s first flight-rated core stage will keep NASA from performing a second test-firing of the rocket’s four main engines this week.

The four RS-25 engines at the bottom of NASA’s first Space Launch System core stage shut down about a minute into a ground test-firing Saturday that was supposed to last more than eight minutes.