The four space station astronauts that comprise the SpaceX Crew-4 mission are due to return to Earth soon after a scientific journey that included observing how immune cells age in space, studying effective space nutrition, growing crops without soil to sustain crews, and exploring ways to improve fire safety on spacecraft, among a multitude of other space science experiments. From left, are NASA astronauts Jessica Watkins, Bob Hines, and Kjell Lindgren, with ESA (European Space Agency) astronaut Samantha Cristoforetti. The quartet talked with journalists on Earth about their months-long space research mission ahead of their return to Earth. #nasa #esa #astronaut #science #research #international #space #station #crew4