The launch of the aircraft will be marked by a ceremony at the company’s production facility in Palmdale, California, US.
The company is currently working on a total of six B-21 test aircraft that are under different stages of final assembly at the Palmdale site.
Northrop Grumman Aeronautics Systems general manager and sector vice-president Doug Young said: “The B-21 is the most advanced military aircraft ever built and is a product of pioneering innovation and technological excellence.”
Following the official unveiling of the aircraft, the company will continue the test campaign under this B-21 programme to validate the aircraft’s performance and identify the necessary enhancements for the weapon system.
It will be carried out in collaboration with a combined team from the US Air Force Test Centre and Air Force Operational Test and Evaluation Centre.
The new B-21 long-range strike stealth bomber will gradually replace the USAF’s existing fleet of B-1 and B-2 bombers.
The initial contract for B-21 production was awarded to Northrop Grumman in 2015.
In May, the USAF and Northrop Grumman concluded B-21’s load calibration test and confirmed that the aircraft is expected to take its first flight next year.
However, the company said that the exact timings of the first flight will depend on the results of the aircraft’s ground test.
USAF chief of staff general CQ Brown Jr said: “We last introduced a new bomber over 30 years ago.
“The B-21 Raider will provide formidable combat capability across a range of operations in highly contested environments of the future.”