Northrop Grumman’s new Cygnus XL spacecraft will not dock with the International Space Station (ISS) as initially scheduled for Wednesday morning. In a blog post released on Tuesday evening, NASA announced that two orbit-raising burns of the spacecraft’s main engine “stopped earlier than planned.” The agency did not disclose how much of the planned burns were completed before the premature shutdowns, nor did it provide information on the potential causes of the engine’s unexpected performance.
As mission managers assess plans to execute the remaining rendezvous maneuvers, NASA reassured that “all other Cygnus XL systems are performing normally,” but further details remain undisclosed. Originally, NASA astronaut Jonny Kim was set to capture the Cygnus XL spacecraft at 6:35 a.m. EDT (10:35 UTC) with the assistance of fellow NASA astronaut Zena Cardman. Kim’s role involves commanding the Canadarm2 robotic arm to secure the spacecraft when it is approximately 10 meters (32.8 ft) from the ISS.
The Cygnus XL spacecraft, named the S.S. William ‘Willie’ C. McCool, launched from pad 40 at Cape Canaveral Space Force Station aboard a SpaceX Falcon 9 rocket at 6:11 p.m. (22:11 UTC) on Sunday, September 14. The cargo ship successfully separated from the rocket’s upper stage more than 14 minutes after liftoff. NASA reported that the vehicle managed to deploy its two solar arrays roughly an hour and a half after its departure from the space coast.
Just a day before this launch, an uncrewed Russian Progress vehicle arrived at the ISS on a planned cargo supply mission, highlighting the ongoing logistical efforts to support the space station.
This mission, officially known as NASA’s Northrop Grumman Commercial Resupply Services 23 (NG-23), marks the debut of the Cygnus XL spacecraft. As its name implies, the Cygnus XL is a larger version of the previous Cygnus spacecraft, measuring about 1.6 meters (5.2 ft) longer and capable of carrying approximately 2,600 pounds of additional cargo. “It’s got 33 percent more capacity than the prior Cygnus spacecraft had,” noted Ryan Tinter, vice president of Civil Space Systems for Northrop Grumman, prior to the launch. “This increased capacity is critical as it allows us to deliver significantly more science and cargo per launch, ultimately driving down the cost per kilogram for NASA.”
The Cygnus XL is currently transporting over 11,000 pounds (4,990 kg) of vital supplies, including food, scientific equipment, and other essential items. As highlighted by Dina Contella, deputy manager of NASA’s ISS Program, during a prelaunch briefing, “The NG-23 vehicle is packed with consumables, like nitrogen, oxygen, food, and toilet parts, as well as spare parts needed for critical systems.” This mission is particularly crucial as NASA aims to replenish supplies that had been depleted over the previous year.
Earlier this year, NASA had to revise its planned cargo schedule following issues with another Cygnus spacecraft. The vehicle designated for the NG-22 mission was damaged during transport from Northrop Grumman’s facilities in Virginia to NASA’s Kennedy Space Center in Florida. As a result, NASA adjusted the cargo load on SpaceX’s CRS-32 mission to include more consumable supplies to ensure sufficient reserves aboard the ISS. Additionally, NASA expedited the launch schedules for both SpaceX’s CRS-33 and the NG-23 missions to bridge the gap between cargo deliveries.
“Historically, we aim to maintain four months of supplies onboard the ISS. This strategy is vital in case of any delays with upcoming missions,” explained Dana Weigel, manager of NASA’s ISS Program. Following the August 1 launch of the Crew-11 mission, Weigel discussed how the situation with the NG-22 mission led to adjustments in the cargo strategy to ensure continued support for the astronauts aboard the ISS.
Following the planned arrival of the NG-23 Cygnus XL, the next cargo mission on the schedule is the new HTV-X spacecraft, developed by Mitsubishi Heavy Industries with assistance from the Japanese Aerospace Exploration Agency (JAXA). The HTV-X is slated to launch on an H3 rocket from Japan on October 21, further expanding the range of cargo delivery options to the ISS.
Northrop Grumman and SpaceX are currently the two primary U.S. companies responsible for delivering cargo to the ISS under NASA’s Commercial Resupply Services 2 contract. Though both companies have experienced in-flight anomalies during their early missions, they have successfully completed numerous flights, with Northrop Grumman having completed 20 cargo deliveries and SpaceX achieving 31 flights.
In summary, while the Cygnus XL mission has encountered unexpected challenges, NASA and its partners are committed to ensuring the continued supply of essential resources to the ISS, maintaining the momentum of scientific research and exploration in low Earth orbit.
