Northrop Grumman’s Cygnus On Its Way to ISS, But With a Stuck Solar Array

Northrop Grumman successfully launched its Cygnus cargo spacecraft to the International Space Station this morning, but one of the two solar arrays did not deploy. The company is troubleshooting the problem while NASA assesses what issues could arise when berthing Cygnus to ISS in that condition. Cygnus is carrying equipment needed for a spacewalk next week, so those plans could change if berthing is not possible.

The launch today is the 18th Cygnus mission to ISS, NG-18, under NASA’s Commercial Resupply Services procurement. Liftoff was delayed a day because a fire alarm went off at Northrop Grumman’s Mission Control Center in Dulles, VA at a crucial point in Sunday’s countdown.

They had better luck today, launching at 5:32:42 am ET.

After the successful launch and Cygnus’s separation from the rocket, NASA revealed that one of the two solar arrays did not deploy, however. The circular arrays provide electrical power to the spacecraft.

After launching earlier today, Nov. 7, Northrop Grumman’s Cygnus cargo spacecraft has successfully deployed one of its two solar arrays. Northrop Grumman is gathering data on the second array deployment and is working closely with NASA.

Northrop Grumman has reported to NASA that Cygnus has sufficient power to rendezvous with the International Space Station on Wednesday, Nov. 9, to complete its primary mission, and NASA is assessing this and the configuration required for capture and berthing. We will provide more information as it becomes available. — NASA

At a news conference this afternoon about upcoming spacewalks at the ISS, NASA’s Dina Contella, ISS operations integration manager, confirmed that the recalcitrant array had not deployed at all.

She expressed confidence that Northrop Grumman will solve the problem before Cygnus arrives at the ISS early Wednesday morning, but NASA is taking a look at options if not.

Cygnus does not dock with the ISS, but berths to it. That means the astronauts on the ISS use the robotic Canadarm2 to capture or “grapple” Cygnus. Ground controllers then take control of the arm and install the spacecraft onto a docking port.

Contella said one concern is what might happen during that process. “So if [the array] ends up partially deployed, then, you know, it could jiggle upon capture or berthing or it could come open. So those are the types of things and risk assessment that we’ll be doing if necessary.”

Cygnus is delivering 8,200 pounds of science investigations and cargo. Among the cargo is a collection of brackets or “modkit” that astronauts Josh Cassada and Frank Rubio are supposed to set up on a November 15 spacewalk, the first of three related to installing new ISS Roll Out Solar Arrays (iROSAs) to augment the ISS power supply.

If Cygnus can’t berth to the ISS, those plans may have to change.

Northrop Grumman names its Cygnus cargo spacecraft after individuals who have pioneered human spaceflight. This one is named in honor of the late NASA astronaut Sally Ride, the first American woman in space.