SpaceX set for Sunday launch to space station with sonic boom in store

SpaceX is lending a hand to fellow commercial cargo company Northrop Grumman once again with a planned launch Sunday evening on the Space Coast to send supplies to the International Space Station that could also bring a sonic boom to parts of Central Florida.

A Falcon 9 rocket is slated to lift off on the NG-23 resupply mission to the ISS with the largest Cygnus spacecraft yet from Cape Canaveral Space Force Station’s Space Launch Complex 40 at 6:11 p.m.

Space Launch Delta 45’s weather squadron forecasts a 75% chance for good launch conditions, which improves to 85% if delayed 24 hours. Backup options for the launch fall to Monday at 5:49 p.m. or Tuesday at 5:23 p.m.

The first-stage booster on the mission if making its fourth trip to space and SpaceX plans to return it back for a land recovery at Canaveral’s Landing Zone 2.

SpaceX warns that depending on weather conditions, one or more sonic booms could be heard in Brevard, Orange, Osceola, Indian River, Seminole, Volusia, Polk, St. Lucie, and Okeechobee counties, although recent land recoveries of boosters have had reports of the boom heard as far as Lake County.

This would be the 78th orbital launch this year on the Space Coast with all but four missions flown by SpaceX.

Called the Cygnus XL, the larger cargo spacecraft will be flying with 11,000 pounds of science, replacement parts, food and other supplies with a planned docking Wednesday morning to the space station when NASA astronaut Jonny Kim will use the Canadarm 2 to grapple it and attach it to the Unity module.

It’s about 5 feet longer with a capacity to carry an additional 2,600 pounds of cargo than previously flown Cygnus spacecraft.

The plan is for it to remain on the station through March 2026. It will be loaded with trash and sent back to burn up in Earth’s atmosphere. There is a chance it could come home earlier depending on how a plan goes to temporarily undock it in December to make room for an incoming Soyuz spacecraft.

On board are some Thanksgiving-themed food supplies but also more than 50 scientific studies for NASA and its partners.

The ISS has for nearly 25 years been continuously crewed and has hosted more than 4,000 science and tech demonstrations supporting more than 5,000 researchers and 110 countries, said Liz Warren, NASA’s associate chief scientist for the ISS Program Research Office.

“The International Space Station is truly a global endeavor and serves as a proving ground for scientific breakthroughs and a critical stepping stone to help enable the Artemis program, lunar exploration and future Mars missions,” she said.

The station’s utility vs. its cost has been a target of late of the Trump administration, which is considering reducing the frequency of crewed visits as well as the number of people flown each time to the station as it winds down its life cycle. The ISS is slated to be decommissioned after 2030 after which NASA wants to rely on commercial space stations for its low-Earth orbit needs while focusing exploration on the moon and Mars.

The mission is the third time SpaceX has been the launch service provider for the Cygnus spacecraft since Northrop Grumman shut down launches of its Antares rocket from Virginia’s Eastern Shore at NASA’s Wallops Flight Facility.

“Regardless of how we deliver the Cygnus spacecraft to orbit, we need to have a launch vehicle so one way or another there is a launch vehicle,” said Ryan Tintner, vice president of Northrop Grumman’s Civil Space Systems.

A Cygnus has also flown once before on a United Launch Alliance Atlas V.

“In fact, what we’ve prided ourselves in is that Cygnus has been able to integrate and fly on a variety of launch vehicles. I think that frankly an important point for space is if there are challenges on any vehicle or if a vehicle’s grounded, our ability to be able to maintain launch on different systems is frankly equally as important as an independent business case,” Tintner said. “If you don’t have the ability to assure customers that you’re going to be able to deliver to orbit regardless of a changing dynamic then you can’t be relied upon.”

Originally SpaceX was called on to provide three stop-gap missions while Northrop Grumman and its partner Firefly Aerospace continue to build a new version of Antares called the Antares 330 that aims to fly in 2026.

Firefly is providing the first stage with American-made engines. The previous Antares rocket used Russian-made engines, and companies had to shift away from that if they wanted to compete for any government missions after an act of Congress. Northrop Grumman and Firefly are also working on a new rocket called Eclipse that would be larger than Antares 330. While initial launches would also be from Virginia, Firefly still has a lease option at Cape Canaveral.

SpaceX and what was formerly Orbital ATK before it was acquired by Northrop Grumman were the two commercial companies to win resupply service contracts to the space station, although a third company, Sierra Space, has since been added, but its Dream Chaser spacecraft has yet to fly a mission.

For Northrop Grumman, this flight, although dubbed NG-23, is the 22nd overall for Cygnus. The NG-22 mission has been delayed until an undetermined date because that mission’s pressurized capsule was damaged during an ocean transit.

For this mission, the NG-23 spacecraft has been named in honor of NASA astronaut Willie McCool, one of the seven killed aboard Space Shuttle Columbia when it broke apart during reentry in 2023 during the STS-107 mission.

For more than 10 years, though, Cygnus has flown more than 150,000 pounds of supplies to the station across 21 missions.

Northrop Grumman will be flying at least one more mission with SpaceX as their ride before switching its upgraded Antares rocket.

“The partnership with SpaceX has been great, so we look forward to continuing kind of close work there even when we’re launching more regularly on the Antares 330,” Tintner said.

---------------