Orbital ATK's Cygnus cargo spacecraft named S.S. Deke Slayton II, performed a safe re-entry into the Earth's atmosphere over the Pacific Ocean, as planned at about 11 a.m. EST on Saturday, Feb. 20, marking a successful conclusion of the OA-4 mission to resupply and support the International Space Station (ISS).
Expedition 46 astronauts Scott Kelly and Tim Kopra of NASA commanded the Canadarm2 robotic arm on the ISS to release the Cygnus spacecraft at 7:26 a.m. EST on Friday, while the space station was flying above Bolivia. Earlier, ground controllers at NASA’s Johnson Space Center had maneuvered Cygnus into place for its departure.
"There was a separation of the cargo ship from the port Unity (Node1) at the U.S. segment of the ISS. After that, the cargo ship was withdrawn in the normal mode to a safe distance from the station and was disconnected from the robot arm," the Russian Mission Control Center (MCC) announced.
Once the spacecraft was a safe distance from the station, its engines were fired twice, pushing it into Earth’s atmosphere where it burned up over the Pacific Ocean.
The Cygnus resupply craft arrived to the space station on Dec. 9, following Dec. 6 launch on a United Launch Alliance Atlas V rocket from Cape Canaveral Air Force Station in Florida, for the company’s fourth NASA-contracted commercial station resupply mission.
Experiments delivered on Cygnus supported NASA and other research investigations during Expeditions 45 and 46, in areas such as biology, biotechnology, and physical and Earth science — research that impacts life on Earth. The Cygnus was also filled with trash and discarded gear over the last few days before the hatches were closed Thursday.
The OA-4 mission marked the Return to Flight mission for Orbital ATK after the October 2014 Antares launch failure in which the original S.S. Deke Slayton was lost.