ars technica: This decision was widely expected due to several problems with the rocket, Orion spacecraft, and ground launch systems. by Eric Berger
'The delay was confirmed in a letter from a NASA official released Thursday by the US Government Accountability Office.
'"We agree with the GAO that maintaining a November 2018 launch readiness date is not in the best interest of the program, and we are in the process of establishing a new target in 2019," wrote William Gerstenmaier, chief of NASA's human spaceflight program. "Caution should be used in referencing the report on the specific technical issues, but the overall conclusions are valid."'