Astronauts aboard the International Space Station spoke with the Artemis II crew on April 8 following their lunar flyby, marking a rare ship-to-ship exchange between deep space and low Earth orbit. The Artemis II crew is returning to Earth after circling the Moon, while Expedition 74 astronauts continued biomedical research and mission training aboard the station. The interaction highlighted how ongoing ISS science supports future lunar missions under NASA’s Artemis program.

For a few minutes on Tuesday, two crews separated by hundreds of thousands of miles shared the same conversation.

Astronauts aboard the International Space Station (ISS) connected with their counterparts on NASA’s Artemis II mission, offering a rare moment of overlap between low Earth orbit operations and deep space travel. The call came just a day after Artemis II astronauts completed a historic lunar flyby and began their journey home.

On one side were Expedition 74 crew members Chris Williams, Jack Hathaway and Jessica Meir of NASA, along with Sophie Adenot of the European Space Agency (ESA). On the other were Artemis II astronauts Reid Wiseman, Victor Glover and Christina Koch, joined by Jeremy Hansen of the Canadian Space Agency (CSA).

The Artemis II crew is traveling aboard Orion, returning to Earth after looping around the Moon in NASA’s first crewed lunar mission in decades.

ISS and Artemis II crew exchange experiences after lunar flyby

The conversation turned quickly to comparison.

Station astronauts asked about differences between spacecraft, while Artemis II crew members described the experience of seeing the Moon up close. Christina Koch, drawing on her own time aboard the ISS, linked the two missions directly.

“Every single thing that we learned on ISS is up here,” Koch said, referring to how station-based training translates to deep space operations.

The exchange underscored a key role of the ISS within the Artemis program. The orbiting laboratory functions as a proving ground where astronauts refine procedures, test systems and adapt to long-duration spaceflight before venturing farther from Earth.

For NASA and its partners, that continuity is central. The Artemis II mission builds on lessons accumulated over years of station operations.

The Artemis II crew – (clockwise from left) Mission Specialist Christina Koch, Mission Specialist Jeremy Hansen, Commander Reid Wiseman, and Pilot Victor Glover – pause for a group photo with their zero gravity indicator “Rise,” inside the Orion spacecraft on their way home. Following a swing around the far side of the Moon on April 6, 2026, the crew exited the lunar sphere of influence (the point at which the Moon’s gravity has a stronger pull on Orion than the Earth’s) on April 7, and are headed back to Earth for a splashdown in the Pacific Ocean on April 10.

Space station biomedical research supports Artemis and future missions

While the call captured public attention, the station’s daily schedule remained anchored in research.

Crew members conducted a series of biomedical scans using the Ultrasound 3 device, focusing on how spaceflight affects the human body. Doctors on the ground monitored the scans in real time, looking for signs of blood clots that can form in leg veins and travel to the lungs.

Such risks have become a growing area of study as missions extend beyond short orbital stays. Data collected aboard the ISS feeds directly into planning for longer journeys, including missions to the Moon and eventually Mars.

Jessica Meir also contributed to the RelaxPro investigation, an ESA-sponsored study examining stress and immune responses in space. She collected saliva and hair samples that researchers will analyze on Earth for hormonal and immune markers.

The study explores whether mindfulness and meditation techniques can improve sleep quality and reduce stress during long-duration missions.

Cargo mission training and robotic systems testing on ISS

Operational training continued alongside scientific work.

Williams and Hathaway simulated the capture of the Cygnus XL cargo spacecraft using the Canadarm2 robotic system. Mission planners are targeting April 10 for the launch of the resupply mission aboard a **SpaceX Falcon 9 rocket, which will deliver supplies and experiments to the station.

Elsewhere, Sophie Adenot worked inside the Japanese Kibo laboratory module, setting up a compact experimental robotic arm known as TUSK. The system is being tested for precise movements at sub-millimeter levels in microgravity, a capability that could support delicate operations in future missions.

Adenot later joined fellow astronauts for emergency response simulations, rehearsing procedures designed to prepare crews for unexpected situations in orbit.

Roscosmos crew studies teamwork and fitness in orbit

Russian crew members also focused on research tied to long-duration missions.

Station commander Sergey Kud-Sverchkov and flight engineer Sergei Mikaev, both representing Roscosmos, participated in experiments examining team dynamics and physical conditioning in space. One study involved progressively complex computer tasks requiring cooperation, allowing researchers to observe how crews adapt to working together in confined environments.

The findings may influence crew training for future missions beyond Earth orbit.

Kud-Sverchkov later completed a monitored exercise session using an onboard cycle, while Mikaev assisted with health data collection.

Meanwhile, Andrey Fedyaev continued training with the European robotic arm inside the Nauka module, practicing both primary and backup control modes to ensure operational readiness.

The day’s activities reflected a layered mission environment.

On one level, astronauts pushed the boundaries of human spaceflight, exchanging insights between deep space and orbit. On another, they maintained a steady cadence of experiments and training that will shape future exploration.

The Artemis II crew moves farther from the Moon with each passing hour. The ISS crew remains in orbit, continuing work that helps make those journeys possible.