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3D printed in white nylon plastic with a matte finish and slight grainy feel.
Although the North American X-15 is today famous for being the United States' most successful manned spaceplane, it was not the only craft developed for this purpose. In 1954, Douglas Aircraft proposed its own rocket-powered spaceplane, the D-558-3 "Skyflash," to compete with North American's design for the then-hostly contested NACA contract. The third design in Douglas' D-558 research plane series--the others being the D-558-1 "Skystreak" and the D-558-2 "Skyrocket"--the D-558-3 Skyflash was designed to be air-dropped by a Boeing B-52 and then use a Reaction Motors Model XLR-30-RM-2 Rocket unit to literally "go ballistic," climbing to 700,000 feet before finally leveling off and plunging back into the Earth's atmosphere at hypersonic speeds. Although Douglas engineers were making steady progress in solving the multiple challenges this concept posed, the U.S. Navy pulled its sponsorship of the D-558-3 Skyflash in 1955, and the project died while still in the wind tunnel testing stage.