For the first time in more than 50 years, astronauts are heading to the moon. The Artemis II crew launched Wednesday atop NASA’s SLS rocket, leaving thick vapor trails across a clear Florida sky. The four astronauts and teams on the ground are now preparing for the roughly 10-day mission ahead.
NASA astronauts Reid Wiseman, Victor Glover and Christina Koch, along with Canadian Space Agency astronaut Jeremy Hansen, rode an Orion capsule attached to the SLS rocket. The historic flight will carry them on a roughly 230,000-mile trip around the moon and back, serving as a critical crewed test of the Orion spacecraft.
The mission will test life-support systems, maneuvering and other spacecraft functions while also conducting science that will inform future deep-space and lunar-surface missions.
The trajectory
Artemis II follows a free return trajectory that keeps the spacecraft primarily under Earth’s gravitational influence, swings it past the moon, and lets it fall back toward Earth for splashdown. This path uses less fuel and reduces certain risks compared with entering lunar orbit.
About a day after launch, the spacecraft will perform a translunar injection burn to send the crew toward the moon. The flight will bring them to roughly 5,000 miles above the lunar surface — much higher than Apollo missions, which typically orbited within about 100 miles or landed. Mission scientist Barbara Cohen said the far-side pass will look, from their distance, like “a basketball held at arm’s length.”
Testing, testing
After separating from the rocket, but before committing to the lunar leg, the crew began testing the Orion spacecraft in high-Earth orbit. Hours after reaching that orbit, they performed a proximity operations test, taking manual control to evaluate how the vehicle handles in space.
Pilot Victor Glover said the exercise confirms the vehicle flies as designed and will be useful for future missions that may require docking with a lunar lander. Although docking is likely to be automated, NASA wants to know how Orion responds if astronauts must command it manually. Near the end of the maneuver, Glover reported favorably: “Overall guys, this flies very nicely.”
Time for science
The astronauts themselves are subjects for biomedical research because they will travel farther into deep space than humans have before. Medical teams will collect data on physiological changes and increased radiation exposure; the mission carries tiny chips containing crew cells distributed throughout the capsule to study radiation effects more precisely.
Crew members will also act as field geologists, observing and photographing features on the lunar far side that no human has seen. Geologists on Earth trained them to identify unique surface features to aid scientific study and future landing planning. As Cohen noted, the high-altitude flyby offers a broad strip-like perspective of the moon similar to a long-distance aerial view.
Artemis II also carries CubeSats from Germany, South Korea, Saudi Arabia and Argentina. Those small satellites will study space radiation effects on hardware, monitor space weather, and evaluate how the lunar environment affects electrical systems intended for future lunar missions.
Heading home
On return, the Orion capsule will hit Earth’s atmosphere at nearly 25,000 miles per hour. Atmospheric friction will raise exterior temperatures to close to 3,000 degrees Fahrenheit, so the capsule relies on its heat shield for protection. After an uncrewed test flight in 2022 revealed unexpected heat-shield damage, NASA plans a steeper reentry angle for Artemis II than for Artemis I to reduce the time spent in peak heating.
Once through the worst of reentry, eight parachutes will deploy to slow the capsule before it splashes down in the Pacific Ocean off California. Airbags will help ensure the capsule lands right-side up. A recovery team at sea will retrieve the astronauts and conclude the mission.
What comes next
Lessons from Artemis II are critical to future Artemis missions. Last week, NASA administrator Jared Isaacman announced plans to increase launch frequency and pursue a permanent lunar surface base, efforts that hinge on validating systems and procedures on this flight.
“It is our strong hope,” said mission specialist Christina Koch, “that this mission is the start of an era where everyone, every person on Earth, can look at the moon and think of it as also a destination.”