Sunita Williams and Butch Wilmore begin their 45-day rehabilitation program to readjust to Earth's gravity. During this period, medical experts will closely monitor them for potential health issues.

YOU MIGHT BE absolutely crushing it in the gym, getting the most out of every rep by pushing your muscles to their max. If you're not properly fueling yourself outside of your workouts ...

Researchers are working on artificial muscles that can keep up with the real thing. They have now developed a method of producing the soft and elastic, yet powerful structures using 3D printing.