'We are proud to serve our country, both on Earth and in space': NASA astronauts beam home July 4 message from ISS (video)

Three NASA astronauts living aboard the International Space Station (ISS) marked Independence Day with a few heartfelt words for their compatriots here on Earth.

It was written by the American members of the station's current Expedition 73 mission, Nichole Ayers, Jonny Kim and Anne McClain.

All three are members of the U.S military — Ayers is a lieutenant colonel in the Air Force, McClain is an Army colonel and Kim is a lieutenant commander in the Navy, as well as a former SEAL — so Independence Day has a special meaning for them.

"This is a special holiday for me. It just reminds us of the freedom that we get to enjoy and that we have enjoyed for so many years," Ayers said in a 160-second video, which was recorded on June 16 but posted by NASA on Thursday (July 3).

"Protecting that freedom is important to all of us here as military officers, but also NASA astronauts," she added. "And we are proud to serve our country, both on Earth and in space."

"For me, the Fourth of July represents the responsibilities that we each have — to whom much is given, much is expected," McClain said. "Our forefathers gave us the rights of life, liberty and the pursuit of happiness, and every generation must protect that for future generations."

Kim said the Fourth of July is a "deep day of reflection" for him, an occasion to remember American ideals and honor the sacrifices of those who have helped uphold them.

"And to those following our mission, the spirit of exploration, just like the spirit of freedom and democracy, is what has made our country so great," he added.

The trio spoke in front of a large American flag, which they had affixed to an ISS module wall. They also provided more patriotic flair toward the end of the video: All three did a celebratory backflip, revealing socks with a stars-and-stripes theme.

Ayers, McClain and Kim aren't the only Americans currently living on the orbiting lab. It also houses record-setting former NASA astronaut Peggy Whitson, who's now the director of human spaceflight for the Houston-based company Axiom Space.

Whitson is commanding Axiom's four-person Ax-4 mission, which arrived at the ISS on June 26 for a roughly two-week stay. Her three crewmates are pilot Shubhanshu Shukla of India; mission specialist Sławosz Uznański-Wiśniewski, a European Space Agency astronaut from Poland; and mission specialist Tibor Kapu, who hails from Hungary.

There are four other people on station at the moment as well, all of them members of Expedition 73: cosmonauts Kirill Peskov, Sergey Ryzhikov and Alexey Zubritsky, as well as Takuya Onishi of JAXA (the Japan Aerospace Exploration Agency).