"It takes courage, grit, and freedom to chase the unknown. It’s the purest kind of American spirit," said Brown in a voice recording played aboard Integrity

The Artemis II crew woke up to the sound of Zac Brown‘s song “Free” during their time in space. The country singer and his partner, jewelry designer Kendra Scott, announced the news on Friday, April 10.

In a clip shared to social media, Brown’s hit song can be heard playing on the Orion spacecraft, which the crew named Integrity, during their eighth day in space. “Good morning Reid, Victor, Christina and Jeremy,” he told them. “Zac from Zac Brown Band here, checking in from the U.S.A. We hope that piece of our song, ‘Free,’ helps start your day with the right kind of lift. We just want to say how proud we are of you. It takes courage, grit, and freedom to chase the unknown. It’s the purest kind of American spirit.”

He singer continued, “Millions back home are looking up and feeling more inspired because of you. Keep flying strong. Keep flying safe. We can’t wait to welcome you home. Come see us on the road.”

The four astronauts aboard Artemis II — commander Reid Wiseman, pilot Victor Glover and mission specialists Christina Koch of NASA and Jeremy Hansen of the Canadian Space Agency — are set to return to Earth on Friday, April 10, and splash down in the Pacific Ocean.

The Artemis II lunar mission launched on April 1 at 6:35 p.m. Eastern Time, and marked humanity’s first trip around the moon in over 50 years. The astronauts traveled farther from our planet than any human during their loop around the moon this week, breaking the previous record set by Apollo 13 in 1970. According to NASA, their flight is a critical step toward establishing systems to help future astronauts in deep space exploration and returning humans back to the moon for the first time since 1972.