Lockheed’s B-21 Raider, Skunk Works' Stealth Bomber Concept 'Senior Peg'

 

The rollout of the B-21 Raider, the most advanced officially disclosed aircraft mankind has ever built, has captured imaginations and has spurred new interest in the future of air combat in stealth bombers.

 At the same time, the B-2 Spirit, still alien looking many decades after first being shown to the public, is entering into the golden years of its service.  

 Northrop's original stealth flying wing represented an absolute quantum leap in military aviation technology and remains an icon of aerospace innovation. But there was another aircraft design that competed directly with it at the time four decades ago as part of the highly classified Advanced Technology Bomber (ATB) program. That was Lockheed Skunk Works' 'Senior Peg' stealth bomber concept.

 More than four decades after Northrop won the Advanced Technology Bomber competition, the available granular details about the competing design from Lockheed's famed Skunk Works advanced projects division, and its evolution, remain relatively limited. The War Zone has reached out in the past to Skunk Works for more information about the proposed aircraft and was told that there really wasn't anything in the company's archives to share that isn't out there already. As such, Senior Peg's story remains a relatively murky one with many gaps. What we do know is provided from unique on-the-record perspectives. 

 What is most immediately clear is that the relationship between the F-117A Nighthawk and its predecessors and the Senior Peg bomber concept is more than simply a product of Skunk Works having developed both of them. There is a direct lineage that can be traced from the Have Blue stealth demonstrator to Senior Peg.

 So, once again, in collaboration with master aerospace illustrator Adam Burch of Hangar-B Productions, and based on the information available, we created Senior Peg like you have never seen it before, bringing it to life as if it had won the stealth bomber race all those years ago and became an operational aircraft.

 There was comparatively little information to go of a single pole model photo in the public domain is the critical piece of information in this regard. Still, while many questions about the Skunk Works' stealth bomber that never was still remain, the pole model image provides a fantastic amount of details.

 The model image combined with on-the-record descriptions of the aircraft and its lineage, including knowing that Have Blue and the resulting Senior Trend design that turned into the F-117 had much influence on the Senior Peg configuration.

 The Skunk Works' goals for the aircraft, which focused on a smaller and more affordable design than Northrop's Senior Ice concept, likely featured a smaller set of arrays than those that ended up on the B-2. Northrop also learned a lot from their top-secret Tacit Blue demonstrator, which heavily influenced their Senior Ice design. That very stealthy aircraft carried a massive phased array radar with low-probability of intercept ground-moving target indicator capabilities that was a part of the larger Pave Mover program and offshoots of that radar capability ended up in the B-2.

 Finally, and clearly, the most bizarre part of the Senior Peg design was its little tail. This was clearly displayed on the pole model and was directly explained by Ben Rich in his incredible memoir Skunk Works.

 Defense Advanced Research Projects (DARPA) program called Experimental Survivable Tactical, or XST. DARPA's main objective with this effort was to acquire an advanced demonstrator aircraft designed to be very difficult to detect by radar, especially from the front and side, using passive, rather than active design features. Active measures in this context were things like electronic warfare jammers and other systems designed to actively interfere with an opponent's radars.

 Northrop and Lockheed. unusual faceted design ultimately won based heavily on the results of a so-called 'pole off' comparative test in which models of both designs were installed on a pole to measure their radar cross-sections (RCSs). which allowed for highly accurate radar cross-section (RCS) modeling on physical objects. 

 The Air Force subsequently requested options for transforming it into an operational combat aircraft. In 1977, the team at Skunk Works put forward two core proposals.

 The first of these was a fighter-sized type. The other was a larger 'small tactical bomber' more in line in terms of general role with the FB-111 Aardvark. These were referred to as the Advanced Tactical Aircraft-A and Advanced Tactical Aircraft -B, respectively.

 Fast forward and the B-2 Spirit would become the most expensive aircraft ever bought. This was due to a myriad of factors, Still, really, the B-2 was incredibly groundbreaking and with just 21 ever built, has always been somewhat experimental in nature.

 There is an interesting parallel here with the B-21 today, which, like Senior Peg, was designed from the outset to trade size and some complexity for lower cost and faster acquisition. We will never know what would have come of the ATB program if Senior Peg had won, but one has to wonder if Lockheed's approach would have resulted in a larger, more robust stealth bomber force and what exactly would have been traded in capabilities for it.

 Regardless, in the end, the Air Force got great value out of the small fleet of B-2s they ended up acquiring and that aircraft has given birth to the highly promising B-21 Raider.