Northrop Grumman’s Cygnus cargo craft with its two cymbal-shaped UltraFlex solar arrays deployed approaches the International Space Station on Aug. 6, 2024.
A SpaceX Falcon 9 rocket lifts off from Cape Canaveral Space Force Station, FL September 14, 2025 carrying cargo destined for the International Space Station. Craig Bailey, FLORIDA TODAY via USA TODAY NETWORK

A Northrop Grumman cargo spacecraft on a resupply run to the International Space Station has been waylaid in orbit due to mechanical troubles.

The uncrewed resupply mission, the 23rd commercial services mission that the Virginia aeronautics and defense company has undertaken on behalf of NASA, got off the ground Sunday, Sept. 14 from Cape Canaveral, Florida. The Northrop Grumman spacecraft, a Cygnus vehicle, was then due to dock Wednesday, Sept. 17 at the orbital outpost with a delivery of supplies and science experiments for the seven astronauts aboard.

NASA and Northrop Grumman, though, have delayed the spacecraft's arrival after an issue with its main engine was detected.

Flight engineers are now determining a new target arrival date for Cygnus, one of four vehicles contracted to transport cargo and other supplies to the orbital laboratory.

Here's what to know about the Northrop Grumman cargo resuppy mission and why it was delayed.

NASA, Northrop Grumman delay arrival of resupply vehicle to ISS

Northrop Grumman's Cygnus spacecraft, on a mission known as NG-23, managed to reach a safe altitude Sunday, Sept. 14 and deploy its two solar arrays needed to generate energy from the sun.

But the vehicle then encountered trouble when its main engine stopped earlier than it was supposed to amid two engine burns meant to raise the spacecraft's orbit as it approached the space station, according to NASA.

That means Cygnus will not arrive Sept. 17 at the ISS as intended. Instead, a new arrival date and time will soon be determined as flight controllers evaluate an alternate plan for the resupply spacecraft, NASA said in a blog post Sept. 16.

When did Northrop Grumman Cygnus XL launch from Florida on SpaceX Falcon 9?

The Nortrhop Grumman spacecraft launched at 6:11 p.m. on Sept. 14 on a SpaceX Falcon 9 rocket from the Cape Canaveral Space Force Station, located just south of NASA's Kennedy Space Center in Florida.

The company's latest version of its spacecraft, a larger iteration known as the Cygnus XL, is planning to deliver 11,000 pounds of scientific investigations and cargo to the orbiting laboratory for NASA. That includes dozens of research experiments that will be conducted during Expedition 73, according to NASA.

When Cygnus does arrive, NASA astronauts Jonny Kim and Zena Cardman have been tasked with capturing Cygnus using the station’s robotic arm. They will then install the spacecraft on the Earth-facing port of the station's Unity module, where the crew lives and works.

Russian Progress 93 reaches station days before Cygnus launch

The Cygnus XL would be the latest cargo spacecraft to reach the station in recent weeks.

The Progress 93 from Roscosmos, packed with three tons of food, fuel, and supplies, arrived at the orbital outpost Saturday, Sept. 13 when it docked to the Zvezda service module’s aft port. It will remain docked for about six months before it reenters Earth’s atmosphere to dispose of trash loaded by the crew. 

The vehicle had launched Sept. 11 on a Soyuz rocket from the Baikonur Cosmodrome, a spaceport Russia's space agency Roscosmos operates within Kazakhstan.

A SpaceX Dragon also recently reached the space station Aug. 25 with 5,000 pounds of supplies from Cape Canaveral on the CRS-33 mission.

Who is on the International Space Station?

Seven people are living aboard the International Space Station.

That includes four astroanuts who are part of a joint NASA and SpaceX mission known as Crew-11. NASA astronaut Zena Cardman; NASA astronaut Mike Fincke; Japanese astronaut Kimiya Yui of the Japan Aerospace Exploration Agency (JAXA); and Russian Oleg Platonov, a Roscosmos cosmonaut.

Crew-11 launched Aug. 1 from the Kennedy Space Center near Cape Canaveral, Florida. The spacefarers made their venture to space aboard a Dragon capsule that was propelled into orbit atop a SpaceX Falcon 9 rocket.

Also aboard the station is NASA astronaut Jonny Kim, who reached the ISS in April with cosmonauts Sergey Ryzhikov and Alexey Zubritsky.

This article originally appeared on USA TODAY: Engine troubles hamper Northrop Grumman resupply mission to International Space Station

Reporting by Eric Lagatta and Brooke Edwards, USA TODAY NETWORK / USA TODAY

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