The B-1 bomber shows up on radar as a 10-square-meter target — roughly the size of a car. The B-2 Spirit reduced that to the size of a bumblebee, and the new photos of the B-21 Raider confirm its radar signature is even smaller — approximately the size of a mosquito, virtually invisible to the radar systems designed to find it.
What Do The Recent B-21 Raider Photos Tell Us?
The Northrop Grumman B-21 Raider, a sixth-generation stealth bomber, will be one of the stealthiest aircraft in U.S. history.
Although it outwardly resembles the B-2 Spirit, it is a smaller aircraft with a wingspan estimated at 132-150 feet. compared with the B-2’s 172 ft., and is approximately half the empty weight.
Developed under the Long Range Strike Bomber (LRS-B) program, it is intended to replace the B-2 Spirit, and eventually join with the B-52H as part of a modern, long-range bomber force.
B-21 Raider. Image Credit: USAF.
B-21 Raider Taking on Fuel. Image Credit: U.S. Air Force.
Recent Photos During Aerial Refueling Are Quite Revealing:
Recent B-21 Raider photos, released this week during an aerial refueling operation, confirm that it is a compact, highly advanced flying-wing aircraft with deeply blended engine intakes, small cockpit windows for enhanced stealth, and a unique two-piece clamshell dorsal refueling door.
The imagery indicates a mature, operational-ready design that focuses on reducing infrared signatures through hidden exhausts.
It appears the aircraft is close to entering operational service.
“Our teams are moving the B-21 Raider through testing at an unprecedented pace, continually proving its outstanding performance – including aerial refueling,” said Tom Jones, corporate vice president and president, Northrop Grumman Aeronautics Systems.
A covered Northrop Grumman B-21 Raider is displayed during a practice unveiling ceremony at Northrop Grumman’s manufacturing facility on Air Force Plant 42 in Palmdale, California, Dec. 1, 2022. The B-21 will be a long-range, highly survivable, penetrating strike stealth bomber capable of delivering both conventional and nuclear munitions. (U.S. Air Force photo by Airman 1st Class Joshua M. Carroll)
“We’ve designed and built a reliable, adaptable aircraft that is vital to our warfighters’ missions, while operating with a sense of wartime urgency to accelerate production and deliver this capability.”
“Most Fuel-Efficient Bomber Ever Built”:
“As the most fuel-efficient bomber ever built, the B-21 consumes a fraction of the fuel used by fourth- and fifth-generation aircraft. This reduces demand for theatre tanker logistics and provides operational commanders with greater flexibility in force packaging,” Northrop Grumman said in its press release.
“With more than $5 billion invested in digital technologies and manufacturing infrastructure for the B-21 program, Northrop Grumman is accelerating its production, with the first aircraft planned to arrive at Ellsworth Air Force Base in 2027.“
With two engines, rather than four, a smaller payload, and an increased amount of fuel, the aircraft was designed to have a longer range with less aerial refueling reliance.
“This capability ensures we can deliver penetrating long-range strike anywhere in the world, at any time,” Air Force Global Strike Command boss Gen. S.L. Davis said in an announcement. “For our bomber crews and the combatant commanders they support, this is about endurance and mission readiness.”
Engine Inlets And Exhausts Are Seen Clearly:
The overhead photo was particularly significant because it exposed parts of the aircraft that are typically among the most closely guarded in stealth design: the engine inlets and exhaust configuration.
The inlets are deeply recessed, and the exhausts are much more rounded than the B-2.
The B-21 has deeply blended air intakes and, as TWZ noted, is the “deeply-sunk chevron-shaped (inverse direction compared to B-2) low-observable exhausts placed very far forward of the aircraft’s trailing edge to help mask its infrared signature. But what’s missing is any kind of special material that would attenuate the heat generated from the hot gases and protect the airframe from it.”
B-21 Raider. Image Credit: U.S. Air Force.
That itself raises the question of how thermal management, i.e., heat dissipation, is achieved. TWZ theorized that the image could have been altered to protect that technology.
The cockpit windows are also much smaller than the B-2’s, which is a tradeoff between the pilot’s visibility during aerial refueling operations and minimizing its radar cross section.
The “Skunk Works” Said The Smaller Size Was Part of the Plan:
The B-21’s smaller size is a deliberate design choice, said Lockheed Martin’s famous “Skunk Works” experimental division. According to the engineers, the smaller size enhances the plane’s strategic and operational advantages.
