ULA reviewing early shutdown by Atlas V engine

The main engine of United Launch Alliance's Atlas V rocket shut down six seconds earlier than planned Tuesday night, but the glitch did not prevent the rocket from delivering an International Space Station resupply mission to its intended orbit, the company confirmed Thursday. ULA said the premature shutdown resulted from the kerosene-fueled RD-180 engine burning with a higher than normal ratio of liquid oxygen, for reasons now under review. To make up for the booster's early cutoff, the rocket's Centaur upper stage RL10C engine, provided by Aerojet Rocketdyne, performed an extended burn before dropping off Orbital ATK's unmanned Cygnus cargo ship in an orbit about 150 miles above the planet. More

(Source: Florida Today - Mar 25)