The Nuclear Spectroscopic Telescope Array (NuSTAR) spacecraft launched spaceward at the tip of an Orbital Sciences Pegasus XL rocket, which itself was carried into launch position by a high-altitude L-1011 "Stargazer" jet aircraft. At 12 p.m. EDT (1600 GMT), the plane dropped the rocket in midair, where the booster fired its engines for its climb into the sky.