On February 26th, 2016, the designation of "B-21" was revealed for the upcoming Northrop Grumman LRS-B program. Artist renderings were also revealed and showcase a bomber form not unlike the current B-2A "Spirit" series currently in USAF service. Performance and capabilities will be forthcoming as the project is evolved - as such, this article will be updated accordingly.
Partners announced for the B-21 program are Pratt & Whitney (engines), BAe Systems (electronics), GKN Aerospace (metals and composites), Janicki Industries (composites and tooling), Orbital ATK (wing skins and nacelles), Spirit Aerosystems (metals and composites), and Rockwell Collins (communications). Northrop Grumman will provide the onboard radar fit.
The B-21 is expected to enter service in the latter half of the 2020s with a target fleet of 100 aircraft. These will be used to succeed (perhaps optimistically at this point) the aging line of Boeing B-52, Rockwell B-1 and even Northrop's own B-2 stealth bombers currently in service. The USAF's Rapid Capabilities Office (RCO) is heading the initiative.
Based on released artist renderings, the B-21 will have an all-wing planform not unlike the B-2A "Spirit" stealth bomber, incorporating all learned, and possibly new, stealth techniques into its design. The flight crew numbers two and the team is seated at the apex of the "arrow" shape of the planform. All major compartments are situated at the center mass of the aircraft whose fuselage is blended into the wings to promote a very-low-profile when viewed from the size. At rear, the engines will be (as in the B-2A) embedded into the design with its exhaust protected as much as possible from IR locators. A conventional, multi-wheeled retractable tricycle undercarriage is assumed for ground-running. An unmanned option has been bandied about for the new bomber design.
Compared to the B-2A, the B-21 will be given an extended nose section, or "beak", forming the apex of the arrow-like form. The nose leg of the undercarriage is set to be placed further aft in the nose compartment and will be made to a shorter height specification while the main legs are simplified by showcasing fewer wheel bogies. The cockpit is detailed with two windscreens (as opposed to four as seen in the B-2A) and the engine inlet will be integrated closer to the center mass of the fuselage, reducing the overall length of the fuselage itself. Attention is being paid to medium-/higher-altitude flight controlling by implementation of a simplified wing by the trailing edges and "sawtooth" leading edges.
Overall dimensions appear to indicate a smaller overall bomber form when compared to the relatively massive B-2A though true specifications have yet to be revealed.