The launch this week of Northrop Grumman’s current version of its Antares rocket from Virginia will be its last for a while, with its resupply missions to the International Space Station shifting to the Space Coast later this year.

The company’s Cygnus spacecraft on the NG-19 mission launched atop the rocket from NASA’s Wallops Flight Facility in Virginia’s Eastern Shore on Tuesday carrying more than 8,200 pounds of science experiments and supplies for an ISS rendezvous planned for early Friday. The spacecraft on this flight is dubbed the S.S Laurel Clark in deference to the NASA astronaut who was one of seven who died on board Space Shuttle Columbia on STS-107 in 2003 more than 20 years ago.

This marks the 20th time a Cygnus spacecraft has flown during a 10-year run all launching from Antares rockets from Virginia and carting up more than 130,000 pounds of supplies during its missions.

But this most recent launch marks the final supply of the Russian-made RD-181 engines used on the rocket’s first stage. A major portion of that stage is also fabricated by a Ukrainian company, so with both a federal law requiring companies to shift to U.S.-based engines in place for certain missions, and supply chain issues related to the war in Ukraine, Northrop Grumman announced in 2022 it would partner with Firefly Aerospace to create a new version of its Antares rocket.

The American-made redo, though, won’t be available until at least 2025, so Northrop Grumman made a deal with send its Cygnus spacecraft up on its next set of missions via SpaceX Falcon 9 rockets flying from Florida.

Its first flight, for NG-20, will be as early as December using SpaceX’s upgraded Space Launch Complex 40 that has been redeveloped in the last year at Cape Canaveral Space Force Station to be able to support crewed missions in addition to SpaceX’s existing capability from nearby Kennedy Space Center’s Launch Pad 39-A.

Northrop Grumman has at least two more resupply launches with SpaceX on tap in 2024, and potentially more through 2025.

Northrop Grumman is headquartered in West Falls Church, Virginia but has facilities all over the nation including several in Florida. Its acquisition of Orbital ATK in 2018 included NASA’s Commercial Resupply Services contract, the duties of which it shares with SpaceX so each company sends up their cargo spacecraft twice a year. The cadence means U.S.-based resupply arrivals for the astronauts on board about every three months. A third commercial cargo supplier in the form of Sierra Space’s Dream Chaser is looking to join them on regular resupply duties after it completes its test flights.

Unlike both SpaceX and Sierra Space’s options, the Cygnus spacecraft burns up on reentry into Earth’s atmosphere once done with its mission on the ISS. It does have the capacity to perform something useful for NASA, though, when attached to the station: the ability to fire up its engines and boost the station’s orbital altitude.

“It’s important that we continue to test that capability,” said NASA ISS Program Manager Joel Montalbano during a press conference last week. “As you know this will be about the third time we’ve done it with Cygnus, so we’re looking forward to continuing using that capability.”

Plans are to have it boost the ISS as much as 1.5 meters per second. The ISS relies on its Russian partners for reboost capability, so NASA is continuing to test out alternatives in the event that was no longer an option.

Northrop Grumman’s rocket engine issues, though, were the primary reason to hunt for an American-made solution, which allows for it to compete for Department of Defense missions. The Russian invasion of Ukraine, though, threw a curveball into the timeline.

Other U.S.-based launch providers have already been moving toward non-Russian rocket engines because of a congressional requirement restricting their use on Department of Defense missions after Dec. 31, 2022.

United Launch Alliance still uses Russian-made RD-180 engines on its Atlas V rockets, but will be switching to the BE-4 engines made by U.S. company Blue Origin for its new Vulcan rockets that could see its first launch before the end of the year. SpaceX’s Falcon 9 and Falcon Heavy rockets already use engines built by SpaceX in the U.S. as well. Other smaller rocket companies such as Rocket Lab, Relativity Space and Astra Space also have U.S.-made engines.

The new Antares 330 will use seven of Firefly’s Miranda engines and switch to Firefly for construction of the Antares first-stage tank. Northrop Grumman will continue to provide Antares avionics, software and the upper-stage rocket structure and engine.

The new rocket will allow for a larger launch capacity as well, the company stated. Its current launch capacity is just over 17,600 pounds to low-Earth orbit. In comparison, SpaceX’s Falcon 9 has just shy of a 21,000-pound payload capacity.