The next steps to take humanity back to the Moon are now on show for everyone to see. In the late hours of yesterday, NASA's Space Launch System (SLS) – the world's most powerful rocket – was rolled out across the 6-kilometer path between the Vehicle Assembly Building and the historic Launch Pad 39B, from which Apollo 10, Skylab, and 53 Space Shuttle launched. It took almost 11 hours to move the huge rocket. 

The SLS rollout is a crucial step in preparation for Artemis I, the uncrewed mission that will test the rocket and the Orion capsule, which within this decade will bring humans, including the first woman and the first person of color, back to the surface of the Moon. For now, SLS will next experience a wet dress rehearsal.  

Wet is the keyword there. In April, the rocket, which weighs a whopping 2.6 million kilogram (5.75 million pounds) when fuelled, will receive almost 3.2 million liters (700,000 gallons) of cryogenic propellant and will be tested as if it was about to launch. The test will be conducted as a scrub, the name for an aborted launch, with the countdown going down to 10 seconds before lift-off.

Given how much is riding on this, not just figuratively but also literally, everything has to be tested and rested. After the wet dress rehearsal is concluded, the rocket will go back to the Vehicle Assembly Building on the same crawler that has taken many missions to those same launchpads. 

The crawler will carry the rocket back into the Vehicle Assembly Building, where the rocket will be once again connected to the surrounding area through the extendable platforms. Scientists and engineers will access the rocket and remove the sensors placed there to monitor the rocket’s wet dress rehearsal. They will also charge the batteries of all the systems, including the Orion capsule, as well as add more cargo, and carry out final checks.

The rocket will be rolled back down to the launchpad a week before Artemis I is set to launch, currently no earlier than May.

Artemis I will be the maiden flight for the Orion capsule, which will travel for 25.6 days between Earth and the Moon, including spending six days in retrograde orbit around our natural satellite. If this test flight is successful, the first deep-space human flight in decades won’t be far behind. Artemis II is currently scheduled to launch in May 2024.