NASA is nearing one of the most consequential tests in its modern history as it prepares to launch its first crewed Moon mission in more than half a century, a flight that could shape the future of U.S. human space exploration.

The mission, known as Artemis II, is expected to lift off as early as February and will send four astronauts on a journey around the Moon, marking the first time humans have traveled beyond near-Earth orbit since the final Apollo mission in 1972. The crew includes NASA astronauts Reid Wiseman, Victor Glover and Christina Koch, as well as Canadian Space Agency astronaut Jeremy Hansen.

Artemis II is part of NASA’s Artemis program, an initiative unveiled in 2017 aimed at returning astronauts to the Moon and laying the groundwork for a long-term human presence there. While the mission will not include a lunar landing, it is designed to validate the spacecraft, systems and procedures required for future landings later this decade.

The astronauts will fly aboard the Orion capsule, which will travel on a wide looping trajectory around the Moon before returning to Earth. The flight path is intended to safely guide the spacecraft home even if its propulsion system fails, reflecting lessons learned since the Apollo era and Orion’s larger size and mass.

NASA officials have said the mission carries significant risk, as the agency has not conducted a crewed deep-space flight in more than 50 years. Although Orion completed an uncrewed test flight during the Artemis I mission in 2022, Artemis II will be the first time the spacecraft’s life-support, navigation and communication systems are tested with astronauts aboard.

The mission will expose the crew to higher levels of radiation than astronauts experience aboard the International Space Station, which orbits within Earth’s magnetic field. Researchers plan to collect detailed health data during the flight, tracking sleep patterns, cognitive function, immune response and cardiovascular performance to better understand how the human body responds to prolonged deep-space conditions.

Engineers are also closely watching the performance of Orion’s heat shield, which protects the capsule during its high-speed return through Earth’s atmosphere. During the Artemis I test flight, the heat shield showed unexpected wear, prompting months of analysis and design refinements. NASA officials have said they are confident the modifications will allow the system to perform safely during the crewed mission.

While orbiting the Moon, the astronauts will conduct visual observations and collect data on the lunar surface, including areas on the Moon’s far side that are not visible from Earth. The information gathered is expected to support planning for future missions, including a planned landing near the Moon’s south pole, a region of scientific interest due to the presence of water ice.

NASA has described Artemis II as a critical stepping stone toward its longer-term goals, which include establishing a sustained human presence on the Moon and eventually sending astronauts to Mars.

If successful, the mission would represent the most significant advance in U.S. human spaceflight since the Apollo program and move NASA closer to its next era of deep-space exploration.