Aerojet Rocketdyne [AJRD] and United Launch Alliance (ULA) brass will meet in February to gauge Aerojet Rocketdyne’s progress on its AR1 engine that the company is marketing as a drop in replacement for the politically-beleaguered Russian RD-180 engine.Aerojet Rocketdyne President and CEO Eileen Drake said Tuesday the company passed a preliminary design review (PDR) for the AR1 in December and anticipates a critical design review (CDR) taking place by the end of 2016. In addition to marketing AR1 as a…