Clouds of smoke and steam roll as space shuttle Discovery roars into the night sky on the STS-119 mission.

Clouds of smoke and steam roll across Launch Pad 39A at NASA's Kennedy Space Center in Florida as space shuttle Discovery roars into the night sky on the STS-119 mission. The launch was on time at 7:43 p.m. EDT. The STS-119 mission is the 28th to the International Space Station and the 125th space shuttle flight. Discovery will deliver the final pair of power-generating solar array wings and the S6 truss segment. Installation of S6 will signal the station's readiness to house a six-member crew for conducting increased science. Photo credit: NASA/Sandra Joseph, Kevin O'Connell