DIscovery blasted off on time at 7:43 pm EST and has reached orbit. Mission STS-119 will deliver the final set of giant solar arrays to the ISS and switch out one of the station's crew. Japanese astronaut Koichi Wakata will remain on board for about 6 months, while astronaut Sandy Magnus will come home with the STS-119 crew. Kawata will be the first Japanese member of the space station crew, currently Expedition 18.
The new power panels will allow the station to finally reach its intended crew of 6.