Orbital ATK completed its fourth cargo delivery mission (OA-4) to the International Space Station (ISS), including the initial demonstration flight and three operational missions under NASA's Commercial Resupply Services (CRS) contract. Orbital ATK's Cygnus spacecraft delivered 7,700 pounds of cargo to the ISS, the largest cargo shipment to date by a commercial company.

The company is now preparing for its next cargo mission in March from Cape Canaveral Air Force Station, Florida, using its enhanced Cygnus spacecraft to deliver vital supplies and experiments to the ISS. Two additional CRS missions scheduled later this year will launch aboard the company's upgraded Antares rocket from NASA's Wallops Flight Facility in eastern Virginia.

The Cygnus spacecraft that carried out the OA-4 mission unberthed from the ISS on February 19, completing a 72 day stay at the orbiting laboratory. Prior to its departure, the astronauts loaded the cargo module with approximately 3,000 pounds (over 1,400 kilograms) of items for disposal. Cygnus performed a safe, destructive reentry into the Earth's atmosphere over the Pacific Ocean east of New Zealand on February 20 at approximately 11:00 a.m. (EST), marking the successful conclusion of the mission.

"Orbital ATK made history with the OA-4 mission, delivering a record amount of cargo by a commercial system to the ISS," said Frank Culbertson, President of Orbital ATK's Space Systems Group. "From launch to our safe reentry, the entire Orbital ATK team performed flawlessly on every phase of this mission. We now turn our efforts toward final preparations for the next Cygnus cargo mission in March with a continued focus on supporting the needs of the crew members aboard the ISS."

The OA-4 mission began on December 6, 2015, when a United Launch Alliance (ULA) Atlas V rocket launched Cygnus into orbit from Cape Canaveral Air Force Station, Florida. Cygnus berthed with the ISS three days later, successfully delivering vital supplies and science experiments to the astronauts onboard.

Preparations are well underway for the company's next CRS mission, known as OA-6. The Cygnus pressurized cargo and service modules for OA-6 have been mated and are being processed at NASA's Kennedy Space Center for integration with the ULA Atlas V rocket. Cygnus is scheduled to launch aboard the Atlas V in March from Cape Canaveral Air Force Station, Florida. Orbital ATK and ULA are targeting a launch date of March 22 for the mission pending final approval from the Eastern Range.

Following OA-6, Orbital ATK plans to resume cargo resupply missions with its enhanced Cygnus spacecraft and upgraded Antares launch vehicle from the Mid-Atlantic Regional Spaceport (MARS) located at NASA's Wallops Flight Facility in eastern Virginia. At least two CRS missions, OA-5 and OA-7, are scheduled to launch from MARS in the second and fourth quarters of this year.

By the end of 2018, Orbital ATK is scheduled to have completed 10 CRS missions and delivered approximately 59,000 pounds (26,800 kilograms) of cargo to the ISS. Beginning in 2019, the company will begin carrying out a minimum of six initial cargo missions under the recently awarded CRS-2 contract, continuing to support the needs of crew members aboard the ISS with mission success and schedule certainty.