NASA’s next expeditions to the Moon took a step closer to reality when the Space Launch System (SLS) rocket passed its final dress rehearsal tests in late June.
The test program, called ‘wet dress rehearsal’, was conducted to test how the rocket and ground control systems work together, as well as train crews to proficiency in launch procedures. The test brings the rocket to the launchpad, fills and pressurizes the fuel and oxidizer tanks (hence the name ‘wet’ dress rehearsal’), activates all the electrical and hydraulic systems, and runs the launch countdown as if the rocket were going to launch. The countdown tests every system in the rocket and all ground launch control systems right down to the last 29 seconds before the engine start to see if everything (and everyone!) will operate as planned during an actual launch. The test stops at T-minus 29 seconds.
With the successful completion of this final ground test, the SLS rocket and Orion capsule now roll 3.4 miles back to the Vehicle Assembly Building (VAB) where they will be prepared for their first real mission as Artemis 1, a test flight to the moon. Currently planned for launch no earlier than late August, Artemis 1 will send the uncrewed Orion capsule on a month-long trip around the moon in preparation for a crewed circumlunar flight in 2024 and a crewed lunar landing possibly a year or two later.