The Cygnus solar array fails to activate
WASHINGTON — NASA is weighing whether it is safe for the Northrop Grumman Cygnus cargo spacecraft to approach the International Space Station after one of its two solar arrays failed to activate hours after its Nov. 7 launch.
The Cygnus spacecraft, flying on mission NG-18 for NASA, was scheduled to deploy its two circular UltraFlex solar arrays about three hours after an Antares rocket launch from Virginia. The arrays produce 3.5 kilowatts of power for the spacecraft.
However, in a statement released more than six hours after launch, NASA said only one of the two solar arrays had been deployed. “Northrop Grumman is collecting data on the deployment of the second array and is working closely with NASA,” the agency said.
According to a NASA statement, Northrop said Cygnus has enough power to rendezvous with the station as planned early on Nov. 9, allowing the station’s robotic arm to grab and attach it. NASA said it was “evaluating” the information.
“It had an array that didn’t deploy, so Northrop Grumman is working right now to get it deployed, and of course we’re evaluating capture and docking in case it doesn’t deploy,” said Dina Contella, operations integration division manager for the ISS to NASA, at a previously scheduled Nov. 7 briefing on a series of upcoming spacewalks on the station.
She stated that the series is going through stages of implementation. “The team is trying to evaluate the data they have and figure out their next steps,” she said, with Northrop leading that effort.
If the array doesn’t start before Cygnus arrives at the ISS, Contella said the station’s program would like to better understand the state of the array before continuing with imaging. “If it ends up partially deployed, it could shake after a catch or landing, or it could open,” she said. “Those are the kinds of things and risk assessments we’ll be doing, if necessary, as we get closer.”
She added that it’s possible that Cygnus could wander near the station if needed to allow more time to study the solar array problem, though the specifics of how long it can do so depends on where NASA and Northrop decide to keep it. “I’m pretty hopeful we’ll deploy a second run.”
While the solar arrays on past Cygnus missions deployed normally, a larger version of the arrays suffered a problem on NASA’s asteroid mission Lucy launched in October 2021. One of the two circular arrays failed to fully deploy and lock into place shortly after launch. Engineers spent months studying the problem and made several efforts to fully implement the array, which made some progress but failed to get the string hooked. NASA said in June that while not fully deployed, the array was stable and would produce enough power for the spacecraft.
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