The head of NASA appealed to Congress on Friday to put more money into restoring America's ability to send astronauts into space instead of relying on Russian rockets.
The space shuttle Endeavour is retired and on display at the California Science Center, but it's still contributing to the space program.
Gravity is a constant for all organisms on Earth. It acts on every aspect of our physiology, behavior and development – no matter what you are, you evolved in an environment where gravity roots us firmly to the ground.
ESA astronaut Paolo Nespoli will be heading for space a third time, as part of Expeditions 52 and 53 to the International Space Station. He will be launched on a Soyuz vehicle in May 2017 on a five-month mission.