Humans evolved to walk on two legs, on a planet with plenty of gravity and relatively consistent air pressure. It’s no wonder, then, that being blasted into space is hard on our squishy little bodies. Strange things start to happen. 

Just what those things are, and how they change over time, is the subject of ongoing research. Astronaut Scott Kelly is in space now and will stay there for more than a year while researchers on the ground track the effects of the zero-G lifestyle on his body. 

There are some things we already know about the physical consequences of space travel. In this video from Great Big Story, astronaut Leland Melvin explains some of the basic changes you can expect on your next trip into space: a longer spine, a shrunken heart, and a sudden need for glasses. 

Melvin is no stranger to the spotlight; the engineer and former football star made headlines in early 2015 when he invited his dogs to join him in his official NASA portrait. The results, as you can see, were wonderful.

NASA, Wikimedia Commons // Public Domain

Header image courtesy of Great Big Story