Engine issue on Northrop spacecraft delays NASA ISS cargo delivery

Washington: An uncrewed Northrop Grumman-built spacecraft in orbit experienced an issue with its main engine on Tuesday while attempting to reach the International Space Station to deliver scientific supplies, NASA said, delaying its arrival date as the agency devises a workaround.

Northrop's new Cygnus XL cargo craft launched aboard a SpaceX rocket from Florida on Sunday in a routine mission to deliver 11,000 pounds (4,990 kg) of cargo and research supplies to astronauts on the ISS, the football field-sized laboratory currently housing an international crew of seven.

In a statement late on Tuesday, NASA said Cygnus XL's main engine "stopped earlier than planned" early in the morning as it was executing two planned engine firings meant to raise its orbit closer to the ISS. All other systems on the craft are performing normally, NASA added.

The "XL" spacecraft is a much larger variant of Northrop's Cygnus cargo craft, which alongside SpaceX's Dragon craft has been one of NASA's main capsules that can ferry cargo to and from the ISS. The resupply mission is the first flight for the larger version.

NASA called off the craft's planned Wednesday arrival at the ISS as it works with Northrop to "evaluate an alternate burn plan for the resupply spacecraft." The agency did not disclose the spacecraft's altitude or detail any potential contingency plans.

"The Cygnus XL will not arrive to the space station on Wednesday, Sept. 17, as originally planned, with a new arrival date and time under review," the agency said.