The USAF has released a teasing rendering of the Northrop Grumman B-21 Raider bomber.

The service recently revealed that the first two B-21s had been built at Plant 42 Palmdale near Los Angeles and were preparing for ground tests ahead of an anticipated first flight next year.

Following first flight, the test aircraft are expected to move to the 420th Flight Test Squadron at a dedicated Air Force Flight Test Centre facility – either at the nearby Edwards AFB or at Area 51 in Nevada – to continue development.

The rendering is light on details, but clearly shows a blended flying wing with obvious B-2 Spirit heritage, although the B-21 is believed to be quite a lot smaller than the B-2.

Despite the B-2 being the stealthiest of any known in-service aircraft, the 30 years since it entered service have seen advances in modelling and simulation, materials, shaping, manufacturing tolerances, and embedded sensors that are expected to realise a much smaller radar cross-section and electronic signature for the B-21.

Northrop Grumman is partnered on the program with Pratt & Whitney, BAE Systems, and Spirit Aerosystems. The USAF has a program of record for about 100 B-21s to replace the Rockwell B-1B and B-2, and an overall requirement for up to 175 aircraft. The first operational B-21 is scheduled for delivery to Ellsworth AFB in South Dakota in the mid-2020s.