Article Summary: DARPA is developing a stealthy, hypersonic strike aircraft, known as the Next Generation Responsive Strike (NextRS) platform.
Key Point #1 – Designed to operate in highly contested environments, the NextRS aims to combine Mach 5+ speeds with low observability, overcoming extreme engineering challenges. The project focuses on high-temperature materials, advanced propulsion systems, thermal management, and hypersonic weapon deployment.
Key Point #2 – DARPA, working with the Air Force Research Laboratory (AFRL) and NASA, hopes to field a prototype by the end of the decade. If successful, NextRS could revolutionize strike missions, offering unprecedented speed, range, and survivability in modern warfare.
DARPA Wants to Build a Stealthy, Hypersonic Strike Aircraft
One of DARPA’s least-known departments is soliciting proposals for a radically new type of platform: a hypersonic strike aircraft that is also very stealthy. The office, the Aerospace Projects Office, is not listed as one of the secretive organization’s six technical offices, nor is it among DARPA’s nine support offices.
But, according to their call for proposals, they’ve got an ambitious project in mind.
“The Aerospace Projects Office (APO), working in close partnership with Air Force Research Laboratory (AFRL) and the National Aeronautics and Space Administration (NASA), develops and demonstrates technologies which enable Next Generation Responsive Strike (Next RS) air platforms,” their announcement said.
“APO envisions reusable hypersonic aircraft attributes providing future multi-mission strike/ISR capabilities against targets protected by advanced air defense systems. APO is seeking innovative technologies that close the gap between the state-of-the-art in reusable hypersonics and the level of technical maturity required to initiate a NextRS Y-Plane design and development program later this decade.”
Engineering Challenges Galore
But it won’t be easy — DARPA exists to rapidly develop technologies that are not yet mature but that they would like to see within the medium term. The technical and engineering challenges to building a viable hypersonic aircraft that is also stealthy are immense.
DARPA’s call for proposals acknowledges as much. “APO recognizes that a full suite of aircraft and mission systems technologies are needed to eventually field a NextRS weapon system. APO’s focus is strictly on aircraft technology development and demonstrations that reduce risk in specific technical areas to enable future design of reusable hypersonic aircraft.”
“These aircraft technologies will be compatible with the hypersonic environment, modern avionics power/thermal needs and aircraft-like life cycles and time scales.”
What DARPA Wants in a Hypersonic Bomber
The announcement goes on to list six areas of interest for the Aerospace Projects Office and expands a bit on what they hope those six areas will achieve.
-Structures and Materials – technologies for high temperature metallic materials and structural concepts that allow design of thermally driven, weight-efficient airframes.
-High Speed Weapon Separation – technologies that allow weapons, weapon bays and ejection systems to accommodate hypersonic separation from aircraft and flyout to the target.
-Dual mode propulsion – technologies that allow continuous powered operation of a Turbine Based Combined Cycle (TBCC) propulsion system over the entire flight envelope.
-Power Generation – technologies that allow power generation sufficient to support a modern avionics and sensor suite during all periods of flight.
-Thermal Management Systems – technologies that allow integrated solutions to managing the thermal environment of the aircraft and propulsion system.
-High Mach Turbine Engine – technologies that allow efficient TBCC operations through ascending and descending mode transition without the need for water injection.
The Challenge Will Be Historic
DARPA’s proposal explains that it hopes to ultimately yield an aircraft with a Y-plane designation, indicating a prototype aircraft rather than a purely experimental aircraft like the X-planes of Cold War fame. However, the challenges will be immense.
At high Mach speeds, managing the immense amount of heat generated by atmosphere friction over an airframe is one problem, but for an aircraft that could survive in a highly contested environment, like a stealth aircraft, presents an even more significant challenge, though it has been done before.
The SR-71 Blackbird, the strategic reconnaissance aircraft developed by Lockheed to spy on the Soviet Union during the Cold War, achieved speeds in excess of Mach 3 and possessed some stealth characteristics thanks to its steep chine that ran along its nose and fuselage. However, that aircraft did not have any weaponry.
SR-71. SR-71 photo taken at the National Air and Space Museum. Taken by 19FortyFive on 10/1/2022.
Weapons are typically ferried internally in stealth aircraft to preserve their reduced radar cross-section. But opening a weapons bay at high Mach speeds is no easy feat, as the bay doors need to withstand the incredible amount of stress placed on them.
Still, DARPA indicated that they’d like to have a prototype later this decade. There are still five years left to answer the Next Generation Responsive Strike platform’s engineering challenges.
SR-71. SR-71 photo taken at the National Air and Space Museum. Taken by 19FortyFive on 10/1/2022.
About the Author: Caleb Larson
Caleb Larson is an American multiformat journalist based in Berlin, Germany. His work covers the intersection of conflict and society, focusing on American foreign policy and European security. He has reported from Germany, Russia, and the United States. Most recently, he covered the war in Ukraine, reporting extensively on the war’s shifting battle lines from Donbas and writing on the war’s civilian and humanitarian toll. Previously, he worked as a Defense Reporter for POLITICO Europe. You can follow his latest work on X.
