CAPE CANAVERAL, Fla. — The rocket that will launch the next humans to the moon is rolling to the pad for its historic mission, which could lift off just a few weeks from now.
NASA’s Space Launch System (SLS) rocket, built to support the agency’s Artemis 2 mission and usher in a new era of crewed flights to the moon, headed out from the Vehicle Assembly Building (VAB) here at Kennedy Space Center (KSC) in Florida this morning (Jan. 17), beginning a 4-mile (6.4 kilometers) trek to Launch Complex-39B (LC-39B).
SLS stands 322 feet (98 m) tall and weighs roughly 2,870 tons (2,600 metric tons) when fully fueled. The rocket is powered by two space shuttle-era solid rocket boosters (SRBs) stacked 177 feet (54 m) tall on either side and four RS-25 engines, also originally designed for the space shuttle. Combined, they produce 8.8 million pounds of thrust at liftoff to deliver the rocket’s upper stages and Orion crew capsule to space.
Moving slower than 1 mph (1.6 kph), the massive vehicle’s journey from the VAB to LC-39B is expected to take eight to 10 hours. Once it’s at the launch pad, NASA will spend the coming weeks performing systems integrations and vehicle checkouts ahead of a fueled launch countdown simulation known as a wet dress rehearsal, and, if all goes according to plan, a launch attempt in early February.
NASA is targeting Feb. 2 for the wet dress rehearsal. Feb. 6 is the earliest possible launch day for Artemis 2, which will fly NASA astronauts Reid Wiseman, Victor Glover and Christina Koch and Canadian Space Agency astronaut Jeremy Hansen aboard the Orion spacecraft on a roughly 10-day mission around the moon.
The launch date is largely dependent on how systems checks go once SLS reaches the pad, however, with backup launch opportunities mapped out through Feb. 11 and additional windows in March and April.
Artemis 2 is the second mission of NASA’s Artemis program and will be the first to fly a crew aboard Orion. Artemis 1 launched in November 2022, after a checkout campaign that ended up lasting most of the year. After its debut rollout in March 2022, the Artemis 1 SLS wet dress rehearsals and launch attempts were plagued by cryogenic hydrogen leaks, weather delays and other factors that resulted in three trips back to the VAB for maintenance.
NASA officials are hoping to avoid a similar campaign with Artemis 2 and voiced confidence in the rocket’s readiness and optimism about a launch in the February window.
When it launches, SLS will deliver Orion to Earth orbit, where the Artemis 2 crew will perform systems checks ahead of a translunar injection burn that puts them on course for the moon. That burn will be completed by SLS’ interim cryogenic propulsion stage, which Orion and its service module will detach from to conduct proximity maneuvering tests on their way to lunar space.
The Artemis 2 astronauts won’t go to lunar orbit. Instead, the mission will fly a “free-return trajectory” that loops the capsule around the moon and slingshots it back to Earth regardless of any anomalies the crew or spacecraft may encounter during the mission. The flight path ensures the safe return of the Artemis 2 crew and Orion, without the possibility of a malfunction stranding them in lunar orbit.
Artemis 2 is the next step in NASA’s goal to return astronauts to the lunar surface, where the agency hopes to establish a base in the moon’s south polar region. Artemis 3 will be the first mission designed for a lunar landing, but it will proceed only if Artemis 2 is successful.
Artemis 2 will be as much a proving ground of Orion’s life support systems as Artemis 1 was for the spacecraft’s core design. Any unexpected speed bumps during the upcoming mission may cause further delays for Artemis 3, the expected launch date for which is already beginning to slip past NASA’s hopeful 2027 target.
Artemis 2 crew members have been training at KSC, conducting launch-day rehearsals over the past several months in preparation for their mission, and were present to see their SLS rocket roll out for the first time today.