China reportedly has tested a combination glider and orbital vehicle that, fitted with a nuclear warhead, could strike the United States from the south, effectively evading many of the U.S. military’s early-warning radars.
The U.S. Air Force developed something similar six decades ago before the Pentagon canceled it on cost grounds. Incredibly, the American system itself copied an even older European concept.
Financial Times journalists Demetri Sevastopulo and Kathrin Hille first reported the August test of the potential fractional orbital bombardment system, or FOBS.
As its name implies, a glider-FOBS launches like a traditional intercontinental ballistic missile then enters a brief but stable orbit before de-orbiting after just a fraction of a trip around Earth—then gliding at hypersonic speed toward its target.
Where a traditional ICBM briefly escapes the atmosphere as it predictably arcs toward its target—over the North Pole, in the case of a Soviet or Chinese ICBM heading for the United States—a G-FOBS actually stays in orbit just long enough that, depending on its trajectory, it can attack from any of several directions.
As many of the most powerful strategic radars are fixed, and thus point in just one direction—north, usually—a FOBS or G-FOBS has great potential for an atomic sneak-attack. Especially if it can cross over the South Pole.
It’s a potentially destabilizing weapon but it’s hardly unprecedented. The Soviet Union between 1969 and ‘83 fielded a small number of these fractional, orbital missiles. But with an unguided reentry vehicle in place of the glider.
The Soviets cooled on FOBS in part owing to the weapon’s inaccuracy compared to conventional ICBMs. A pair of 1972 treaties with the United States—the Anti-Ballistic Missile treaty and the Strategic Arms Limitation Talks II—also helped kill off FOBS.
The United States years earlier almost deployed a similar system. But it was manned. The Dynamic Soaring space-plane, or “Dyna-Soar,” like the Chinese G-FOBS was a boost-glide system. The vehicle with its human pilot would boost into orbit atop a rocket then glide back to Earth.
A boost-glide space-plane could park in orbit for a hemispheric perspective on Earth and range far enough to drop atomic bombs anywhere on the planet on short notice — all while flying fast enough to dodge any conventional defense. It might even be reusable, a key quality for sustained wartime operations.
The Air Force formalized Dyna-Soar in 1957 and, in the six years before the Defense Department finally canceled the program, made a perhaps surprising amount of progress toward an actual, functional vehicle.
When a boost-glide space-plane belatedly reappeared in the United States a decade-and-a-half later, it was in the form of an arguably much-less-elegant NASA system. The bulky, fragile Space Shuttle—which wasn’t a weapon, of course.
A boost-glide space-plane might seem futuristic by 1950s standards, but in fact the basic idea pre-dated Dyna-Soar by many decades.
The first major boost-glide proposal came from the Austrian husband-wife team of Eugen Sänger and Irene Bredt. In 1933, Sänger and Bredt sketched a notional, rocket-propelled “antipodal bomber” that would launch horizontally from a sled, accelerate to 13 times the speed of sound while climbing through the Karman Line that separates Earth’s atmosphere from space.
Slowing and plunging back toward Earth, the 111-foot-long bomber would bounce off the upper atmosphere like a Mach-three stone skipping on water. It would drop its one-ton bomb on a target as far as 15,000 miles away then return for a gliding landing at the same base where it had launched.
Sänger and Bredt got as far as building a scale model for wind-tunnel tests before their sponsors in the Third Reich balked. The Nazis rarely met a high-concept weapons program they didn’t love, but the Sänger-Bredt antipodal bomber struck even them as far-fetched.
Two key figures were more impressed. One was Theodore von Karman, a Hungarian-born scientific advisor to U.S. Army Air Force general Hap Arnold. If von Karman’s name sounds familiar, it’s because he was the first to calculate the altitude where the atmosphere ends and space begins.
At the war’s end, von Karman led a team on a fact-finding tour of Europe on behalf of Arnold and the Army Air Force. Von Karman toured German aeronautical facilities, interviewed von Braun and von Braun’s mentor Walter Dornberger and gathered up documents.
He came across a study from Sänger and Bredt describing their antipodal bomber. Von Karman folded Sänger and Bredt’s work into his reports to the Army and, later, the Air Force. He apparently also had the Sänger-Bredt concept in mind when, in 1948, he helped to found the Research and Development Corporation think tank in California.
In May 1946, RAND handed over to the Army a key study on the future of U.S. military aeronautics. The study strongly endorsed military satellites as observation platforms and bombers—but didn’t specify exactly how those satellites should reach orbit.
Von Karman and RAND’s work laid the foundation for a boost-glide space-plane in the United States. Meanwhile, Soviet scientists were laying a similar foundation on the opposite side of the Iron Curtain. For the other party besides von Karman to take a strong interest in Sänger and Bredt’s work was Soviet premier Joseph Stalin.
The Soviet strongman was so enamored of the hypothetical space-plane that he dispatched a team to western Europe to locate Sänger and Bredt and either convince them to work for the Soviets—or kidnap them.
Stalin’s team failed. But the dictator’s interest in the boost-glide vehicle endured. He tasked Soviet scientists with developing a space-plane roughly matching the Sänger-Bredt antipodal bomber.
That work continued until 1953, when Sergei Korolev—a rocket-scientists Stalin had imprisoned then freed—completed work on the R-7, the USSR’s first ICBM and the basis of the space-launch-vehicle that eventually would deliver the Sputnik satellites into orbit.
Stalin was satisfied that he had a working launch vehicle and strategic weapon with global range. R-7 in hand, he didn’t need an antipodal bomber. Work on a boost-glide system called “Zvezda” effectively ended in the late 1950s.
