Son Of Blackbird: What Is The Lockheed Martin SR-72?

The Lockheed Martin SR-71 Blackbird is the fastest manned aircraft ever developed. It saw use during the Cold War and after, but since its retirement, nothing has matched its speed. The SR-72 is thought to be following it, with hypersonic speed, and may be in the air soon.

The Lockheed Martin SR-71 Blackbird

Before looking at the upcoming SR-72, we will take a look at its amazing predecessor. The SR-71 Blackbird was developed in the 1960s as a high-speed and long-range reconnaissance aircraft for use by the US Air Force (USAF). Lockheed Martin built 32 aircraft, which flew with the USAF (and NASA) between 1966 and 1999.

The SR-71 flew at speeds of just over Mach 3 and could operate at altitudes up to 85,000 feet. Its speed, altitude, and stealth design made it virtually unattackable.

Following it with the SR-72

The SR-71 was retired between 1998 and 1999, and nothing else has taken on the same role. It remains the fastest manned aircraft ever developed. A replacement has long been rumored - although nothing has ever been officially confirmed by the USAF.

Lockheed Martin (through its Advanced Development Programs, or 'Skunk Works') is believed to be developing the SR-72 aircraft, nicknamed so far as 'Son of Blackbird.' Lockheed Martin has openly discussed the design and concept of such an aircraft (but not for several years), although official details on its design, specifications, and roles are lacking. These rumors are summed up and discussed well by The Center for National Interest - and this information is used in this article. It is believed that the SR-72 will be a hypersonic, stealth aircraft used by the USAF (like the SR-71) for reconnaissance.

What is known about the SR-72

Officially, very little is known, and nothing has been confirmed. However, rumors and discussions suggest that the SR-72 will be quite a successor. It is thought to be an unmanned development, capable of hypersonic speeds of over Mach 5 (the SR-71 reached just over Mach 3, pictured below). This would give it the same ability as the SR-71 in earlier years - to outrun the latest missile defenses and remain unattackable.

Such hypersonic speeds will, of course, require major developments in the previous engine technology. The commonly discussed propulsion system for such an aircraft is a combination of a standard turbofan jet engine (for lower speeds) and a supersonic combustion ramjet or 'scramjet' for hypersonic speeds.

The challenge with current turbofan engines is the compressor. These have been used up to Mach 3, but over that, the moving parts hinder airflow and efficiency. A scramjet has no such moving parts and uses air pressure to create compression and propulsion.

Lockheed has tried scramjet development before. The Lockheed X-24C was a hypersonic research aircraft project in the 1970s, which aimed to reach speeds of Mach 6 to Mach 8. It was canceled, though, without any aircraft developed. Scarmjets were also 'used' with the Darkstar aircraft in the 2022 film Top Gun: Maverick.

When will we see the SR-72?

As regards the state of the program, again, nothing has been confirmed. The Center for National Interest, however, points to recent comments from Vago Muradian, the editor-in-chief of the Defense & Aerospace Report, that suggest the first prototype may have already been delivered to the USAF. There are suggestions, too, that it could fly in 2025. If this is the case, we will soon know what has been developed and how it performs.

The SR-72 is an exciting possibility, even though nothing is yet confirmed. Feel free to discuss the project and other aspects of hypersonic flight further in the comments section below.