Orbital Sciences has announced new details in its plans to resume cargo flights to the International Space Station (ISS) and to accelerate the introduction of an upgraded Antares launch vehicle.

In formulating its go-forward plans, the company's primary objective is to fulfill its commitment to NASA for ISS cargo deliveries with high levels of safety and reliability and minimum disruption to schedules.

As previously announced, these plans are expected to allow Orbital to accomplish all remaining cargo deliveries under its current Commercial Resupply Services (CRS) contract with NASA by the end of 2016 and with no cost increase to the space agency.

The company's go-forward plans for the CRS program and Antares launch vehicle include these major elements:

+ Atlas V Launch: Orbital has contracted with United Launch Alliance for an Atlas V launch of a Cygnus cargo spacecraft from Cape Canaveral, Florida, in the fourth quarter of 2015, with an option for a second Atlas V launch in 2016 if needed. The Atlas rocket's greater lift capacity will allow Cygnus to carry nearly 35% more cargo to the ISS than previously planned for CRS missions in 2015.

+ Antares Propulsion Upgrade: The company has confirmed its ability to accelerate the introduction of a new main propulsion system for the Antares rocket and has scheduled three additional CRS launches in the first, second and fourth quarters of 2016 using the upgraded vehicle. The greater payload performance of the upgraded Antares will permit Cygnus spacecraft on each of these missions to deliver over 20% more cargo than in prior plans. With necessary supplier contracts now in place, the first new propulsion systems are expected to arrive at the Antares final assembly facility at Wallops Island, Virginia in mid-2015 to begin vehicle integration and testing.

+ Wallops Launch Site Repairs: The Mid-Atlantic Regional Spaceport (MARS) has assessed the clean-up, repair and reconstruction work necessary to return the Wallops launch complex to operational status. Current plans call for repairs to be substantially completed by the fall of 2015, with recertification taking place before year end.

The flexibility of Orbital's Cygnus cargo spacecraft to accommodate heavier cargo loads, together with the greater lift capacity of the Atlas V and upgraded Antares vehicles, will allow the company to complete all currently contracted ISS deliveries in four missions instead of the five previously planned flights over the next two years.

In addition, the company's revised approach is not expected to create any material adverse financial impacts in 2015 or future years as Orbital carries out the CRS cargo delivery and Antares propulsion upgrade programs.