Image Credit & Copyright: Orbital Sciences.
Just a quick update on the Orbital Sciences situation:
On December 9, 2014 it was announced by Orbital Sciences that they and the United Launch Alliance (ULA) have teamed up to launch a Cygnus cargo vehicle to the ISS on the nose of an Atlas V rocket from the Cape Canaveral Air Force Station (CCAFS) in the fourth quarter of 2015 with another in early 2016 if needed. The Atlas V rocket will provide a greater lift capacity than the Antares which will allow for a 35% cargo increase per flight.
Orbital is fast tracking the development of their new rocket engines and plan to be flying with Antares again in the first, second and fourth quarters of 2016. This new engine will reportedly provide a 20% increase in payload capacity to the Antares launch vehicle. The new rocket engines are slated to arrive at Wallops for integration and testing in mid-2015.
All in all, if this goes as planned all contracts with NASA should be fulfilled with only minor delay.
Orbital Sciences press release regarding this topic: https://www.orbital.com/NewsInfo/release.asp?prid=1928