Bigger isn’t always better (in stealth aircraft). As sensors, signal processing methods, and the integration of multi-band systems have evolved, modern systems are much better at detecting even stealth aircraft.
Stealth aircraft minimize their radar cross section through angular shapes that deflect waves, absorbent materials (RAM), and extreme attention to reflective parts (leading edges, fins, air intakes). Low-frequency radars are better at detecting stealth aircraft.
The smaller the aircraft, the smaller the radar cross-section and radar return. The radar cross section (RCS) of the B-1 bomber is 10m2. The B-2 bomber has an RCS of 0.0001m2, the same as the F-22, the size of a bumblebee. The B-21 bomber is virtually invisible to UHF/VHF radar. It’s about the size of a mosquito.
Sixth-Generation Stealth Characteristics Play A Huge Part in the B-21:
The B-21 Raider has a 132-150-foot wingspan in contrast to the B-2’s 172-foot wingspan; however, the primary differences between the aircraft are not measured by size, but the technology.
The B-2 features Gen-1 stealth technology, developed in the 1980s and 90s. This technology is still effective—as seen during the B-2’s June airstrikes, inside Iranian airspace. The B-21, however, features far more advanced 6th-Generation technology, the type that is on the cutting edge today.
The computerized AI-assisted design of the B-21 was configured to calculate the placement of every surface, bolt, and seam to reduce signature across RF, IR, and acoustic spectrums.
The result is an aircraft that has 360-degree low observability. In contrast, the B-2 was built with stealth optimization merely from the front, whereas it was much more detectable from the rear.
B-21 Raider Stealth Bomber. Image Credit: Industry Handout.
An artist illustration depicts a U.S. Air Force extended-range B-21 Raider escorted on a mission by armed unmanned next generation air dominance platforms. This fictional bomber features longer, wider wings, and a deeper fuselage that accommodates larger fuel tanks and dual weapons bays that enables the bomber to carry a much larger and varied payload. Mike Tsukamoto/staff; Greg Davis/USAF
Modernized processes will also make the B-21 easier and less costly to maintain than prior systems, ensuring the fleet’s operational readiness for our nation’s most critical missions.
Smaller, More Flexible, Survivable:
The B-21’s compact design will enable it to penetrate China’s area-denial strategy, known as Anti-Access/Area Denial (A2/AD), more effectively, ensuring it can deliver precision strikes or gather intelligence in high-threat environments where the larger B-2 might face greater risks.
The B-21’s smaller size also translates into greater operational flexibility. The B-2 Spirit, with its massive wingspan and heavy payload capacity, was designed for long-range, high-payload missions, often carrying large nuclear or conventional munitions over intercontinental distances.
The B-21’s open-system architecture will enable frequent updates to its onboard systems, not only affecting the types of weapons it can carry but also making it easier to upgrade the bomber’s avionics.
It has been reported that the B-21 can take off and land from smaller, more austere airfields. The aircraft will not require climate-controlled hangars like the B-2s.
The B-21 Raider Prioritizes Precision Over Payload:
Advancements in weapons and targeting systems have changed the Air Force’s doctrine. The massive Arc Light bombing of B-52s over Vietnam isn’t needed as much any longer. Instead, the B-21 will focus on delivering precision weapons.
The B-2 Spirit had a weapons payload of 40,000 pounds. The B-21’s payload will be smaller, possibly only 30,000 pounds, but enough capacity to carry the 30,000-pound GBU-57 Massive Ordnance Penetrator (MOP). But with more weapon precision, the effectiveness of the Raider will increase.
The smaller B-21 will have greater flexibility and play a key role in multi-domain operations, integrating with space, cyber, and ground-based assets to provide a comprehensive and coordinated response to threats, including the CCA “loyal wingman” program.
B-21 Program Has Accelerated Production:
The Air Force announced a $4.5 billion deal with Northrop Grumman in late February to accelerate production of B-21 bombers by 25 percent. Congress approved the additional funding for the deal as part of its reconciliation package—officially called the One Big Beautiful Bill Act—last summer.
While the photos do not paint a complete picture of the aircraft, they do show its improvements in stealth, endurance, and efficiency. Best of all, the program is scheduled for on-time, on-budget delivery.
About the Author: Steve Balestrieri
Steve Balestrieri is a National Security Columnist. He served as a US Army Special Forces NCO and Warrant Officer. In addition to writing on defense, he covers the NFL for PatsFans.com and is a member of the Pro Football Writers of America (PFWA). His work was regularly featured in many military publications.
