The crew of NASA's Expedition 53 got a special call in the middle of their workday on Thursday - from Pope Francis.
In a freewheeling conversation, the Pope discussed several themes with the International Space Station's astronauts and cosmonauts, ranging from their reasons for becoming who they are to humankind's place in the universe.
Here we bring you the best bits from their chat.
The society is individualistic, but we need collaboration, says Pope
The astronauts said that the greatest mission of science was to enrich knowledge and that it was a medium to unlock unsolved mysteries. They also shared how working in a space station has altered their worldview.
Pope Francis, in his turn, called their work the ultimate human experiment, and hailed the space station as the leading example of international teamwork and cohesiveness.
What is NASA's Expedition 53?
Expedition 53 started in September 2017 and will end in December 2017. It has six crew members - five flight engineers and one commander.
As part of the programme, the researchers are studying cosmic ray particles, investigating ways to improve muscle atrophy and testing a new drug that can accelerate bone repair, among other things. The expedition also includes three tentative spacewalks.