Cygnus supply ship departs space station after four-month mission

Northrop Grumman’s Cygnus supply ship is released from the International Space Station’s robotic arm at 12:32 p.m. EDT (1632 GMT) Tuesday. Credit: NASA TV/Spaceflight Now

A Cygnus spacecraft owned by Northrop Grumman departed the International Space Station Tuesday, concluding a four-month mission that delivered more than 8,000 pounds of cargo. The automated resupply freighter will deploy five small CubeSats before re-entering the atmosphere and burning up over the Pacific Ocean.

Ground controllers commanded the space station’s Canadian-built robotic arm to release the Cygnus spacecraft at 12:32 p.m. EDT (1632 GMT) Tuesday as the complex sailed 270 miles (434 kilometers) above Wyoming.

NASA astronaut Megan McArthur monitored the spacecraft’s departure from inside the space station.

The Cygnus spacecraft arrived at the space station Feb. 22, two days after launching on an Antares rocket from Wallops Island, Virginia. After capturing the Cygnus spacecraft, the robotic arm maneuvered the ship to the nadir, or Earth-facing, port on the space station’s Unity module.

Northrop Grumman named the Cygnus supply ship the S.S. Katherine Johnson in honor of the NASA mathematician portrayed the film “Hidden Figures.”

The spacecraft delivered to the space station new astronaut sleeping quarters, parts for the outpost’s toilet, and numerous biomedical and technology experiments.

The mission, designated NG-15, marked the 15th cargo delivery to the space station by a Cygnus spacecraft since 2013. After unpacking 8,400 pounds (3,810 kilograms) of equipment inside the craft’s pressurized cabin, astronauts loaded about 7,180 pounds (3,256 kilograms) of trash into the freighter for disposal, a NASA spokesperson said.

Northrop Grumman’s Cygnus spacecraft, named the S.S. Katherine Johnson, is seen berthed to the International Space Station in March. Credit: NASA

The astronauts also installed CubeSats onto a rail deployer on the Cygnus hatch before the robotic arm removed the freighter from the Unity berthing port.

After flying a safe distance from the space station and climbing into a higher orbit, the Cygnus spacecraft will deploy five small nanosatellites.

The Gunsmoke-J technology demonstration satellite is a 3U CubeSat for the U.S. Army Space and Missile Defense Command, which aims to prove the usefulness of an Earth-imaging payload for tactical use by military combat troops.

“This science and technology effort will provide new and advanced capabilities to the tactical warfighters in a small satellite that is about the size of a loaf of bread,” the Army said in a press release last year. “The effort will also help inform future acquisition decisions.”

The Gunsmoke-J satellite and two other small satellites for unspecified U.S. government customers launched inside the Cygnus spacecraft’s pressurized module in February, then were mounted on the Slingshot deployer on the craft’s forward hatch by the space station crew.

The Army’s first Gunsmoke-J tech demo satellite launched in March on a Rocket Lab Electron rocket. This will be the second unit to deploy into orbit.

A Gunsmoke-J satellite. Credit: U.S. Army

Spaceflight, the Seattle-based rideshare launch broker, arranged launch services for the Gunsmoke-J and the two other U.S. government satellites.

Two other CubeSats are also aboard the Cygnus cargo freighter for release from a Nanoracks deployer. One is named IT-SPINS, and it will collect images of the ionosphere over the night side of the Earth during a six-month research mission. The IT-SPINS CubeSat, about the size of a toaster oven, was developed at Montana State University.

A CubeSat named DhabiSat will also be released into orbit. The small spacecraft was developed by students at Khalifa University in Abu Dhabi. Students designed and built the CubeSat with help from Yahsat, a communications satellite company in Abu Dhabi, and Northrop Grumman.

Once the CubeSats are deployed, Northrop Grumman’s mission control team will command the Cygnus spacecraft to perform a deorbit burn to burn up during re-entry over the Pacific Ocean on Thursday.

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