With the launch of Artemis II a day away, humanity's return-to-the-moon project is approaching a crucial crossroads. This mission is the first flight toward the vicinity of the moon in 54 years since Apollo 17 in 1972.
According to the National Aeronautics and Space Administration (NASA), Artemis II is scheduled to launch from Launch Complex 39B at Kennedy Space Center in Florida at 6:24 p.m. on Apr. 1 Eastern time, which is 7:24 a.m. on the 2nd Korea time. The launch window is two hours, allowing liftoff at any point within that period if weather and technical conditions permit.
NASA is currently conducting final checks at the launch site and assesses an 80% chance that launch-day weather will be favorable. Launch opportunities remain open through the 6th (Eastern time), so the schedule could shift depending on weather or technical factors.
Earlier, NASA identified a liquid hydrogen leak on Artemis II in February this year and postponed the launch to March. An additional issue with helium flow in the upper stage then arose, pushing the target to April for further inspections and refurbishment.
◇ The goal is not a lunar landing but "crewed system verification"
The focus of this flight is not a lunar landing but validating technologies for crewed lunar landings and deep-space exploration. The crew consists of Commander Reid Wiseman, Pilot Victor Glover, astronaut Christina Koch, and astronaut Jeremy Hansen of the Canadian Space Agency (CSA). They will conduct the first test of the Space Launch System (SLS) heavy rocket and the crewed spacecraft Orion flying people to the vicinity of the moon.
The SLS rocket is a super-heavy launcher developed by NASA, leveraging engines and solid rocket booster technologies from the space shuttle program. At the top sits the Orion spacecraft carrying the astronauts. Orion consists of a crew module for human occupants and a service module that provides power and propulsion.
After liftoff, SLS reaches supersonic speed in about 56 seconds. Orion then separates from the rocket's upper stage (ICPS) about 3 hours 23 minutes later and begins proximity operations and manual piloting tests. The astronauts will use the ICPS as a target to bring Orion in close, fly around it, and assess handling performance.
For about 10 days, Orion will follow a "free-return trajectory" that uses the gravity of the moon and Earth to swing behind the moon and return to Earth. A free-return trajectory is designed to naturally set the spacecraft on a path back to Earth after looping around the moon without a major engine burn.
On the first day of the mission, in a high Earth elliptical orbit, the crew will check life-support systems such as the potable water supply, toilet, and carbon dioxide removal system. On the second day, they will execute a burn for translunar injection (TLI) to head toward the moon in earnest.
On day 6, Orion will approach to about 4,000–6,000 miles (about 6,400–9,600 kilometers) above the lunar surface to observe the far side of the moon. During this phase, there will be a 30–50 minute period of lost communications with Earth. In the return phase, the crew will test radiation sheltering procedures, manual control, and reentry preparations, then, if on schedule, splash down 9 days 1 hour 46 minutes after launch.
NASA expects the Artemis II crew to surpass the human farthest-distance record set by Apollo 13. Apollo 13 reached a point about 400,000 kilometers from Earth before returning. The Artemis II crew is anticipated to set a record beyond that.
◇ Korean CubeSat also aboard… what's next for lunar exploration
This mission also carries the small satellite K-RadCube, developed by the Korea Astronomy and Space Science Institute (KASI). After launch, K-RadCube will separate at an altitude of about 70,000 kilometers, enter an independent orbit, and measure space radiation intensity while passing through Earth's radiation belts, the Van Allen belts. The Van Allen belts are donut-shaped radiation regions encircling Earth that any crewed deep-space spacecraft must traverse.
The data obtained will be used to analyze how radiation in the Earth-to-moon transit corridor could affect astronauts.
Experiments will also assess the effects of the space radiation environment on semiconductors. Researchers will expose Samsung Electronics' next-generation semiconductor multi-chip modules and SK hynix's semiconductor memory chips to radiation and analyze resulting damage or errors.
NASA says this mission builds on the achievements of Artemis I, the uncrewed test flight in 2022, while laying the groundwork for future crewed lunar landings, long-duration stays, and Mars exploration. In other words, it is the first crewed gateway to testing a new lunar exploration architecture that includes international cooperation and commercial partnerships.
After the Artemis II launch, NASA plans a mission next year to re-test system performance near Earth, and in 2028 it aims to conduct a crewed exploration of the lunar south pole. NASA also plans to increase the frequency of lunar missions to about once a year and build a lunar base where astronauts can stay and conduct research.