You may have heard people say that aboard the International Space Station (ISS) there's "zero gravity," but in fact, gravity is still very much present. The station orbits Earth at an altitude of ...

In a quiet corner of the International Space Station, far from the bustle of experiments and Earth communications, three small robotic cubes drift through the air like hummingbirds in slow motion.

It's well known that spaceflight causes muscle atrophy and other biological changes in reduced gravity, and especially in near-zero gravity (microgravity) environments. However, the gravity threshold ...