While NASA astronaut Scott Kelly and his Russian colleague, cosmonaut Mikhail Kornienko, have returned to Earth after a year on the International Space Station, work goes on aboard the orbiting outpost. To keep supplies coming to the current ISS crew and those who soon will join them, an Orbital ATK Cygnus spacecraft is being prepared at NASA’s Kennedy Space Center in Florida.
Members of the news media recently were given an opportunity to visit the spaceport’s Payload Hazardous Servicing Facility, or PHSF, where Cygnus is being prepared.
The Orbital ATK Commercial Resupply Services-6 mission is scheduled for launch at 11:05 p.m. EDT on March 22 atop a United Launch Alliance Atlas V rocket. Liftoff will take place at Space Launch Complex 41 at Cape Canaveral Air Force Station.
Former astronaut Dan Tani, now senior director of Missions and Cargo Operations for Orbital ATK in Dulles, Virginia, spoke about what he recalls about a resupply spacecraft arriving at the ISS. He was a member of the station’s Expedition 16 crew from October 2007 to February 2008.
“It’s like Christmas,” he said. “It’s exciting to watch another vehicle approach and dock. It’s like opening a big box of goodies and finding some stuff that you’ve been wanting and finding some surprises you didn’t know about.”
Orbital ATK uses the Cygnus to ferry provisions to the ISS under NASA’s Commercial Resupply Services contract.
Cygnus consists of a pressurized cargo module for crew supplies, scientific experiments and equipment, together with an associated service module providing solar power and propulsion, to deliver approximately 7,700 pounds of cargo to the station.
This mission will be the second flight of the enhanced variant of Orbital ATK’s Cygnus spacecraft. The upgraded cargo freighter features a greater payload capacity, new solar arrays and new fuel tanks. Cygnus’ pressurized cargo module has been extended and increases the spacecraft’s interior volume capacity by 25 percent, enabling more cargo to be delivered with each mission.
According to Tani, Orbital ATK’s CRS-4 mission went so well, no significant changes were made for CRS-6.
“We had a great mission on CRS-4, he said “There were a few workarounds we needed to do, but it was so minor we didn’t make any changes to this (CRS-6) vehicle.”
Tani explained that the astronauts aboard the orbiting outpost play a crucial role in commanding the spacecraft to get it into the right position so they can capture, or grapple, it with the station’s robotic arm.
“The crew on board the station get involved about two hours before they actually grapple Cygnus,” he said. “Their job is to watch the vehicle as it’s coming in and command the Cygnus to go into free-drift. This means it cannot control itself. That way, when they do grapple it, the spacecraft won’t be fighting the force of the arm.”
Plans call for the Cygnus spacecraft to remain attached to the station for about a month. Before undocking, the spacecraft will be loaded with several thousand pounds of trash prior to its destructive re-entry into Earth’s atmosphere.