Orbital ATK is in final preparations for the company's next CygnusTM spacecraft cargo mission to the International Space Station (ISS). This mission marks the first launch of a Cygnus spacecraft aboard a United Launch Alliance (ULA) Atlas V rocket and will be Orbital ATK's fourth operational mission (OA-4) to the ISS for NASA under the Commercial Resupply Services (CRS) contract. The mission also marks the debut of the enhanced Cygnus, which will carry approximately 7,700 pounds (3,500 kilograms) of cargo to astronauts aboard the ISS.

Pending completion of final vehicle testing and acceptable local weather conditions, the launch is scheduled for Thursday, December 3, at 5:55 p.m. (EST) from Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida.

Cygnus will be launched into a targeted orbit of 143 x 144 miles above the Earth, inclined at 51.64 degrees to the equator. Following in-orbit activation and testing after launch, the spacecraft will rendezvous and berth with the ISS December 6 at approximately 5:30 a.m. EST.

Orbital ATK has named the OA-4 Cygnus the "S.S. Deke Slayton II," upholding the tradition of naming each Cygnus in honor of astronauts and individuals who contributed to the United States' commercial space program.

"With the naming of this spacecraft, we continue our commitment to honor the late Donald 'Deke' K. Slayton, one of the original Mercury Seven astronauts and a champion of America's commercial space program and leadership in space," said Frank Culbertson, President of Orbital ATK's Space Systems Group.

"We are pleased that the enhanced Cygnus that bears his name will be able to provide up to 53 percent more in cargo weight to the International Space Station than our previously flown standard version."

Cygnus, like most Orbital ATK spacecraft, is compatible with multiple launch vehicles, enabling the use of ULA's Atlas V launch vehicle on this mission.

The enhanced Cygnus has several new features, including lightweight UltraFlexTM solar arrays, a mass optimized Service Module structure and a lighter weight propulsion system. In addition to food, clothing, crew supplies, spare parts and equipment, the Cygnus spacecraft is carrying science experiments to expand the research capability of the Expedition 45 and 46 crew members aboard the orbiting laboratory.

Orbital ATK has three CRS missions scheduled in 2016 to support NASA's ISS cargo needs. A second Cygnus/Atlas V launch will take place next spring from Florida, followed by the return of operations to NASA's Wallops Flight Facility in mid-2016 where the company will continue CRS missions atop the upgraded Antares rocket.

Under the CRS contract with NASA, Orbital ATK will deliver approximately 62,000 pounds (28,000 kilograms) of cargo to the ISS over 10 missions through 2018. The partnership is changing the way NASA does business, helping build a strong American commercial space industry and freeing the agency to focus on developing the next-generation rocket and spacecraft that will enable humans to travel farther in space than ever before.

Live coverage of the launch and ISS berthing will be available on NASA Television