United Launch Alliance announced this week it has selected Blue Origin's BE-4 engine over Aerojet Rocketdyne's AR-1 to power its new Vulcan Centaur rocket -- the centerpiece of its proposal for the Air Force's competition to build a next-generation launch vehicle. "Following completion of a competitive procurement, ULA has selected Blue Origin's BE-4 engine for Vulcan Centaur's booster stage," the company said in Sept. 27 press release. "The liquefied natural gas (LNG) fueled booster will be powered by a pair...
