The SLS Core Stage ignites, beginning a nominal full-duration hot-fire test on March 18, 2021. [credit:
Trevor Mahlmann / Ars Technica
It has been a long, difficult, and expensive road for NASA and its Space Launch System rocket. But on Thursday afternoon, the space agency got to taste some success with what appeared to be a nominal ground test-firing of the vehicle’s core stage.
With brilliant spring sunshine blazing overhead, the four space shuttle main engines that power the rocket roared to life on a test stand in Mississippi. Then they burned for 499.6 seconds, exhausting the vehicle’s supply of liquid oxygen.
At about one minute into the test, the engines began rocking and rolling. Known as gimbaling, this process is what allows a rocket to change the direction of thrust in flight. This dynamic exercise lasted for about 30 seconds and appeared to proceed nominally as well.