âWe had a successful initiation of the enginesâ: NASA test-fires its first SLS mega-rocket Stennis Space Center conducted its final hot fire test in the Green Run test series on NASAâs new Space Launch System core stage. Stennis Space Center conducted its final hot fire test in the Green Run test series on NASAâs new Space Launch System core stage. While the rocketâs engines were shutdown before the anticipated 8 minute time frame they said it was a âsuccessful initiation of the engines.â (Source: NASA) By Lindsay Knowles | January 14, 2021 at 9:14 AM CST - Updated January 17 at 6:28 AM HANCOCK COUNTY, Miss. (WLOX) - Stennis Space Center conducted its final hot fire test in the Green Run test series on NASAâs new Space Launch System core stage Saturday afternoon. While the rocketâs engines were shut down before the anticipated eight-minute time frame, NASA officials said it was a âsuccessful initiation of the engines.â