After orbiting the Earth for a day after its launch, the National Aeronautics and Space Administration’s (Nasa) Artemis II mission, carrying four astronauts, has changed course and begun its journey to the Moon.

The mission’s Orion spacecraft fired its main engine for five minutes and 50 seconds beginning at 7.49 pm Eastern Daylight Time on Thursday, completing a translunar injection (TLI) burn—a propulsive manoeuvre that directs a spacecraft toward the Moon.

The manoeuvre successfully sent Orion and its crew out of the Earth’s orbit and onto a trajectory to complete its trip around the Moon, Nasa said in a release.

The critical engine burn came after mission teams gave a final “Go” for the manoeuvre, marking one of the most important milestones of Artemis II so far. Orion’s main engine, capable of producing up to 6,000 pounds of thrust, delivered the push needed to send the spacecraft beyond Earth’s gravitational hold.

At the time of the burn, Orion weighed about 58,000 pounds and used roughly 1,000 pounds of fuel during the firing. The power generated is sufficient to take a car from a standstill to 60 miles per hour in just 2.7 seconds.

With the burn now complete, the crew is officially on its path to the Moon, setting the stage for a historic flyby in the coming days.

As the spacecraft journeys deeper into space, the astronauts are adjusting to life on board the Orion spacecraft. The astronauts are keeping their physical health in check using a flywheel exercise device that is specifically designed for deep-space missions.

Unlike the large and complex gym equipment on the International Space Station, Orion’s exercise system is lightweight and efficient. Weighing just 30 pounds and roughly the size of a carry-on suitcase, the device allows astronauts to perform both aerobic and strength-based workouts, including rowing, squats, and deadlifts. It uses a cable-based system that can support a force of up to 400 pounds.

During these sessions, teams on Earth closely monitor the spacecraft’s air revitalisation system. This not only makes the cabin air comfortable for the astronauts but also helps the team on Earth understand the effect of the exercise on the movement of the spacecraft.

The four-member crew—Nasa astronauts Reid Wiseman, Victor Glover, Christina Koch, and Canadian Space Agency astronaut Jeremy Hansen—has also undertaken the first checks on the onboard system.

These include the AVATAR scientific payload, which has been successfully tested. In addition, engineers quickly fixed a brief communication problem that occurred shortly after the spacecraft reached orbit. The problem was related to the configuration of the ground system involving the Tracking and Data Relay Satellite system.

With the spacecraft on its trajectory to the Moon, the focus is now on the flyby. The team is developing a detailed ‘Lunar Targeting Plan’ to determine what the astronauts will see during their six-hour flyby.

The plan includes an examination of surface characteristics such as craters, ancient lava flows, and fractures to gain insight into how the Moon and the rest of the solar system evolved.

The most awaited occurrence of the flyby will be a solar eclipse lasting nearly an hour. As the Sun moves behind the Moon from Orion’s position, the crew will see a darkened lunar surface. This will enable astronauts to witness flashes of light from meteoroids striking the Moon, see dust rising off the edge of the Moon, and even see distant planets. During this period, they will also be able to see the outer layer of the Sun, referred to as the corona.