How many people have spent Christmas Day in space before the International Space Station?

Before the International Space Station (ISS), a total of six people spent Christmas Day in space. This includes astronauts from the Apollo, Skylab, and space shuttle missions. The first Christmas in space was celebrated by the Apollo 8 crew in 1968, who famously read from the Book of Genesis while orbiting the Moon. Subsequent missions also marked the holiday in space, contributing to the tradition that continues aboard the ISS today.