After astronaut Scott Kelly returned from his history making year in space, NASA hosted a Reddit forum to answer questions posed by space enthusiasts. Below are some of my questions, and NASA’s answers.

Mike: When will Scott Kelly lose the extra inches of height that he gained from being in space? Or is that a permanent physical change?


NASA: Recovery is super quick – essentially just by adding gravity back into the mix. The results aren’t permanent. SM


NASA: As soon as Scott returned to gravity and stood up, gravity began to compress his spine again. Most likely, he is already back to his pre-launch height. sm


Mike: How comparable is the microgravity Kelly experienced in Earth’s orbit to what travelers to Mars would experience on their journey?


NASA: The microgravity is the same as a transit to Mars. But once the crew lands on Mars they will be in 3/5 of Earth gravity. -JR


The NASA scientists and doctors involved in this particular forum were:

Julie Robinson, Ph.D., NASA’s Chief Scientist for the International Space Station

John Charles, Ph.D., Associate Manager for International Science for NASA’s Human Research Program

Scott M. Smith, Ph.D., Nutritional Biochemistry Laboratory Manager for NASA’s Human Research Program

Dr. Shannan Moynihan, NASA Flight Surgeon

Bruce Nieschwitz, Astronaut Strength and Reconditioning Coach

If you’re interested in reading the rest of the questions and answers from this forum, follow the link here.