A recent article on Space on MSNBC.com shows astronaut Leroy Chiao performing an eye examination onboard the International Space Station. The exam was performed on Salizhan Sharipov, a cosmonaut who took advantage of NASA’s ultrasound-based “all purpose diagnostic machine”. This ultrasound machine is unique, in that it is directly linked from the Space Station to doctors on Earth. Why use ultrasound machines in space? Like most of the other space-bound experiments, it has a practical application.