December 8, 2015 – A United Launch Alliance (ULA) Atlas V rocket carrying the OA-4 Cygnus resupply spacecraft to the International Space Station (ISS) lifted off from Space Launch Complex-41 December 6 at 2:44 p.m. MST. At just over 8 tons, Cygnus is the heaviest payload to launch atop an Atlas V rocket.
The mission, flown for Orbital ATK under NASA’s Commercial Resupply Services contract, marks the first time the Cygnus has flown on an Atlas V rocket. Like most Orbital ATK spacecraft, Cygnus is compatible with multiple launch vehicles. This capability, combined with the flexibility of ULA’s Atlas V, enabled Orbital ATK to carry out the mission to be responsive to NASA’s ISS logistics requirements.
“In the 12 months since this launch was ordered, the ULA and Orbital ATK teams worked very closely together to integrate the Cygnus with the Atlas launch system, including development of a new structural adapter and also a mission design that includes a 30-minute launch window for this ISS rendezvous mission,” said Jim Sponnick, ULA vice president, Atlas and Delta Programs.
Following a 21-minute ascent, the “S.S. Deke Slayton II” Cygnus spacecraft was successfully deployed into its intended orbit approximately 144 miles above the Earth, inclined at 51.6 degrees to the equator. Orbital ATK’s engineering team confirmed that reliable communications had been established and that the vehicle’s solar arrays were fully deployed, providing the necessary electrical power to operate the spacecraft.
“Partnering with Orbital ATK to launch the Cygnus resupply vehicle to the ISS for NASA, a first for ULA, marks a great achievement for the team, and has provided a critical service to the nation and to the crew on the ISS,” said Sponnick. “This mission is delivering more than 7,000 pounds of cargo including supplies for the crew and critical materials supporting science and research investigations.”
The mission is Orbital ATK’s fourth cargo delivery flight to the ISS, but the first flight of an enhanced Cygnus spacecraft. The cargo freighter now features a greater payload capacity, new UltraFlex solar arrays and new fuel tanks. Cygnus’ pressurized cargo module has been extended, enabling the spacecraft to carry over 50 percent more cargo than the previous version.
Science payloads being carried to the ISS will support science and research investigations that will occur during the space station’s Expeditions 45 and 46, including experiments in biology, biotechnology, physical science and Earth science — research that impacts life on Earth. Investigations will offer a new life science facility that will support studies on cell cultures, bacteria and other microorganisms, a microsatellite deployer and the first microsatellite that will be deployed from the space station, and experiments that will study the behavior of gases and liquids and clarify the thermo-physical properties of molten steel and evaluations of flame-resistant textiles. Cygnus is also carrying the Laboratory for Atmospheric and Space Physics’ MinXSS CubeSat, built by students at the University of Colorado, as well as specialized fire extinguishers for the ISS that were developed at the Colorado School of Mines.
The Cygnus spacecraft will be grappled at approximately 4:10 a.m. MST on Wednesday, December 9, by Colorado astronaut Kjell Lindgren, using the space station’s Canadarm2 robotic arm to take hold of the spacecraft. Scott Kelly of NASA will support Lindgren in a backup position. The spacecraft will spend approximately 50 days attached to the space station, before its destructive re-entry into Earth’s atmosphere, disposing of more than 3,000 pounds of trash.
Orbital ATK’s composite structures and solid rocket motors supported the launch of the ULA Atlas V rocket. Orbital ATK contributions include a 10-foot diameter composite heat shield on the launch vehicle, manufactured using advanced fiber placement manufacturing techniques at Orbital ATK’s Luka, Mississippi, facility. This was the 60th ULA Atlas V launch using Orbital ATK-built composite structures.
In addition, this flight marked the 25th successful flight of the Orbital ATK retro motors on the Atlas V, eight of which provided thrust for separation of the spent first stage. The retro motors are built at Orbital ATK’s Elkton, Maryland facility.
This was ULA’s 12th launch in 2015. ULA’s next launch is the GPS IIF-12 satellite for the U.S. Air Force, scheduled for February 3, 2016, from Space Launch Complex-41 at Cape Canaveral Air Force Station, Florida.
Another Cygnus mission on an Atlas V will be launched in March 2016.
Orbital ATK’s upgraded Antares launch vehicle remains on schedule for a full-power hot-fire test in early 2016 and resumption of flight operations from the Wallops Flight Facility in eastern Virginia in the second quarter of the year.