13 feb 2013 año - Phase 1 (amended)
Descripción:
 "allowed the Air Force to procure up to 35 launch vehicle cores (a core is the main rocket body; the Delta IV Heavy consists of three cores) over a five year ordering period, 2013-2017 and provide the associated launch capability from 2013-2019.  The Air Force awarded a sole source contract with a requirements type component to United Launch Alliance (ULA) that provided a long-term commitment in exchange for much lower launch service prices and substantial manifest flexibility.  This contract with ULA was deemed to be “Phase 1” of the EELV program."
https://www.afspc.af.mil/About-Us/Fact-Sheets/Article/249026/evolved-expendable-launch-vehicle/ 
Añadido al timeline:
fecha:
13 feb 2013 año
Ahora mismo
 ~ 12 years ago