WASHINGTON — Ceding priority to a Soyuz spacecraft scheduled to fly three crew members to the international space station Sept. 25, Orbital Sciences Corp. has postponed the berthing of its Cygnus spacecraft with the outpost until Sept. 28 at the earliest.
Cygnus, which has been in space since Sept. 18, was originally scheduled to berth with the station Sept. 22, but a miscommunication between the spacecraft and the station prompted the company and NASA to reschedule Cygnus’ arrival for Sept. 24. However, on the morning of Sept. 23, Orbital wrote on its website that Cygnus’ arrival would again be delayed to make room for an inbound Soyuz crew capsule.
“This morning, Orbital and NASA together decided to postpone the approach, rendezvous, grapple and berthing operations of the Cygnus cargo logistics spacecraft with the International Space Station until after the upcoming Soyuz crew operations are complete,” the company wrote on its website.
As for the communications glitch discovered Sept. 22, Orbital believes it can be fixed with a software update, which the company was readying Sept. 22 to transmit to the orbiting Cygnus Sept. 23.
Early on the morning of Sept. 22, “Cygnus established direct data contact with the [international space station] and found that some of the data received had values that it did not expect, causing Cygnus to reject the data,” Orbital wrote. “This mandated an interruption of the approach sequence.”
Orbital spokesman Barron Beneski could not immediately be reached for comment the morning of Sept. 23.
Cygnus was launched Sept. 18 by its Antares carrier rocket from the Mid-Atlantic Regional Spaceport, a state-operated facility at NASA’s Wallops Flight Facility in Virginia.
Cygnus is carrying a cache of noncritical cargo as part of a demonstration mission that, if successful, will clear the way for Orbital to begin routine deliveries under an eight-flight, $1.9 billion Commercial Resupply Services contract it signed with NASA in 2008. After a 30-day stay at the space station, the expendable Cygnus will detach from the station, re-enter the atmosphere and burn up over the Pacific Ocean.
Assuming the rest of the mission goes smoothly, a NASA official said, Orbital could be approved to begin contracted cargo deliveries not long after the ongoing demonstration mission ends.
“We will get a final report from Orbital a few days after the end of the mission, which is going to be at the end of October now,” NASA’s Alan Lindenmoyer, manager of the agency’s Commercial Crew and Cargo Program Office, said during a Sept. 18 post-launch press briefing from Wallops.
Orbital Sciences stands to be the second to deliver cargo to the space station under NASA’s Commercial Resupply Services contract. The first, Space Exploration Technologies Corp., flew its own demonstration mission in May 2012 and has since flown two of the 12 flights it owes NASA under a $1.6 billion contract.