Nasa is moving its huge Moon rocket, Artemis, back to the launch pad. This is the second time the rocket has made this journey. The goal is to send astronauts around the Moon, a feat not achieved in over 50 years.
The Space Launch System (SLS) and Orion spacecraft are 98 meters tall. They are traveling four miles from their assembly building to Pad 39B at the Kennedy Space Center in Florida.
Fixing a Helium Issue
Nasa had to stop a launch attempt in March because of a problem with the rocket's helium system. The vehicle was brought back indoors for repairs. Engineers say the issue is now fixed. They hope final tests at the pad will confirm the rocket is ready for an early April launch.
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Start Your News DetoxThe SLS came out of the Vehicle Assembly Building (VAB) after nightfall. The VAB is one of the world's largest buildings. The rocket then began its slow trip towards the Atlantic coast.
The rocket and its launch platform weigh about 5,000 tonnes. They are carried by Crawler-Transporter-2. This tank-like vehicle was built by Nasa in 1965 to move Saturn V Moon rockets.
The transporter moves at about one mile per hour (1.6 km/h). It goes even slower on turns and ramps. The four-mile journey can take up to 12 hours. This slow pace is deliberate to reduce stress on the multi-billion-dollar rocket. It also helps teams spot any movement of the mobile skyscraper.
Final Checks and Launch Window
Once the rocket is at the pad, engineers will spend several days checking the repairs. They will also make sure nothing shifted during the journey. They will reconnect the launch tower and run pressure tests on the helium system.
Controllers will also practice parts of the countdown. They will use the same computers and networks as on launch day, but without fueling the tanks.
After these tests, Nasa's mission management team will meet. This meeting will happen a few days before the earliest launch date of April 1. They will review the data and decide if the launch can proceed.
The Artemis II crew includes Reid Wiseman, Victor Glover, Christina Koch, and Jeremy Hansen. They have started pre-flight quarantine. They will travel to Florida closer to launch for rehearsals, including suiting up. Nasa is aiming for launch opportunities in the first week of April for the ten-day mission. This mission will loop around the far side of the Moon and then return to Earth.
The previous rollout in March was halted due to an interruption in helium flow to the upper stage. Helium is used to pressurize propellant tanks. A fault could affect the engine or fuel draining. Managers decided to return the SLS to the VAB for full access to the problem area.
Inside the VAB, work platforms were used to reach valves and plumbing in the helium circuit. Engineers replaced faulty parts and swapped batteries. They then re-tested to confirm the fault was cleared.
Nasa managers approved the second rollout after reviewing the data. If these new tests go well, Artemis II will be the first crewed mission in the program. This will prepare for Artemis III in Earth orbit in 2027, and Artemis IV in 2028, which aims to land astronauts on the Moon.
The first launch opportunity for Artemis II is 6:24 PM Eastern Daylight Time on April 1. Other launch windows are available on April 2, 3, 4, 5, and 6. If those are missed, there is a final opportunity in April on the 30th.
