On July 15 after sending almost two months, Cygnus cargo spacecraft left the International Space Station (ISS), it was sent with supplies and science equipment for a six-person crew of the station.
The uncrewed Cygnus OA-9 spacecraft, also called as the “S.S. J.R. Thompson,” from the ISS it departed at 8:37 a.m. EDT (1237 GMT), it was set free with the help Canadarm2, a 58-foot (18 meters) robotic arm and its controlled from inside the ISS by the astronauts, European Space Agency astronaut Alexander Gerst and NASA astronaut Serena Auñón-Chancellor set it free
For the next two weeks, it is going to remain in low orbit of Earth so that they can place six small satellites known as CubeSats with the help of external NanoRacks CubeSat Deployer. After doing this, it will deorbit and fall toward Earth, and somewhere above Pacific, it will burn up in the atmosphere.
It was Built and launched by Northrop Grumman Innovation Systems (NGIS) —that is a private aerospace manufacturing company formerly known as Orbital ATK —on may 21 the Cygnus OA-9 spacecraft was lifted off on an Antares rocket which is from NASA’s Wallops Flight Facility in Wallops Island, Virginia.
On may 24 it finally reached the ISS and it carries 7,385 lbs. (3,350 kilograms) of science experiments, food, clothing and hardware and other supplies for the crew of six-person of Expedition 55. But payload of the mission wasn’t the only thing it provided to the space station —one last parting gift was given by the Cygnus before starting its journey back to Earth,- an orbital boost that increased the altitude of the station.
While the Cygnus was still docked at the space station’s Unity module on Tuesday (July 10), the spacecraft fired its main engine for 50 seconds as part of a test to determine whether the cargo ship can be used to raise the space station’s orbit, Frank DeMauro, Vice President of Advanced Programs at NGIS, told Space.com
The size of the Cygnus is similar to a short bus, the Cygnus may look little small in comparison with the ISS, which is largely just like a football field. But it is able to raise the orbit of the station to almost 282 feet(86) metres because of its powerful Delta-V engine which is able to provide sufficient thrust. “The burn went extremely well,” DeMauro said. “The spacecraft behaved exactly as we expected.”
“We have several thrusters on the spacecraft that we use for controlling the spacecraft, but we have one big engine that we use … to actually raise our orbit from where the Antares rocket left us off up to the station’s orbit,” DeMauro said. “So, we looked at that and said, that engine has enough thrust and is very efficient, and we could use that engine while we were attached to the space station as a way to provide a boost to the station orbit.”
On July 15, 2018, the Cygnus OA-9 cargo spacecraft slowly shifts off from the International Space Station on, when it will get released from the Canadarm2 robotic arm
The ISS already has a find a way to raise its own orbit with the help of onboard thrusters, but “right now all the orbit raising is done by the Russian side of the space station,” DeMauro said. Aside from the Russian thrusters, Russia’s Progress cargo spaceships can also boost the space station’s orbit. On July 10 when the Cygnus raised the orbit of the station, it became U.S. spacecraft to boost the orbit of the ISS since 2011 when the space shuttles got retired.
“It would be of NASA’s interest for them to have the capability by Cygnus so that we could be either a backup capability or a complementary capability to what the Russians already do,” DeMauro said.
On average, the ISS orbits around Earth at an altitude of about 248 miles (400 kilometres). But it slows down because of little drag by the atmosphere, which lowers to its altitude to nearly 1.2 miles (2km)per month.
Being able to boost the space station’s altitude not only keeps it from falling out of space, but the same technology can be used to help the ISS steer clear of orbital debris, to put the ISS in a good position to rendezvous with arriving vehicles and even to eventually deorbit the ISS. But doing those things would require new modifications to the Cygnus spacecraft, DeMauro said. The main aim to build the cargo ship is to raise the orbit of the space station t, and the OA-9 is the first Cygnus who accomplish its target (and succeeded).
The S.S. J.R Thompson is the ninth of 11 cargo resupply missions NGIS (formerly Orbital ATK) has launched for NASA under a contract of $2.9 billion. In November another Cygnus, OA-10, is programmed to launch to the ISS.