The weightless environment provides a unique perspective on physical systems and processes, and is helping researchers to better understand disease and to develop new materials.

BBC: Virgin spaceship aims to be science lab

This time, Dragon capsule's sensors, navigation computers and automated propulsion system, never before fully tested in the harsh environment of space, are supposed to maneuver the capsule in a weightless ballet to within 1.5 miles of the space station and then maintain control as Dragon drifts closer.

WSJ: SpaceX's Pioneering Flight Plans