A US astronaut, Frank Rubio, returns to Earth after 371 days.

A US astronaut, Frank Rubio, returns to Earth after 371 days.

After over a year in space, Frank Rubio must adjust to gravity. “Your lower back and the soles of your feet hurt a little bit the first few days,” he said at a Friday press briefing at NASA Johnson Space Center in Houston, Texas. “ “I believe that because your lower back now bears half of your weight, there is…