The first reflown Falcon 9 core is on the pad at LC-39A, and has completed a hotfire test. Due to the test having slipped to today, launch is now targeted for Thursday. Payload was not installed on the rocket for this test; the rocket will be brought down and back to the assembly building for attachment of SES-10 payload before being rolled back to the pad later this week.
If that was exciting, here’s another hotfire test for you, this time of an RS-25 engine in the venerable A-1 test stand, originally built to test Saturn S-II stages. This engine design will also be making reflights, but that’s less surprising, as the RS-25 is better known as the Space Shuttle Main Engine. This particular test, performed late last week at Stennis, was to validate a new engine controller. The engine used for this test was Engine No. 0528. It has never been to space; it’s a ground test article. Although designed as the world’s first fully reusable liquid rocket engine for first stage ascent, the SLS program is expected to exhaust the entire supply of RS-25s.