Astronauts aboard the International Space Station carried out a robot arm-capture of Orbital Sciences’s Cygnus supply capsule early Sunday, following a successful unpiloted rendezvous with the six-person orbiting science laboratory.
Astronaut Luca Parmitano, of the European Space Agency, was at the controls as the Canadian robot arm reached below the ISS to grapple Cygnus at 7a.m., EDT. NASA astronaut Karen Nyberg assisted as the freighter was nabbed at a range of 12 meters.
Sunday’s capture closed out the delayed rendezvous phase of Orbital’s final demonstration flight under NASA’s Commercial Orbital Transportation Systems program, a $288 million-, 5 1/2-year effort to qualify the Dulles, Va.,-based company to begin a $1.9-billion, eight-flight commercial resupply services agreement. Orbitals's CRS contract was signed in late 2008, and the first cargo delivery under the agreement is tentatively slated for December.
“Cygnus capture complete,” radioed Parmitano.
“We see a good capture down here,” responded NASA’s Mission Control. “Looks great.”
Orbitals's Cygnus resupply capsule in grasp of ISS robot arm. Photo Credit: NASA TV
Parmitano and Nyberg maneuvered Cygnus and its 1,543-pound cargo of crew provisions to a berthing with the station’s U.S. segment Harmony module at 8:44 a.m., EDT, well ahead of schedule. Station astronauts will open the freighter early Monday.
The COTS 10 objective-demonstration mission was launched aboard an Orbital two-stage Antares rocket from the Mid-Atlantic Regional Spaceport on Virginia’s Eastern shore on Sept. 18. Plans for a Sept. 22 rendezvous with the ISS and capture were delayed by a mismatch in GPS navigation timing data between the two spacecraft that was discovered just hours before the scheduled encounter.
That was followed by a second extended postponement on Sept. 23 to permit Russia’s Soyuz TMA-10M to launch and deliver three new ISS crew members late Sept. 25. A one-line software patch correcting the mismatch was uploaded and verified during the postponement.
Cygnus is to remain berthed to the ISS until Oct. 22, permitting a measured transfer of the clothing, food, office supplies, spare parts and a collection of student Nanoracks experiments to the station and a re-stowing of the freighter with trash.
Sunday’s rendezvous activities unfolded with few difficulties, allowing Orbital to close out eight of 10 COTS flight objectives. Short conferences between the ISS crew and NASA’s Mission Control, however, followed to remedy an erroneous rendezvous and proximity operations computer display on the station, intermittent loss of signal displays from NASA’s Tracking and Data Relay communications satellite prior to the capture as well as the final grapple status indication.
Unpiloted Cygnus moves within 17 meters of the ISS. Photo Credit: NASA TV
The 10th objective, a single rendezvous laser reflector demonstration at just beyond 55 meters, followed a successful exercise in which Parmitano commanded Cygnus to advance from a 250 meter hold point below the station to a range of 230 meters, where it held for several minutes then retreated to 250 meters.
After demonstrating the crew could avert a potential collision threat, Cygnus was commanded to advance to a range of 30 meters for the last of five “go/no go” conferences between NASA’s Mission Control and Orbital’s ground control team in Virginia.
As the month long flight concludes with a departure and destructive re-entry into the Earth’s atmosphere, Orbital will join SpaceX, of Hawthorne, Calif., as the second U.S. commercial space station resupply service. NASA established the COTS program to take on some of the duties once provided by NASA’s retired space shuttle fleet.
SpaceX, which carried out a similar COTS demo in May 2012, is tentatively scheduled to launch its third cargo delivery mission early next year. SpaceX also signed its 12-flight, $1.6-billion CRS agreement in December 2008.