Cygnus Cargo Ship leaves the space station Sunday: Watch it live

A Cygnus freighter will separate from the International Space Station (ISS) Sunday morning (July 15), and you can watch his departure live online.

The Cygnus OA-9 spacecraft, also known as "SSJR Thompson" arrived at the ISS in May 24 with 7,385 lbs. (3,350 kilograms) of scientific supplies and experiments. He will leave the lab in orbit at 8:35 AM EDT (12:35 GMT) on Sunday, starting a two-week trip that will end with a crazy dive into the Earth's atmosphere. NASA TV will be broadcast live from the ISS at 8:15 am EDT (12:15 GMT), and you can watch it live on Space.com

To send the ship on its way, the astronaut from The European Space Agency Alexander Gerst and NASA astronaut Serena Auñón-Chancellor will use Canadarm2's robotic arm to free him from the space station's Unity module. By hooking to the Cygnus with one of his "hands", the 18-meter (58-foot) robot maneuvers the spacecraft at a safe distance from the ISS and releases it into Earth orbit. low. [Launch Photos: Orbital ATK’s Antares Rocket & Cygnus OA-9 Soar to ISS!]

Instead of going directly to Earth, the Cygnus will spend two weeks flying in space "to allow the Cygnus control team to conduct engineering tests" , NASA officials said. It will also deploy several small satellites called cubesats in orbit with the help of an external deployer built by the Houston-based NanoRacks company. But most of the cargo that Cygnus will remove from the ISS is the trash – "thousands of pounds," according to NASA officials.

On July 30th, S / Sgt Thompson will complete his mission and will desorb, falling to Earth and burning in the atmosphere along the way. However, there is no need to worry about falling debris. If pieces of the spacecraft manage to survive the fall, they will fall safely into the Pacific Ocean, NASA officials said.

The Cygnus freighters and Antares rockets launching them into space are built by Northrop Grumman Innovation Systems (formerly Orbital ATK), a private company that NASA contracted to transport cargoes to the ISS after the end of the space shuttle program in 2011. NASA also asked SpaceX to do the same with its Dragon spacecraft and its Falcon 9 rocket.

While the Cygnus and the Dragon both serve the same purpose of deliver cargo to the ISS, the Cygnus has recently acquired a new capability that the Dragon does not have: he can now use his thrusters to boost the ISS and increase its orbit. The flight controllers successfully tested this new capability for the first time on Tuesday, July 11, said Frank DeMauro, vice president of Northrop Grumman's Advanced Programs Division, at Space.com. (The Advanced Programs Division oversees all Cygnus cargo replenishment missions.)

Because the ISS experiences a small aerodynamic drag in the upper Earth's atmosphere, it slows over time, disintegrating its orbit . The ISS already has the capacity to strengthen itself, but the visit of the Cygnus vehicles can now serve as a backup for the station's own built-in thrusters. On average, the ISS orbits around the Earth at an altitude of 400 km (248 miles) and the Cygnus test has raised it to 86 meters (282 feet). "The burn has gone very well," DeMauro said. DeMauro said that Cygnus vehicles could in the future be used to lower the orbit of the space station – or even to fully desorb the ISS, pushing it down into the sky. atmosphere where it would burn just like the SSJR Thompson will do on July 30th.

Email Hanneke Weitering at [email protected] or follow her @hannekescience . Follow us on @Spacedotcom Facebook and Google+ . Original article on Space.com .