Cygnus Resupply Vehicle Temporarily Undocked to Clear Path for Soyuz Crew Arrival

The Northrop Grumman Cygnus XL resupply vehicle, designated as part of the NG-23 mission, executed a temporary undocking from the International Space Station (ISS) on November 26, 2025. This precise orbital maneuver was coordinated by NASA, Northrop Grumman, and Roscosmos to ensure the approach corridor remained clear for the Soyuz MS-28 crewed spacecraft, which is scheduled for launch the following day, November 27, 2025.

The Cygnus XL, named S.S. William "Willie" C. McCool, is currently secured by the Canadarm2 robotic arm, with its reattachment planned for December 1, 2025. The NG-23 mission, launched on September 14, 2025, from Cape Canaveral’s SLC-40 aboard a SpaceX Falcon 9 Block 5 rocket, introduced the larger Cygnus XL configuration. This variant features a pressurized cargo module 7.89 meters long, increasing payload capacity by 19.5 percent to approximately 5,000 kilograms of supplies and scientific hardware delivered on September 18.

The relocation was necessary because the Cygnus XL’s berthing port on the Unity module would obstruct the trajectory for Soyuz MS-28, which is slated to dock with the adjacent Rassvet module. The complex operation was managed by the robotics officer at NASA's Johnson Space Center Mission Control Center in Houston, with monitoring provided by Expedition 73 crew members, NASA astronauts Jonny Kim and Zena Cardman. The 17-meter-long Canadarm2 performed the detachment and is maintaining the cargo craft in a secure holding pattern.

The Soyuz MS-28 mission, set for a November 27 launch from Baikonur Cosmodrome’s Site 31/6, will transport crew members including NASA astronaut Chris Williams and Roscosmos cosmonauts Sergey Kud-Sverchkov and Sergey Mikaev for an eight-month research tenure. The successful temporary relocation of the Cygnus XL ensures that the arrival sequence for the crewed vehicle proceeds without trajectory conflicts with the already berthed cargo craft.

During its tenure, the NG-23 Cygnus XL delivered investigations concerning semiconductor crystal production, microgravity's effect on biofilm prevention, and equipment for cryogenic fuel tank improvements. Astronaut Zena Cardman conducted a fluid physics experiment involving gas injection to sustain cryogenic fluids, while Jonny Kim utilized the advanced resistive device for the CIPHER study on cardiorespiratory fitness in microgravity. Following the Soyuz docking, the Cygnus XL is scheduled for reattachment to the Unity module on December 1, where it will remain until at least March 2026 before performing a deorbit burn with station waste.