SpaceX test-fired one of their recovered boosters at their Hawthorne, TX test facility. Although it was tied down and didn’t go anywhere, they took it through a full-duration burn, as if it were actually carrying something up on the first leg of an orbital journey. And it’s so cool to see something so scorched and battle-scarred roaring to life again!
This particular stage will never fly again. This one was used on the JCAT 14 launch, and was determined to have hit a little too hard for them to be comfortable with its structural integrity. But the engines are still good, so they’re using those to validate the reusability of the Merlin engines prior to actually reusing them. Here’s what it looked the last time it underwent a full duration burn, almost three months ago: