Now five days into its historic journey, Artemis II is closing in on the Moon and preparing for Monday’s long-awaited lunar flyby. That will be the first time humans have traveled to the far side of the Moon since Apollo 17 in 1972.

The crew began Flight Day 5 Sunday morning with the mission’s first major test objective: a full evaluation of the Orion Crew Survival System suit. The crew suited up, pressurized their suits, and strapped in to assess performance and mobility in microgravity, a critical checkout ahead of re-entry later this week.

Orion has now entered the lunar sphere of influence, or the point roughly 65,000 miles from the Moon where lunar gravity overtakes Earth’s pull on the spacecraft. A trajectory correction burn is also planned for the afternoon to fine-tune the free-return path ahead of Monday’s flyby. Mission managers and NASA science experts will brief reporters at 5:30 PM EDT on NASA’s YouTube channel.

Monday’s Flyby: Six Hours at the Moon

The main event for the mission comes tomorrow, Monday, April 6th. Artemis II will loop around the moon and start its return to Earth.

A six-hour lunar observation window opens at 2:45 PM EDT, when Orion’s main cabin windows will be angled toward the Moon and the crew will be close enough for detailed scientific observations. Closest approach — approximately 4,066 miles from the lunar surface — is expected around 7:02 PM EDT. From that distance, the Moon will appear roughly the size of a basketball held at arm’s length.

Earlier in the day, at 1:56 PM EDT, the crew is expected to break the all-time human spaceflight distance record set by the crew of Apollo 13 in 1970. Orion will reach a maximum of 252,757 miles from Earth — about 4,100 miles beyond the mark Apollo 13 set during its emergency free-return trajectory. The crew is expected to mark the milestone with remarks around 2:10 PM.

The science targets for the flyby have been finalized and uplinked to the crew Sunday afternoon. NASA’s lunar science team has assigned each astronaut specific surface features to observe and photograph, with a focus on regions difficult or impossible to study from Earth-based observatories.

That list includes portions of the Orientale basin, a massive, multi-ring impact crater straddling the Moon’s western limb that has never been seen directly by human eyes. The crew caught their first partial glimpses of it during Flight Day 4 and described the view as striking. “That is the dark side. That is something we have never seen before,” Koch told NBC News from orbit.

Forty Minutes of Silence

As Orion swings behind the Moon at approximately 5:47 PM EDT Monday, Mission Control in Houston will lose contact with the crew for roughly 40 minutes. The Moon itself blocks all radio signals between the Deep Space Network and the spacecraft during this period — the same type of planned blackout experienced during Artemis I and the Apollo missions. Flight Director Judd Frieling noted the crew will not be in any danger during the gap. “Physics takes over,” he said, “and physics will absolutely get us back.”

During the blackout, the crew will also witness a solar eclipse unlike any seen from Earth — the Moon blocking the Sun from Orion’s vantage point, exposing the solar corona for nearly an hour as the spacecraft arcs around the far side.

When Orion re-emerges from behind the Moon, the Deep Space Network is expected to quickly reacquire the signal and restore contact with Mission Control. The flyby observation window closes at 9:40 PM EDT.

Following Monday’s milestone, the crew will begin a four-day return coast to Earth, with splashdown in the Pacific Ocean off the coast of San Diego targeted for Friday, April 10.