The first Delta IV Heavy liftoff from Vandenberg AFB, Calif., illustrated the dramatic purge of hydrogen that results in flames swirling around the three Pratt & Whiney Rocketdyne RS-68 Common Core Booster engines that comprise the first stage. The Jan. 20 launch from Space Launch Complex-6 (SLC-6) boosted the classified NROL-49 mission into a highly inclined orbit for the National Reconnaissance Office (NRO). Because it was classified, details on the payload, its orbit and the results of the liftoff were not announced. But United Launch Alliance (UAV) reports, “The pad is in great shape and the rocket performed as the...