Viking (rocket)

After World War II, the United States Army experimented with captured German V-2 rockets as part of the Hermes program. The number of V-2s available for all research was limited and Hermes was an Army project. The US Navy had the need to develop advanced missiles for both weapons and research purposes. The US Navy issued a contract 21 August 1946 to the Glenn L. Martin Company for a series of 10 large liquid-fueled rockets. The intent was to provide an independent US capability in rocketry, and to provide a vehicle better suited to scientific research. Originally dubbed "Neptune," it was renamed "Viking" in 1947 to avoid confusion with the Lockheed P-2 Neptune. The Viking was the most advanced large, liquid-fueled rocket being developed in the US at the time. == Design ==

The Viking was roughly half the size, in terms of mass and power, of the V-2. Both were actively guided rockets, fueled with the same propellant (Ethyl alcohol and liquid oxygen), which were fed to a single large pump-fed engine by two turbine-driven pumps. The Reaction Motors XLR10-RM-2 engine was the largest liquid-fueled rocket engine developed in the United States up to that time, producing of thrust at sea level, and in a vacuum. The specific impulse was and respectively, with a mission time of 103 seconds. As was also the case for the V-2, hydrogen peroxide was converted to steam to drive the turbopump that fed fuel and oxidizer into the engine. XLR-10-RM-2 was regeneratively cooled. Viking pioneered important innovations over the V-2. One of the most significant for rocketry was the use of a gimbaled thrust chamber which could be swiveled from side to side on two axes for pitch and yaw control, dispensing with the inefficient and somewhat fragile graphite vanes in the engine exhaust used by the V-2. The rotation of the engine on the gimbals was controlled by gyroscopic inertial reference; this type of guidance system was invented by Robert H. Goddard amongst others, who had partial success with it before World War II intervened. Roll control was by use of the turbopump exhaust to power reaction control system (RCS) jets on the fins. Compressed gas jets stabilized the vehicle after the main power cutoff. Similar devices are now extensively used in large, steerable rockets and in space vehicles. Another improvement was that initially the alcohol tank, and later the LOX tank also, were built integral with the outer skin, saving weight. The structure was also largely aluminum, as opposed to steel used in the V-2, thus reducing weight. Vikings 1 through 7 were about long, slightly longer than the V-2, but with a straight cylindrical body only in diameter, making the rocket quite slender. They had fairly large fins similar to those on the V-2. Vikings 8 through 14 were built with an enlarged airframe of improved design. The diameter was increased to , while the length was reduced to , altering the missile's "pencil shape". The fins were made much smaller and triangular. The added diameter meant more fuel and more weight, but the "mass ratio", of fueled to empty mass, was improved to about 5:1, a record for the time. == Flight history ==

First model RTV-N-12 (Vikings 1-7) Viking 1 On 3 May 1949, after two static firings (11 March and 25 April), the first Viking rocket took off from White Sands Missile Range in New Mexico. Its engine fired for 55 seconds, ten seconds short of the hoped-for maximum of 65, but the rocket flew on course and reached an altitude of —deemed a good start to the program. On 10 May 1950, from a site in the Pacific Ocean between Jarvis Island and Kiritimati, the fourth Viking became the only Viking rocket sounding rocket ever launched from a sea-going vessel. The flight was perfect, reaching , more than double that reached by Vikings 1 and 3. Viking 8, from White Sands Missile Range in New Mexico. The new Viking design was nearly half as wide again as its precursor, affording the highest fuel-to-weight ratio of any rocket yet developed. The tail fins no longer supported the weight of the rocket, as had previously been the case. Now, the Viking rocket rested on the base of its fuselage. This allowed the tail fins to be made much lighter, allowing the rocket to carry a heavier tank without weighing more than the first Viking design. On 6 June 1952, Viking 8 broke loose of its moorings during a static firing test. After it was allowed to fly for 55 seconds in the hope that it would clear the immediate area and thus pose no danger to ground crew, Nat Wagner, head of the "Cutoff group", delivered a command to the rocket to cease its thrust. 65 seconds later, the rocket crashed downrange to the southeast. Parts of Viking 12 were recovered and, along with parts built from the original blueprints, were used to create a full-size cutaway reconstruction of the rocket. This vehicle was donated by the Martin Marietta Corp in 1976 to the National Air and Space Museum, where it is on display. == Viking into Vanguard ==

The Viking series returned a bonanza of scientific information measuring temperature, pressure, density, composition and winds in the upper atmosphere and electron density in the ionosphere, and recording the ultraviolet spectra of the Sun, In October 1952, the General Assembly of the International Council of Scientific Unions (ICSU) adopted a proposal to undertake simultaneous observations of geophysical phenomena over the entire surface of the Earth. The International Geophysical Year (IGY), set for 1957–58, would involve the efforts of a multitude of nations in such farflung regions as the Arctic and Antarctica. In January 1955, Radio Moscow announced that the Soviet Union might be expected to launch a satellite in the near future. This announcement galvanized American space efforts; in the same month, the National Academy of Sciences' IGY committee established a Technical Panel on Rocketry to evaluate plans to orbit an American satellite. combined with upper stages to put a satellite into orbit, which could be tracked optically., == Table of flights ==

Vikings 1–12, excepting Viking 4, were flown from White Sands Missile Range, New Mexico. Vikings 13 and 14 were launched from Cape Canaveral. == See also ==