The first human spaceflight to the vicinity of the Moon since December 1972 is set to roll out to Launch Complex 39B at the Kennedy Space Center. The Orion spacecraft and its associated Space Launch System rocket, mounted on its mobile launch platform, is scheduled to roll out early on Saturday, Jan. 17.
This flight is only the second mission for SLS, and its first flight with crew. Artemis II’s four-person crew will fly the Orion spacecraft, which they named Integrity, on a 10-day mission to loop around the Moon and return to Earth, splashing down in the Pacific off the coast of California.
Integrity will not enter lunar orbit, but will nonetheless fly further than any other spacecraft with humans to date, going to a point roughly 7,500 km from the lunar far side.
Artemis II is commanded by former chief of NASA’s Astronaut Office Reid Wiseman, with Victor Glover acting as the pilot, while Christina Koch and Canada’s Jeremy Hansen are mission specialists. These four astronauts will be the first to fly on a human deep space mission since Apollo 17’s Gene Cernan, Harrison Schmitt, and Ron Evans.
The official Artemis II crew portrait. (Credit: NASA)
Koch will be the first woman, Glover the first person of color, and Hansen the first non-American to launch on a deep space mission as well. All three NASA astronauts on Artemis II are spaceflight veterans, each having served tours of duty on the International Space Station, while Jeremy Hansen is making his first space flight.
Saturday’s Artemis II rollout will be the first for a human mission to the Moon’s vicinity since the Apollo 17 Saturn V rolled out of the Vehicle Assembly Building (VAB) on Aug. 28, 1972 to Launch Complex 39A. Much of the Apollo program’s infrastructure is also used for Artemis missions; Launch Complex 39, the VAB, the Crawler Transporter-2 (CT-2), the launch control center, and the crawlerway were all developed and built during the Apollo program.
Artemis II will roll out of the VAB onto the nearly seven-kilometer-long crawlerway, lined with smooth river rock from quarries, to Launch Complex 39B (LC-39B) over the course of up to 12 hours. The rollout is scheduled for no earlier than 7:00 AM EST (12:00 UTC) on Saturday, with CT-2 rolling at a stately pace of less than one mile per hour.
Apollo 17 rolling out to the launch pad on Aug. 28, 1972. (Credit: NASA)
When the crawlerway was designed, it was realized that asphalt would not be suitable for holding the weight of the 6.65 million pound crawler-transporter, let alone the weight of the Launch Umbilical Tower and Saturn V on top of that.
The river rock acts as “ball bearings” and absorb energy when they are compacted. The CT-2 and Mobile Launcher 1 (ML1) with SLS combined weighs roughly 15 million pounds, and CT-2 is the only crawler modified to handle that weight. This is much heavier than the combined crawler-transporter, mobile platform, and rocket for the Saturn V (11 million pounds) and the Space Shuttle (12 million pounds)
Once CT-2, ML1, and the Artemis II SLS rocket combination reach the perimeter of LC-39B, CT-2 will begin leveling the ML/SLS combination as it slowly climbs the slope from the crawlerway to the 450-foot long flame trench underneath the center of the launch pad.
ML-2, the heaviest self-powered vehicle on Earth, is seen prior to rolling out Artemis II. (Credit: Max Evans for NSF)
ML1 and Artemis II will be jacked down onto the pad, which was redesigned as a “clean pad” at the end of the Space Shuttle program with three lightning towers but no permanent large above-ground towers. Workers will connect ML1 to the pad infrastructure, while CT-2 prepares to roll back empty.
A wet dress rehearsal will occur before the launch, currently scheduled for Friday, Feb. 6, at 9:41 PM EST (02:41 UTC Saturday, Feb. 7). This rehearsal will involve a complete countdown and propellant load similar to a launch, and NASA hopes to conduct some tests they were not able to during the Artemis I flow. However, meeting this launch date depends on the outcome of the wet dress rehearsal as well as resolving any other issues that come up during flight preparations.
As an example of what can happen during launch processing, Artemis I rolled out four times over eight months before finally flying on Nov. 16, 2022, after initially crawling out of the VAB on March 17 for a spring launch. Ground system issues, hydrogen leaks, sensors, a check valve, and tropical storm activity conspired to scrub wet dress rehearsals and launch attempts, forcing repeated rollbacks to the VAB.
The Artemis I SLS during its successful Green Run test on March 18, 2021. (Credit: Brady Kenniston for NSF)
Prior to its first rollout, Artemis I’s core stage also underwent “green run” testing at the Stennis Space Center in Mississippi, with two attempts needed before a successful test in March 2021. This green run was a full duration firing of the stage’s four Shuttle-derived RS-25 main engines; the Artemis II stage was not tested in this manner. The upcoming wet dress rehearsal could find new issues for the stage that need to be fixed.
Artemis II’s flight processing does have improvements over Artemis I. The SLS needs to have its flight termination devices installed before rollout to the pad; for Artemis I any issues with the termination system could have required a rollback to the VAB as the explosives were not accessible from ML1 at LC-39B. However, for Artemis II, there is now a modification that allows access to the flight termination system without returning to the VAB.
The ML1 launch tower required extensive repairs after Artemis I due to damage from the RS-25 and SRB sound waves and exhaust; elevator doors, pneumatic lines, seals, and cabling were destroyed. These repairs are complete, and the tower was reinforced and upgraded. Crews also installed a slide wire emergency egress system for the astronauts to use if a rocket or system malfunction threatens their safety at the pad.
Artemis II will be flying a 10-day mission that will pass by the Moon before returning to Earth. (Credit: L3Harris)
Once Artemis II passes its wet dress rehearsal and is ready for launch, the mission’s launch opportunities are constrained by factors ranging from solar power requirements to facility consumables supply. Artemis II has a few days each month from February to April available for flying, due to the lunar cycle.
Prior to Artemis II, LC-39B hosted one Apollo launch — Apollo 10 — as well as all three Skylab launches with the Saturn 1B, the Apollo-Soyuz Test Project, 53 Space Shuttle launches, Ares I-X, and Artemis I. Artemis II will be the 61st launch from LC-39B, which will host all Artemis missions launched on SLS. LC-39A, located next door, is leased by SpaceX.
The first crewed lunar flight since 1972 will be historic, and a successful flight would pave the way for Artemis III — the first crewed lunar landing in over half a century.
(Lead image: Artemis II prior to rollout, with logos to celebrate America’s 250th birthday this year. Credit: NASA)
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