The Americans stuck with it, though. Ironically, bureaucratic confusion and competition in the aftermath of NASA’s 1958 founding likely helped to sustain U.S. boost-glide efforts. As NASA absorbed more and more of the country’s space projects, the Air Force clung more tightly to whatever programs it still had in its column. That included the boost-glide vehicle.
While von Karman and RAND, borrowing heavily from Sänger and Bredt, helped to define what might be possible with a boost-glide space-plane, it was Dornberger who gave the concept shape.
After the British government finally released him from his post-war prison in 1947, Dornberger followed von Braun to the United States. He spent three years advising the Air Force on missile-guidance then, in 1950, took a plum job with Bell Aircraft Corporation. Bell’s most famous product was X-1, the first aircraft to fly faster than the speed of sound.
Dornberger provided to Bell a detailed concept for a boost-glide bomber. In 1952, Bell took its bomber-missile, or BOMI, to the Air Force.
BOMI was the antipodal bomber in everything but name. It would accelerate to a peak velocity of Mach 12 before settling into a Mach-four cruise over a range of up to 5,000 miles. Its payload would be a 7,000-pound nuclear bomb.
Air Force leaders were aware of Stalin’s interest in a boost-glide space-plane. They were keen to at least keep pace with the Soviets’ own efforts. The Air Force imagined it could develop and field BOMI by 1962. Incredibly, it got close.
RAND gazed into the proverbial crystal ball and concluded that rocket technology soon would advance to the point where nuclear-tipped ICBMs could take over from manned bombers as the United States’ main nuclear deterrent.
The think-tank worried that ICBMs would lack accuracy, reliability and yield. America would continue to require manned bombers for hunting down, and nuking, the most elusive Soviet forces.
But increasingly sophisticated air-defenses posed an existential threat to the traditional, air-breathing manned bomber. A space-plane however could fly over—and outrun—any conceivable surface-to-air missile.
In addition to flying high and fast, an antipodal bomber was maneuverable. And that made it unpredictable. That unpredictability gave the boost-glide vehicle enduring value, even as ICBMs proliferated.
Early ICBMs lacked true global range. To reach the Soviet Union from the United States or vice versa, they traveled over the North Pole. This made them predictable. Even early submarine-launched ballistic nukes were fairly easy to anticipate, as the subs needed to close within a thousand or miles or so of their targets. This narrowed their options.
The first-generation early-warning systems that the United States and Soviet Union developed in the early 1960s had gaps. The American system didn’t have much in the way of south-gazing sensors. The Soviet system mostly looked north and, to a lesser extent, south. It was blind to the east and west.
An antipodal bomber could exploit these gaps.
The Air Force didn’t just hand the space-plane contract to Bell. The service had options. No fewer than four separate boost-glide program offices and a dozen aerospace firms were working in parallel on boost-glide designs.
Finally in 1957, the Air Force collapsed all the competing efforts into one program, Dyna-Soar. The goal was, by 1974, to produce a boost-glide vehicle with a maximum speed of Mach 20, a ceiling of 300,000 feet and a range of 10,000 miles.
Rather than skipping off the atmosphere, per Sänger and Bredt’s proposal, Dyna-Soar would boost through the Karman Line … then glide back down in a simple, fiery arc.
The bomber-missile would be capable of several missions—nuclear bombardment, reconnaissance and “satellite-inspection.” The latter was something of a misnomer. Not only should Dyna-Soar be able to survey an enemy satellite—it should be able to dismantle it, as well.
The competition to develop the Dyna-Soar came down to two companies. Bell, of course—which owing in part to Dornberger’s expertise already had a pretty good idea what an operational space-plane should look like. The New York firm started pitching space-plane concepts to the Air Force as early as 1952.
Then there was Boeing. The Chicago plane-maker came late to Dyna-Soar, but the design it proposed for the Dyna-Soar program had the advantage of being lighter than its rivals were. That in turn meant less demand on the rocket that would accelerate the space-plane to hypersonic speed.
In June 1959, the Air Force tapped Boeing to build Dyna-Soar. Considering how advanced Bell’s space-plane design was compared to its competitors’ own designs, it was a controversial decision. Indeed, as Boeing’s blueprints for the operational Dyna-Soar evolved between 1959 and the design freeze in early 1960, they started looking more and more like … Bell’s own blueprints.
In February 1962, U.S. defense secretary Robert McNamara endorsed a plan to launch the first manned Dyna-Soar flight in late 1965 at a cost of $700 million—that’s $6 billion in 2021.
He also wanted the Air Force to work on an orbital station. In August that year, the Air Force cut a contract with Douglas Aircraft Company and General Electric to begin outlining a concept for a so-called “Manned Orbital Laboratory.”
The plan was for these two efforts eventually to merge. An evolved version of the Dyna-Soar with a passenger compartment for four people would fly back-and-forth resupply missions for the MOL space station in low orbit.
At some point in the early 1960s, the idea that Dyna-Soar would function as an atomic bomber sort of … faded away. ICBMs by the year were getting more powerful and accurate. American and Soviet leadership were beginning to grasp the concept of mutual deterrence, which requires both countries to be vulnerable to each other’s nuclear arsenals.
Dyna-Soar was becoming an expensive, redundant distraction. By June 1963, McNamara had made up his mind. The Air Force didn’t need Dyna-Soar. Not when it had ICBMs for deterrence and, to support its MOL station, could copy NASA’s Gemini spacecraft, paint it blue and send it on military missions.
McNamara canceled Dyna-Soar in December ‘63. America’s piloted G-FOBS went into hibernation until NASA revived the underlying concept, minus the bomb, in the form of the Space Shuttle. The Soviets soon deployed their own FOBS for a few years before it, too, faded away.
Four decades later, China might be taking its own swing at the idea of a fractional, orbital nuke. It’s alarming. But it’s not new.