SPACEPLANES OF THE 1950s AND 1960s

For many years official histories of the Soviet space program created the impression that Vostok had been the only Soviet piloted space project in the late 1950s/early 1960s. Not until the days of glasnost in the late 1980s/early 1990s did it emerge that just like the United States the Soviet Union had considered winged spacecraft as an alternative to ballistic capsules in the early years of the space program. Surprisingly, it turned out that this option was studied in no fewer than five design bureaus.

In the US winged spacecraft were long seen as the logical culmination of research into high-speed aeronautics conducted since the mid-1940s with air-launched rocket – propelled X-planes. The first phase had seen aircraft such as the X-1, X-2, and

Skyrocket gradually push the envelope from Mach 1 to Mach 3 between 1947 and 1956. Phase 2 had been initiated in late 1954 with the decision to press ahead with the development of the X-15 high-altitude hypersonic research aircraft, which eventually performed a largely successful test program between 1958 and 1969. Ultimately, suborbital and orbital capability would be achieved using the “boost-glide” principle, where a spaceplane would be launched vertically with the help of a con­ventional rocket and eventually glide back down to the runway like an ordinary aircraft. In late 1957, responding to Sputnik, the Air Force consolidated three “boost-glide” feasibility studies (Hywards, Brass Bell, and Rocket Bomber) into a single program called “Dyna-Soar” or X-20. Unlike the X-15, however, Dyna-Soar was not seen as an experimental system, but an operational weapon system capable of orbital nuclear bombardment, reconnaissance, and satellite identification and neutralization [13].

During 1958 the exigencies of the Cold War and the fledgling space race with the Soviet Union gradually pushed the ballistic capsule approach to the foreground, especially after the formation of NASA in October of that year. Having lost face after the early Sputnik successes, the United States was intent on restoring its reputation by putting the first man into orbit and capsules were a more efficient and quicker way of achieving that goal than winged spacecraft. The Air Force continued work on Dyna-Soar against the backdrop of NASA’s Project Mercury, but in December 1963, with the first flight an estimated three years away, Secretary of Defense Robert McNamara canceled the program. X-20 funds were reappropriated to a military space station called the Manned Orbiting Laboratory (MOL). After that the United States did not have another officially sanctioned spaceplane project until the approval of the Space Shuttle by President Nixon in early 1972.

The winged approach to piloted spaceflight was probably less central in Soviet thinking than it was in the US, at least when it came to building the first manned spacecraft. For one, the Soviet aviation industry and the Air Force were far removed from missiles and space-related matters after the Ministry of the Aviation Industry had declined offers in 1945-1946 to bear responsibility for long-range missile pro­grams. Instead, the assignment went to the Ministry of Armaments, which had developed artillery during the Second World War. This had far-reaching implications for the Soviet space program (essentially an offshoot of the missile program), which until the break-up of the USSR remained tightly in the grip of the “artillery” camp. Moreover, missiles were soon favored over strategic bombers to deliver nuclear warheads to US territory and there was little incentive for research into high-speed, high-altitude aircraft, reflected in the absence of high-altitude “X-type” airplane research programs in the Soviet Union. On top of that, Soviet leader Nikita Khrushchov had become particularly enamored with missiles in the mid-1950s, curtailing contracts for the aviation industry and even dissolving several aviation design bureaus towards the end of the decade.

The earliest plans for piloted missions beyond the atmosphere revolved around the use of converted R-2 missiles to send people on vertical trajectories to altitudes of up to 200 km. Although one common cabin design was planned, different methods were studied for returning the capsule to Earth. One option presented by Korolyov

during a speech in September 1955 was to equip such a capsule with wings, allowing it to make a long ballistic suborbital flight rather than a short vertical hop [14].

Research on piloted spaceflight began in earnest in the spring of 1957 with the establishment within OKB-1 of Department 9, which was to focus exclusively on the development of lunar probes and piloted spaceships, signaling the beginning of the bureau’s reorientation from missiles to spaceflight. Between September 1957 and January 1958 OKB-1 and the NII-1 research institute carried out a comparative analysis of various basic shapes for piloted spaceships, paying particular attention to thermal protection requirements and the ^-forces exerted on the crew. The con­clusion was that the heat-resistant alloys available at the time were not up to the task of protecting winged vehicles with high lift-to-drag ratios against the severe thermal stresses of re-entry. Instead, the recommendation was that the first piloted spaceship should have a lift-to-drag ratio between just 0.5 and 0, depending on the ^-forces that were deemed acceptable for the crew. The ship would preferably be shaped as a blunt cone with a rounded nose and a spherical base, with the pilot being ejected from the descent capsule before touchdown.

In April 1958 one of the main obstacles to manned ballistic flight was eliminated when a key meeting of leading experts in the field of aviation medicine came to the conclusion that people could withstand forces of up to 10g as long as the body was properly positioned inside the capsule. All this would lead later that year to preliminary designs for the manned vehicle that eventually became Vostok, redesigned in early 1959 to serve the dual function of carrying people into space and performing unmanned photoreconnaissance missions [15].