Everything you need to know about NASA’s Artemis II mission, bringing humans back to the moon

It’s been more than half a century since astronauts last stepped onto the moon. Now, NASA’s Artemis II will return four humans to its vicinity in a 10-day lunar loop that lifts off from NASA’s Kennedy Space Center as early as February 8. 

An Orion spacecraft will carry NASA’s Reid Wiseman, Victor Glover, and Christina Koch, as well as Canadian Space Agency astronaut Jeremy Hansen, some 230,000 miles to the far side of the moon—farther from Earth than anyone has traveled. Using a free-return trajectory enabled by lunar gravity, they will slingshot back to Earth for a splashdown off the coast of San Diego.

NASA’s Artemis program, along with private and international partners, aims to return people to the moon for scientific exploration, establish a lunar economy, and ultimately pave the way for crewed missions to Mars. An initial uncrewed lunar flyby, Artemis I, provided a proof of concept in 2002. This mission adopts a more human-centric approach, evaluating Orion’s life support systems in situ and gathering additional data on how spaceflight affects the human body. It may also offer views of the moon never before seen.

“I was around for Artemis I, and this one feels a lot different, putting the crew on the rocket and taking the crew around the moon,” said John Honeycutt, Artemis II mission management team chair, during a NASA press conference last month in advance of the rocket rollout to the launch pad. “This will be our first step toward sustained lunar presence on the moon.”

Life in deep space

Testing will begin almost immediately after NASA’s Space Launch System (SLS) rocket launches Orion into orbit with 8.8 million pounds of thrust, 15% more than that of Apollo’s Saturn V. Once in orbit, Orion will deploy solar arrays. Meanwhile, astronauts will conduct system checkouts and docking maneuvers in anticipation of future dockings, which could include lunar landers or the proposed lunar-orbiting Gateway Space Station. During the six-day mission, the astronauts will evaluate radiation shielding and operational, communications, and emergency systems

“We want to put Orion through its paces,” said Jeff Radigan, mission flight director, flight operations directorate.

The mission’s science goals include space weather measurements using four deployed international CubeSats (more easily deployable “building brick” satellites), lunar observation, and biometric responses. Astronauts will monitor their health and performance using immune system biomarkers and wearable devices that track sleep, stress, movement, and radiation exposure. Their findings may help future missions better optimize astronaut time.

The star science payload, however, is AVATAR (A Virtual Astronaut Tissue Analog Response), which uses tissue chips mimicking astronaut organs and bone marrow to gauge how spaceflight affects blood cells and other systems. The mission will mark AVATAR’s first use outside the Van Allen belts, bands of high-energy radiation particles surrounding Earth. The space agency hopes to measure human responses to deep-space stress by comparing its data with International Space Station findings and Artemis crew samples collected before and after flight.

“For NASA, AVATAR could lead to personalized medical kits for each astronaut or, for folks back on Earth, individualized treatments for diseases such as cancer,” said Jacob Bleacher, chief exploration scientist, exploration systems development mission directorate.

The mission also plans to attract public interest by dedicating a day to observing the moon’s hidden dark side. From Orion’s farthest vantage point—4,700 miles beyond Earth’s satellite, the moon will seem the size of a basketball held at arm’s length, with our planet appearing in the distance. Pending the crew’s launch time and flight path, Bleacher added, “it’s possible they’ll see parts of the moon that have never been viewed by human eyes.”

The spacecraft’s return home will occur naturally, using Earth’s and the Moon’s gravity to enter Earth orbit without propulsion or complex course corrections. Reentry from the moon into Earth’s atmosphere will be faster than from low-Earth orbit, requiring more parachutes. However, following a finding that parts of the Artemis I heat shield degraded more than expected upon reentry, Artemis II will engage a shorter entry range. While this approach is safer, it reduces the number of potential launch days.

Yet even with this adjustment, retired astronaut Charles Carmarda and former NASA engineer Daniel Rasky have raised grave concerns about the heat shield’s efficacy. “If I had to rate it an A, B, C, D, or E, I’d rate it an F,” Rasky told ABC News last week.

Postflight, the crew will attempt an obstacle course and a simulated spacewalk with tasks while wearing pressurized spacesuits. The exercises, which will gauge how quickly astronauts can function after a gravity transition, should help preparations for future lunar and Mars landings.

Expecting the unexpected

The Artemis infrastructure is a work in progress. “Over time, launching missions like this, we’re going to learn a lot and the vehicle architecture will change,” noted NASA Administrator Jared Isaacman during a follow-up media event with the astronauts. “And as it changes, we should be able to take repeatable, affordable missions to and from the moon. Reusability is what’s going to enable missions like Artemis 100.”

As the crew engages in final preparations, including hard talks with their families about the inherent risks of spaceflight, they’ve learned to balance focus with the unexpected.

“This is the first time we’ve put humans on this rocket,” said Hansen, who will become the first non-American astronaut to travel beyond low Earth orbit on a NASA mission. “We’ve done a lot of testing of these systems, but when we get to space, we’ll probably see signatures that look a little bit different from testing.”

The sheer distance creates its own set of demands, even for a veteran like Koch, who set the record for the longest single spaceflight by a woman at 328 days.

“I really have to make sure my husband knows that it’s not like the International Space Station, where we can just make a phone call,” she said with a grin. “So, he’s not going to be able to call me and ask where something is in the house. He’s going to have to find it.”