The Soviet Union Designed Its Very Own Version of the SR-71 Blackbird

September 10, 2021 Topic: SR-71 Region: Eurasia Blog Brand: The Reboot Tags: Cold WarSR-71 BlackbirdU.S. Air ForceSoviet UnionLong-Range Fighter

The Soviet Union Designed Its Very Own Version of the SR-71 Blackbird

The Soviet version actually predated the A-12 and SR-71 by several years.

 

Here's What You Need to Know: Soviet engineer Pavel Tsybin first proposed the project in 1954.

It’s a cliché of the Cold War that no sooner did one superpower pioneer a new weapons technology that its rival swiftly sought its own copy, canceling out any advantage long-term. Though this frequently did occur, the Soviet Union and the West had diverging theories about precisely which platforms would most reinforce their security posture.

 

For example, during the 1950s and 60s, the United States invested considerably in various spy planes designed to penetrate hostile airspace such as the high-flying RB-57 and U-2, followed by the Mach 3-cruising A-12 and SR-71 Blackbirds.

However, the Soviet Union was never convinced such technically impressive penetrating strategic reconnaissance planes were a great idea. They ultimately struggled to keep up with advances in surface-to-air missile technology, and potential shoot-downs could result in embarrassing diplomatic incidents. Better to use deniable agents on the ground or orbiting satellites without risk of embarrassing Soviet leaders.

Still, brilliant Soviet engineer Pavel Tsybin came close to developing a “Soviet Blackbird”—though it, in fact, predated the A-12/Blackbird by several years and was originally conceived as a nuclear bomber.

Compared to famous Soviet bureaus such as Mikoyan i Gurevich (MiG), Sukhoi and Tupolev, the design bureau OKB-256 headed by Tsybin remained small and had to fight for its small chunk of the Soviet defense budget. But the aeronautical engineer was thinking big when he proposed in 1954 to develop the Reaktivny Samolet (RS) ramjet-powered bomber that could cruise at three times the speed of sound.

Tsybin was aiming sky-high with his planned performance parameters: a maximum range of 10,000 miles, a service ceiling of 98,000 feet, and a cruising speed of two-and-half times the speed of sound. With that performance, the RS could have delivered intercontinental nuclear strikes at speeds and altitudes that would have rendered interception nearly impossible. The RS would have ramjets incorporated into two pods on tips of very small and thin wings. Canards (additional small wings on the nose of the plane) provided additional lift.

Ramjets perform superbly at high speeds by sucking incoming air—but don’t function well at all at low speeds.

The enterprising engineer’s presentation blew away the Soviet defense ministry, and his small team was asked to develop a flying prototype by 1957. But as Tysbin advanced into development, he was forced to reduce the RS’s planned range to only 4,500 miles. That simply wasn’t far enough for a round-trip intercontinental bombing raid.

Tsybin then turned to a concept developed by the Soviet Union in the 1930-40s—carrying shorter-range aircraft on large motherships. These flying aircraft carriers had even been briefly but successfully combat-tested in World War II.

Thus, the revised RS concept was to be carried inside a specially modified Tu-95-N long-range bomber, which would release the RS at 30,000 feet. Two jettisonable rocket engines would help accelerate the parasite-bomber to Mach 2.4 to 20.8, at which speed its ramjet engines could then operate efficiently and sustainably. The RS could then deliver a 2,425-pound nuclear glide bomb.

 

However, following the Soviet Union’s first successful test of an intercontinental ballistic missile, the defense ministry lost interest in deep-penetrating strategic jet bombers and canceled the RS project. Thereafter, Soviet supersonic bombers like the Tu-22 were focused on using standoff range weapons and anti-ship missions.

Undeterred, Tsybin then proposed the RS could be reconfigured into a strategic spy plane called the 2RS. This ditched the canards and nuclear bomb armament for cameras, but retained the airborne launch scheme. This project too proved short-lived.

The final iteration of Tsybin’s concept was the RSR, which was more conventional in that it was to be powered by two Soloviev D-21 turbofan engines with ramjet-like characteristics, and was designed for ground takeoff and landing using two twin-wheel landing gears under the tail and nose. To compensate for lost power, the airframe was built out of lightweight duraluminum.

The pilot sat in a pressurized cabin and used fully-powered controls, while the exterior skin was made to tolerate temperatures as of up to 220 degrees centigrade generated by the friction of passing air molecules.

By then the U.S. deployment of the world’s first operational surface-to-air missiles—the Nike Ajax—factored into the RSR’s design. It was to be coated with a porous radar-absorbent material (RAM) designed to reduce its radar-cross-section—one of the first planned applications of RAM, which has evolved into a critical air warfare technology today. Tsybin also intended to build in high-stress tolerances so the RSR could perform barrel rolls and other high-G maneuvers to evade incoming SAMs.

However, the RSR’s combat radius was now down to just over 2,300 miles. To add versatility, Tsybin proposed the RSR could be dually capable as a spy plane or a bomber which either perform ground-based takeoffs or air-launch from a Tu-95N bomber. Unfortunately for Tysbin, aviation designer Andrei Tupolev thought developing the Tu-95N to be a waste of time and pawned it off to the Myasishchev design bureau. Furthermore, he monopolized production of the D-21 engines for his own aircraft, denying them to the RSR project.

By 1957, OKB-256 had built an NM-1 three-quarter-scale demonstrator equipped with two Mikulin AM-5 turbojets instead. After multiple delays, the subsonic test model made the first of 32 test flights on April 7, 1959. These revealed the airframe’s unstable takeoff handling and flight characteristics—meaning the jet needed to be re-engineered.

Tysbin swapped out the never-delivered D-21 engines for Tumansky R-11F turbojet used on the MiG-21 and Su-15, and trimmed away weight by shortening tail fins, thinning out wing surfaces and replacing rivets with welding. The resulting aircraft, with trapezoidal wings truncated by turbojet engines, looked like a weird cross between the SR-71 and F-104—or an awesome sci-fi spaceship.

You can see more detailed specifications for the RSR-020 here, and schematics for the various RS models here.

Five revised RSR R-020 were ordered—but then in October 1959, the short-lived OKB-256 bureau was absorbed by Myasishchev—best known for its wide-winged M-4 “Hammer” strategic bomber. This was done at Khrushchev’s direction, who preferred to invest in ICBMs rather than bombers.

Supposedly, three or five RSR-020s airframes were completed at the No.99 factory at Ulan-Ude, Siberia, awaiting only fitting of their engines. However, the project was axed on October 1960 and the airframes eventually scrapped, over the objections of the disappointed engineers. Tysbin would go on to play a major role in the development of Soviet spacecraft including the Soyuz-1 and -2 and the Buran space shuttle.

The otherworldly looking RSR was killed as much by its bureaucratic enemies as the technological challenges of its development—but it’s interesting to speculate what response it might have elicited from the United States had it ever been deployed.

Sébastien Roblin holds a Master’s Degree in Conflict Resolution from Georgetown University and served as a university instructor for the Peace Corps in China. He has also worked in education, editing, and refugee resettlement in France and the United States.

This article first appeared in June 2019.

Image: NASA / Wikimedia Commons