Overview

• Liftoff is targeted for 6:11 p.m. EDT from Cape Canaveral’s SLC-40 with a 70% favorable weather forecast for the instantaneous window.
• Northrop Grumman’s Cygnus XL debuts with 33% more volume and up to about 5,000 kg of cargo capacity, flying as the S.S. William C. “Willie” McCool.
• Rendezvous is planned roughly 60 hours after launch, with Canadarm2 capture and berthing to Unity’s nadir port on Sept. 17 at 10:35 UTC operated by NASA astronaut Jonny Kim.
• The manifest includes ISS spares and 15 ISS National Lab payloads, highlighted by TransAstra’s inflatable Capture Bag test in the Bishop Airlock plus studies on UV effects on biofilms, molecular crystallization and in-space fuel storage.
• Cygnus is slated to remain attached into March 2026, temporarily unberthing in November to clear the corridor for Soyuz MS-28 and later deploying CubeSats before a planned destructive reentry.