Scout

Scout, an acronym for Solid Controlled Orbital Utility Test system, was a four-stage solid fuel satellite system capable of launching a 385-pound satellite into a 500-mile orbit. There were 118 Scout launches with an overall 96 percent success rate SCOUT's reliability since 1968 was 98.3 percent and, since 1976, its launch success rate was 100 percent. Scout's honor roll includes 23 satellites launched for international space organizations. Payloads have been launched for the European Space Research Organization, for Germany, for the Netherlands, for France, for Italy, and for the United Kingdom. Through the years, Scout has launched 94 orbital missions, (27 Navy navigational and 67 scientific satellites), seven probe missions and 12 reentry missions.

SCOUT was America's first solid-fuel launch vehicle capable of orbiting a satellite. This launch vehicle had its beginnings as early as 1957. The U.S. needed a relatively inexpensive, quickly produced rocket to launch small research experiments, and Langley engineers were asked to design it. Their goal was to provide a launch vehicle capable of performing a variety of probe, re-entry and orbital missions with minimum preparation time.

The conception was complete in 1958, and Chance Vought Aircraft (later LTV Missiles and Electronics Group and subsequently Loral Vought Systems) of Dallas, prime contractor for the development of Scout systems.was placed under contract in March 1959 to build SCOUT vehicles. This was the beginning of a government/contractor relationship which lasted more than 35 years. The SCOUT program was managed from 1958 through Dec. 1990 by NASA's Langley Research Center, Hampton, Va. Program management was transferred to NASA's Goddard Space Flight Center, Greenbelt, Md., in Jan. 1991.

Scout's reliability stemmed from standardized procedures and configuration control and from its simple technology. The vehicle was built with off-the shelf hardware. Designers selected from an inventory of solid-fuel rocket motors produced for military programs: the first stage motor was a combination of the Jupiter Senior and the Navy Polaris; the second stage came from the Army Sergeant; and the third and fourth stage motors were designed by Langley engineers who adapted a version of the Navy Vanguard. The heatshield and fins were insulated with cork. The guidance system used simple gryos that cannot be reprogrammed after launch.

Since its early development, the configuration of Scout continued to evolve. Each of the motors was upgraded at least twice, and improvements in rocket engine design enabled the rocket to carry larger payloads. Even so, the final Scout G-1 configuration was very similar in appearance to that of the original vehicle.

Scout is 76 feet long, 45 inches in diameter and weighs 48,600 pounds. Its four solid propulsion rockets are joined by transition sections containing guidance, ignition, spin up motors and separation instrumentation necessary for flight.

The first stage is the Algol. It is 30 feet long and 45 inches in diameter. The motor burns for an average of 82 seconds with a maximum thrust of 140,000 pounds. At the bottom of this motor are the first stage altitude control jet vanes and fin tips, which steer the vehicle during initial launch.

The second stage, Castor, is 20 feet long and 30 inches in diameter. This stage fires for 41 seconds and develops 60,000 pounds of thrust.

Stage three rocket motor, the Antares, is 10 feet long and 30 inches in diameter. It burns for 48 seconds at 18,000 pounds of thrust. The second and third stage control is provided by hydrogen peroxide jets.

The fourth stage, Altair, is a mere five feet long and 20 inches in diameter. It burns for 34 seconds and develops 6000 pounds of thrust. Its control is provided by spin stabilization.

The heat shield covering the fourth stage and payload section is made of cork and fiberglass laminate.

The first SCOUT was launched from Goddard's Wallops Flight Facility, Wallops Island, Va., on July 1, 1960. The rocket carried a 193-pound (88-kilogram) payload as a probe test. On February 16, 1961, Scout became the first solid-fuel rocket to place a payload into orbit. The vehicle carried a 96-pound (44- kilogram) NASA atmospheric physics payload into orbit without incident.

Two launch sites were added in subsequent years. One, at the Western Test Range at Vandenberg Air Force Base, was added in 1962. Another was built on Italy's unique sea-based San Marco platform off the east coast of Kenya, Africa, the site of nine successful equatorial missions since 1967. Unlike most larger expendable rockets, the SCOUT was assembled and the payload is integrated and checked-out in the horizontal position prior to launch.

SCOUT capability grew dramatically over the years. Originally able to place a 131-pound (59-kilogram) payload in a nominal 345-mile (552-kilometer) circular orbit, SCOUT performance was improved, increasing its capability to put a 458- pound (208-kilogram) payload into the same orbit. The heaviest satellite ever placed in orbit by SCOUT was an Italian payload that weighed more than 600 pounds (270 kilograms) and was launched out of Africa. SCOUT increased its load-carrying capability 350 percent over that of the original vehicle with little increase in the size of its stages.

The last SCOUT launched a Miniature Sensor Technology Integration (MSTI) satellite. The satellite, designated MSTI-2, conducted tracking and Earth-observation experiments. Designed and built by Phillips Laboratory at Edwards Air Force Base, Calif., the MSTI program supported the Ballistic Missile Defense Organization's Theater Missile Defense Directive. A SCOUT launch vehicle launched the first MSTI satellite in Nov. 1992.

Resources

• Scout Vehicle Flights Complete Vehicle History - NASA KSC
• NASA News Release: Scout Launch Vehicle to Retire after 34 Years of ServiceMay 6, 1994 RELEASE: 94-72
• NASA'S Scout Launch Vehicle - NASA Goddard
• SLV-1 "BLUE SCOUT" Strategic Air Command Museum