Arcas

Arcas (originally "All-Purpose Rocket for Collecting Atmospheric Soundings", also designated Big Boy Rocket or "PWN-6") was the designation of an American sounding rocket, developed by the Atlantic Research Corp. (now Atlantic Richfield Company (ARCO)), Alexandria, Va. The Arcas sounding rocket is an unguided vehicle with a diameter of 4.5 inches designed to carry payloads of 12 pounds or less to heights in excess of 200,000 feet when launched from sea level. It launched between July 31, 1959, and August 9, 1991, at least 421 times. The Arcas has a maximum flight altitude of 52 kilometers, a takeoff thrust of 1.5 kN, a takeoff weight of 34 kilograms, and a diameter of 11 centimeters. The Arcas was 2.30 m long and had a fin span of 0.33 m. History A 1957 Stanford Research Institute study proposed a small single-stage sounding rocket to measure high-altitude winds to determine the spread of radioactive fallout. The U. S. Office of Naval Research and the Air Force Research Center awarded Atlantic Research Corporation a contract to develop this sounding rocket, known as "Kitty" in January 1958. ARC designed the Arcas rocket, the first of which was ready for flight tests in late 1958. By the end of 1960, more than 400 Arcas rockets had been launched. Engine The Arcas was powered by a slow-burning SR45-AR-1 solid-propellant motor. Since the rocket diameter was larger than the nozzle diameter of the engine, the aft end of the rocket ended in a tapered "boat tail", to decrease the subsonic drag.