Decades before the space shuttle, U. S. Air Force officers and scientists were working on the Dyna-Soar, a single-pilot, reusable spaceplane that would have been boosted aloft by a Titan rocket. Before the heyday of unmanned aerial vehicles, an Air Force film spoke of the “emphasis on having a man on board” and of the new spaceplane requiring “the cool hand of a skilled pilot.” Before the digital age, the Dyna-Soar had a remarkably clean and functional cockpit, although it was cramped and festooned with toggle switches and round dials. Before heat-resistant ceramic tiles were used for shuttle re-entry, they were being studied for use on the Dyna-Soar.
“This was a ‘might have been’ that never displayed insurmountable flaws,” said Dr. Richard Hallion, former Air Force chief historian and an expert on hypersonics, in a telephone interview.
Dyna-Soar, a term apparently derived from “dynamic soaring” was the result of American plans in the early 1950s to develop a manned space bomber derived from work performed in Nazi Germany on the never-finished Saenger-Bredt Silbervogel (Silverbird) intercontinental skip-glide rocket bomber. The Silbervogel was intended to achieve long range by “skipping” off the atmosphere like a flat stone until it finally ran out of energy and had to land, presumably in Japanese territory. Dyna-Soar’s origins go back to Walter Dornberger, a leader of Germany’s V-2 rocket program and other projects at Peenemünde Army Research Center. Dornberger went to work at Bell Aircraft under chief engineer Robert J. Woods, who was on the National Advisory Committee for Aeronautics (NACA) committee for space flight and was a proponent of a manned hypersonic vehicle. His efforts were partly responsible for the North American X-15 rocket research aircraft.
The committee headed a study called Bomi (for “bomber and missile.”) Out of this study came a solicitation from the Air Research and Development Command (ARDC) in 1956 for Robo (“rocket bomber”), a boost-glide orbital strike system. The project was part of what NACA called Round Three, referring to an eventual follow-on to the X-15, which at that point had not yet flown.
To the Drawing Board
Following a Round Three conference on Oct. 18, 1957 – apparently scheduled before the world was stunned by the Soviet Union’s launch of the Sputnik satellite on Oct. 4 – ARDC issued plans for a delta wing, single-seat boost glider technology demonstrator. Dornberger designed a flat-bottom, low-wing craft intended to absorb the heat and
pressures of re-entry from space. In addition to Bell, ARDC looked at proposals from Boeing, Chance Vought, Convair, Douglas, General Electric, Lockheed, McDonnell, Martin, North American, Northrop, Republic and Western Electric – the roster a reminder of how many aerospace companies thrived in an earlier America. ARDC set up an Air Force project office at Wright-Patterson Air Force Base, Ohio.
It’s important to note that the X-20 designation associated with the Dyna-Soar – and which, in the context of the time, signified a peaceful research role – lay in the future. Officials were still hoping they would produce not merely an X-15 follow-on but a prototype for a space bomber able to deliver atomic weapons to the Soviet Union from low Earth orbit.
After two contractors were given the go-ahead to submit more detailed studies, on Nov. 9, 1959, ARDC selected Boeing to build the Dyna-Soar vehicle and Martin to built the booster, leaving Bell, which had done much of the pioneering work, with no part of the project.
At every stage of its design and development, Dyna-Soar was capable of being a fully orbital spacecraft, but as the program moved ahead, emphasis stayed on its capabilities as a suborbital, hypersonic spaceplane/glider that could “skip” along the earth’s atmosphere. Officials could claim, then, that it was not really a spacecraft.
The emphasis was partly due to rocket booster thrust limitations, even after the Titan III was developed to improve on the less powerful Titan I. But it was also meant to fit with President Dwight D. Eisenhower’s announced policy that the American human spaceflight effort should be directed by a civilian agency. The National Aeronautics and Space Administration (NASA) had replaced NACA on June 29, 1958, and was pressing ahead with the Mercury program, which would put an astronaut in space inside a capsule, disparagingly dubbed by test pilot Charles E. Yeager a “spam can.”
More Than a Capsule
Moving at a faster pace than they might today, designers fashioned a Dyna-Soar that eschewed the pointy appearance of a jet fighter and focused on a rounded shape designed to handle the shock waves associated with liftoff and landing. “It was a hot-temperature
structure using a nickel super alloy,” said Hallion. “The leading edges of the wing would be made of an even more exotic alloy. There was provision for active cooling.”
On separation from its booster, the Dyna-Soar would use A-4 or A-9 rocket engines to place the vehicle into an exoatmospheric trajectory from which it would eventually fall away. When it fell far enough, instead of re-entering it would use its wings and some of its speed to generate lift and would bounce (or “skip”) back into space. It would skip around the world until speed was reduced to the point where the pilot needed to select a landing site and return to the atmosphere.
Similarly to the future space shuttle, Dyna-Soar was designed to glide to earth like an airplane under the control of its pilot. It could land at an airfield, rather than simply falling to earth and landing with a parachute. Engineers decided not to use wheels, fearing the affect of heat on tires, so Dyna-Soar was configured with ski-like landing skids.
In 1960, seven astronauts were chosen in secret for the Dyna-Soar program, including Neil Armstrong, who moved to another project and was replaced by the time the names were released in 1962.
Belatedly giving the craft the designation X-20 on June 19, 1962, to imply a peaceful mission was not enough.
According to Hallion, when Dyna-Soar was cancelled on Sept. 10, 1963 after spacecraft construction had begun, the Air Force had spent $410 million in then-year dollars; Dyna-Soar was two one-half years and $373 million away from its first flight. “If we had pursued it as a black-world program like the U-2, it might have gone ahead,” said Hallion. “I never saw any technical issue that would have been a show stopper.”
Dyna-Soar leaves behind many achievements, including pushing the technology for high-temperature ground test facilities. It’s important to note that the program encountered no technological obstacles that engineers didn’t believe they could overcome.
Dyna-Soar is often compared to the space shuttle, which began flying on April 12, 1981 and completed its 135th and last orbital journey on July 21 of this year. The shuttle was too large and complex to offer cost-effective orbital capabilities for other than the costliest and most complex missions. But Dyna-Soar was also a progenitor and closer relative of the X-37B, the reusable robot spaceplane that was transferred from NASA to the Department of Defense in 2004.
Two X-37Bs have been boosted into low earth orbit from Vandenberg Air Force Base, Calif., by Atlas V 501 rockets, the second on May 5 of this year. The Air Force has said very little about the mission of the X-37B. Officials insist it is a research craft only and it is labeled a “test” vehicle, but space-watchers wonder if it has reconnaissance duties. Except for the absence of a human pilot on board, the X-37B could be a Dyna-Soar on steroids.
Some wonder if Dyna-Soar’s name might have contributed to its downfall. Hallion sad it would be difficult to testify on Capitol Hill and request money for something that sounded like a “dinosaur.” It could have succeeded, however, and it was clearly value for money.
“Just don’t call it ‘Jurassic Pork,'” said Hallion.