The Stunning Mach 6 SR-72 Darkstar Simply Summed Up in Just 1 Word

Key Points and Summary: Lockheed Martin’s SR-72 Darkstar, or “Son of Blackbird,” promises to redefine aerial warfare with a planned Mach 6 cruising speed, doubling the capabilities of its legendary predecessor, the SR-71.

-Designed with innovative turbine-based combined cycle (TBCC) engines, the SR-72 could evade air defenses by sheer velocity rather than relying solely on stealth.

-While defensive missile technology is advancing, potentially threatening hypersonic aircraft, the SR-72 could fill critical gaps left by the SR-71’s retirement, offering unprecedented reconnaissance flexibility.

-Although still conceptual, Lockheed Martin targets a 2030 deployment, aiming to restore America’s aerial advantage in contested environments. SR-72 Darkstar in 1 Word: Amazing (But Real?)

SR-72 Propulsion

SR-72’s propulsion is a significant innovation. However, little is definitively known about the jet; its power plants will likely be turbine-based combined cycle (TBCC) engines that integrate a conventional jet engine for subsonic and supersonic speeds with a scramjet for hypersonic flight, facilitating Mach 6 speeds.

Flight at hypersonic speeds offers significant strategic advantages. Traditionally, a jet’s stealth capabilities focused on radar cross-section evading radar detection.

Still, the SR-72’s speed allows it to outrun surface-to-air missile systems and minimize the time adversaries have to respond.

By flying at about two kilometers a second, the SR-72 could, in theory, fly into and out of airspace that slower, stealth-reliant aircraft would not be able to access.

If a “demonstrator aircraft can maintain level flight at Mach 6 using the new technology, a new international race could be triggered to develop hypersonic combat aircraft comparable to the fifth generation stealth fighter rivalry between the West, Russia, India and China,” a report by the Royal United Services Institute, a think tank explained.

Evolving Defenses

However, raw speed is no panacea. Though the SR-72 could outrun most, if not all, defensive missile systems today, that technology is rapidly improving, and the threat to hypersonic aircraft is growing.

“Certainly a Mach 6 cruise at operating altitudes of around 100,000ft would make SR-72 extremely challenging to intercept with traditional SAM systems. However, it is possible that progress in the anti-ballistic missile (ABM) field might challenge this theory,” the Royal United Services Institute said.

“The Raytheon Standard Missile 3 (SM-3) series recently demonstrated its capability to shoot down both low-orbit satellites and ballistic missiles.

Although the SM-3 is not designed for anti-aircraft work, its ability to intercept targets at extremely high altitudes and at closing speeds of over 22,000 mph could suggest that by the time SR-72 might enter service around 2030, SAMs could possess similar performance.”

Still, the SR-72’s capabilities could tackle some critical gaps for the United States military. With the retirement of the SR-71 reconnaissance aircraft in 1998, the United States lost the ability to rapidly surveil large swaths of the ground in a very short amount of time.

SR-72 Darkstar. Image Credit: Lockheed Matin with AI enhancement.

SR-72 Darkstar or SR-71 Son of Blackbird. Image Credit: Creative Commons.

SR-72 Darkstar. Image Credit: Lockheed Martin.

The SR-71 set several flight speed records that still stand today, including an absolute speed record of 2,193.167 mph and an absolute altitude record of 85,068.997 feet. Though the SR-71’s missile has largely been taken over by modern satellite technology, the satellite’s reliance on more rigid orbit patterns is not as flexible as a manned aircraft.

Although the SR-72 is very ambitious — and, for now, very much in the conceptual phase — Lockheed Martin has expressed confidence in the project’s feasibility. But if they can, it would be a remarkable feat of aeronautical engineering.

Previous reports suggested the SR-72 could enter service by 2030.

If Lockheed Martin can keep that timeline — and realize a hypersonic reconnaissance and strike aircraft — remains to be seen.

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.