A Look Back…Recoverable Rocket Boosters--A Future That Never Was Published April 9, 2021 By Tony R. Landis Air Force Materiel Command History Office The idea of making flight into space as routine as atmospheric flight has been around since the 1930’s when Eugen Sänger first published detailed information about his ideas for a suborbital, winged vehicle, capable of delivering a payload halfway around the world using a skip-glide technique that he referred to as “dynamic soaring.” Though Sänger’s ‘Silverbird’ would never be built, his concepts for winged flight into space became the subject of significant research well into the 21st century. As early as 1942, the United States became aware of Sänger’s work, when the (National Advisory Committee for Aeronautics (NACA) translated a copy of his 1934 study. Combined with the technological knowledge gained on rocket propulsion from the German scientists brought to the U.S. under Operation Paperclip during the final days of World War II, flight into space was beginning to become more of a reality than fantasy. Five months after studies presented at the First Symposium on Space Flight held in New York City in October 1951, Colliers Magazine published articles based on these studies titled “Man Will Conquer Space Soon.” Yet, it was the team of Walt Disney, Wernher von Braun and Willey Ley who first brought spaceflight to the American public with production of Man in Space, an hour-long television feature. An estimated 42 million viewers tuned in to watch the premier in October 1954. In the U.S., the Goodyear Aircraft Company produced some of the earliest conceptual work on winged flight into space. Their Manned Earth-satellite Terminal Evolving from earth-to-Orbit ferry Rocket (METEOR) de-sign research dates to early 1954. Over the next two decades, conceptual studies from nearly all major aerospace contractors, such as Bell Aircraft, Boeing, North American Aviation, Republic Aircraft, Convair and the Martin Company, became increasingly prevalent. Most projects funded by the Air Force under various Systems Requirements studies were given strange acronyms such as; BoMi, RoBo, HIRES, POBATO, ACES or simply referred to as Aerospaceplane. Many of the designs pushed the boundaries of reality and theory; proposing the use of materials that had yet to be invented, with propulsion systems that were purely theoretical at the time. On the drawing board were, liquid-fueled rocket engines, powered by; hydrogen and oxygen, and even nuclear-fuel. Single, dual and tri-cycle engines that combined the use of turbojet, ramjet and rocket propulsion into a single engine package, propelled these unique shapes into space. Vertical takeoff, horizontal takeoff including vertical and horizontal landing concepts were explored for their pros and cons; yet fully recoverable systems became the focus of many studies. Much of this research went into the design for the Space Transportation System, a compromised design using both reusable and expendable components. Though flown for 30 years, the shuttle never truly provided the economical or routine access to space that it originally envisioned. Significant effort was put into the National Aerospace Plane (NASP) project throughout the 1980’s and 90’s but was ultimately deemed uneconomical and too technologically advanced for production; the program terminated in 1993. Though not the advanced spaceplane engineers had originally envisioned, SpaceX achieved an economical, partially-reusable booster and capsule system in 2015 (the second stage booster is expendable). Single stage to orbit, fully-reusable winged vehicles, remain the Holy Grail of aerospace; but as technology advances, the visions of the past may yet become the vehicles of the future. Most of what you will find in this “Look Back” came from the archives of the Air Force Materiel Command History Office, a research facility located at Wright-Patterson AFB, Ohio. Research revealed a variety of gems, many a simple mention or illustration in an obscure report, while others came from archived materials supplied by the manufacturer or personal historical archives.