An . Cygnus cargo carrier will remain berthed to the International Space Station (ISS) for as long as 45 days, after station crew members used their robotic arm to snatch it from a holding position early Wednesday and berth it to the station’s Harmony node.
"Janice Voss is now part of Expedition 40," radioed’s Steve Swanson after he grappled the 5.1-meter-long Cygnus, which is named for the late shuttle astronaut and Orbital Sciences engineer.
Orbited by an Antares launch vehicle that lifted off from Wallops Island, Virginia, on Sunday, the Cygnus carried almost 3,300 lb. of food, clothing and supplies for the crew, along with 32 cubesats that will be jettisoned later from the "porch" of Japan’s Kibo module, and other spaceflight gear.
astronaut Reid Wiseman used a laptop controller to drive home 16 motorized bolts that sealed it to the Harmony hatch for unloading.
If all goes as planned, the Cygnus will remain there until Aug. 15, although it can stay until the end of August if the heavy traffic flow of arriving vehicles makes it necessary.
"They’ve got quite a problem they’re having to deal with in terms of so many vehicles coming," said Frank Culbertson, a former ISS commander who heads Orbital’s Advanced Programs Group. "It’s a good problem. But we will stay up there as long as necessary to fill the cargo module with as much disposable cargo as possible, and then reenter about five days after we finish closing the hatch and leaving the station."
The company plans to use the extra time on orbit to evaluate its performance as a free-flyer where potentially hazardous experiments can be teleoperated, and to validate a new reentry profile designed to save fuel while ensuring that the aluminum vehicle and its load of trash burn up completely on reentry, he said.
"We want to be able to fly Cygnus for extended periods after it leaves the station and conduct experiments for other users," Culbertson said before the launch. "There are NASA centers that want to conduct other experiments, and the longer we can stay in space the better. So we’re looking at ways to ensure that we understand the most efficient operation of the spacecraft once it leaves the station."
The mission was delayed by about two months after an AJ-26 engine destined for a later Antares launch failed during a May 22 acceptance test at Stennis Space Center. Ultimately visual inspection with borescopes cleared the two engines on the Antares that launched July 13, but NASA’s human-spaceflight chief said the delay added to the importance of Wednesday’s delivery.
"I think this next year will be really important to us if we kind of establish a cadence of routine flights," William Gerstenmaier, associate administrator for human exploration and operations, said after the launch. "And that’s not easy. We’ve got a little margin so we can grow and not push too hard, but we need to get into kind of a cadence where we’re flying regularly."
Orbital is scheduled to deliver 20,000 kg (44,000 lb.) of cargo to the ISS under its eight-flight, $1.9 billion Commercial Resupply Services (CRS) contract with NASA.is down for a similar load under a separate CRS contract that also includes down-mass recovery at sea via its Dragon capsule. The station also receives supplies for its six-person crew from Europe’s Automated Transfer Vehicle, with one more scheduled to fly; Japan’s H-II Transfer Vehicle, and Russia’s Progress cargo-carrier.