SpaceX is set to launch its second operational commercial crew mission to the International Space Station for NASA, with a liftoff time of 5:49 AM EDT (2:49 AM PDT) on Friday morning. The flight will carry four astronauts, including two from NASA, one from JAXA (the Japan Aerospace Exploration Agency) and one from the ESA (European Space Agency), to the station, where they will begin a regular tour of duty conducting science experiments, and maintaining and upgrading the orbital platform. This is the second commercial crew mission for SpaceX, which officially qualified its Dragon spacecraft and Falcon 9 rocket for human flight last year.