Explorer S-55 was an American satellite launched by

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

on 30 June 1961, as part of the

Explorer program The Explorers program is a NASA exploration program that provides flight opportunities for physics, geophysics, heliophysics, and astrophysics investigations from space. Launched in 1958, Explorer 1 was the first spacecraft of the United Stat ...

. Explorer S-55, was launched using a

Scout X-1 Scout X-1 was an American expendable launch system and sounding rocket which was flown seven times between August 1960 and October 1961. Four orbital and three suborbital launches were made, with four of the launches resulting in failures. The ...

launch vehicle A launch vehicle or carrier rocket is a rocket designed to carry a payload (spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pad, launch pads, supported by a missile launch contro ...

from the

Wallops Flight Facility Wallops Flight Facility (WFF) is a rocket launch site on Wallops Island on the Eastern Shore of Virginia, United States, just east of the Delmarva Peninsula and approximately north-northeast of Norfolk. The facility is operated by the Goddard ...

(WFF). Its mission was to evaluate the launch vehicle, and investigate

micrometeoroid A micrometeoroid is a tiny meteoroid: a small particle of rock in space, usually weighing less than a gram. A micrometeorite is such a particle that survives passage through Earth's atmosphere and reaches Earth's surface. The term "micrometeoroid ...

impact and penetration. The mission failed because the third stage failed to ignite and the spacecraft did not achieve orbit.

Mission

The objectives of the flight were to test vehicle performance and guidance and to investigate the nature and effects of

s on the spacecraft systems. The scientific instrumentation consisted of cadmium sulfide-cell, wire-grid,

piezoelectric Piezoelectricity (, ) is the electric charge that accumulates in certain solid materials—such as crystals, certain ceramics, and biological matter such as bone, DNA, and various proteins—in response to applied Stress (mechanics), mechanical s ...

, pressurized-cell, and foil-type micrometeoroid detectors.

Spacecraft

The spacecraft was a cylinder. Weighing , including its fourth stage and transition section, its objective was to test the performance of a Scout launch vehicle and its guidance system and to investigate the nature and effects of space flight on

s. Its payload was a cylinder, almost covered by five types of micometeoroid impact detectors, two transmitters, solar cells and nickel-cadmium batteries.

Launch

Explorer S-55 was launched on 30 June 1961, at 17:09

GMT Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory in Greenwich, London, counted from midnight. At different times in the past, it has been calculated in different ways, including being calculated from noon; as a cons ...

, in using a

. The mission failed because the third stage failed to ignite and the spacecraft did not achieve orbit.

References

{{Reflist, 30em Satellites of the United States Explorers Program

Mission

Spacecraft

Launch

See also

References