Live coverage: SpaceX to launch new, improved Northrop Grumman Cygnus XL resupply ship to the space station

The next cargo resupply mission to the International Space Station is launching Sunday and will feature a new iteration of the Cygnus spacecraft from Northrop Grumman.

The mission, NASA’s NG-23, is the latest flight fulfilling NASA’s Commercial Resupply Services-2 contract with Northrop Grumman. The Cygnus XL spacecraft making its debut is capable of carrying 33 percent more cargo than the previous version of the Cygnus vehicle.

SpaceX is scheduled to launch the cargo craft atop a Falcon 9 rocket from pad 40 at Cape Canaveral Space Force Station at 6:11 a.m. EDT (2211 UTC).

Spaceflight Now will have live coverage beginning about 90 minutes prior to liftoff.

It will be the fourth flight of the Falcon 9 first stage booster, B1094, which entered service in April this year, previously launching the Starlink 12-10, Axiom Mission 4 and Crew-11 missions.

A little less than eight minutes after liftoff, B1094 will return to Cape Canaveral for a touchdown at Landing Zone 4. This will be the 14th booster recovery at that site and the 505th landing for SpaceX to date.

The Cygnus will separate from the Falcon 9 upper stage 14 and a half minutes into the flight to begin its solo journey to the ISS. The cargo freighter is scheduled to be captured and berthed to the space station on Wednesday, Sept. 17, at 6:35 a.m. EDT (1035 UTC).

Cygnus evolves

The debut of the Cygnus XL comes on the 23rd flight of a Cygnus spacecraft to date. It’s designed to carry 33 percent more cargo to the space station than previous iterations of the vehicle.

“It’s really critical because we can deliver significantly more science as well as we’re able to deliver a lot more cargo prelaunch, really trying to drive down the cost per kilogram to NASA,” said Ryan Tinter, vice president of Civil Space Systems for Northrop Grumman.

“As we’re setting up for the future of commercial [low Earth orbit], we’re trying to make sure that we are ready with these kind of commercial and economic options to get a lot of capability and a lot of equipment into space.”

This particular flight features more than 11,000 pounds (4,990 kg) of food, science and supplies. The spacecraft is set to stay docked to the space station nominally until around March 2025.

Because of its increased size, Cygnus will be briefly unberthed from the space station using the outpost’s robotic arm during the approach and docking of a crewed Russian Soyuz craft on Nov. 27.

“Cygnus is berthed to node one nadir and that’s close to the corridor for Soyuz rendezvous,” Dina Contella, the deputy manager of NASA’s ISS Program, explained during a prelaunch briefing. “So, when Soyuz is coming into dock at the SUV MRM (Mini-Research Module) one port, we’d like for safety’s sake to unberth Cygnus and hold it away from the Russian segment.”

Alternatively, mission managers might decide to fill the module with as much trash as possible and release it before the arrival of Soyuz MS-28, she said.