A Boeing Delta 2 rocket has successfully sped NASA’s Mars rover Spirit out of Earth orbit to begin a seven-month journey to the Red Planet. Finding a hole in cloudy skies over Florida’s Space Coast, the three-stage booster lifted off at 1:58:47 p.m. EDT (1758.47 GMT) Tuesday. Afternoon thunderstorms, so common over the Florida peninsula during the summer months, had forced NASA to call off launch attempts on Sunday and Monday. But conditions remained clear enough Tuesday to allow the shot. During the next 39 minutes the rocket stepped through its launch sequence, much of it broadcast live on NASA TV thanks to presence of a rocketcam bolted to the side of the vehicle.