Satellite 1958 Alpha
|Organization||Army Ballistic Missile Agency|
|Major contractors||Jet Propulsion Laboratory|
|Mission type||Earth science|
|Launch date||February 1, 1958 at 03:48 UTC|
|Launch vehicle||Juno I|
|Mission duration||111 days|
|Decay||March 31, 1970|
|Webpage||NASA NSSDC Master Catalog|
|Mass||13. Earth science (also known as geoscience, the geosciences or the Earth Sciences) is an all-embracing term for the Sciences related to the planet EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 Events 1327 - Teenaged Edward III is crowned King of England, but the country is ruled by his mother Queen Year 1958 ( MCMLVIII) was a Common year starting on Wednesday (link will display full calendar of the Gregorian calendar. The Juno I was a satellite Launch vehicle, derived from and commonly confused with the Jupiter-C sounding rocket Orbital decay is the process of prolonged reduction in the height of a satellite's Orbit. Events 307 - After divorcing his wife Minervina, Constantine marries Fausta, the daughter of the retired Roman Emperor Year 1970 ( MCMLXX) was a Common year starting on Thursday (link shows full calendar of the Gregorian calendar. The International Designator (or NSSDC ID) is an international naming convention for Satellites It consists of the launch year a 3-digit incrementing launch number 97 kg (30. 80 lb)|
|Semimajor axis||7,832. The elements of an orbit are the parameters needed to specify that Orbit uniquely given a model of two point-masses obeying the Newtonian laws of motion and the 2 km (4,866. 6 miles)|
|Eccentricity||. In Astrodynamics, under standard assumptions, any Orbit must be of Conic section shape 139849|
|Inclination||33. Inclination in general is the Angle between a Reference plane and another plane or axis of direction 24°|
|Orbital period||114. The orbital period is the time taken for a given object to make one complete Orbit about another object 8 minutes|
|Apoapsis||2,550 km (1,585 miles)|
|Periapsis||358 km (222 miles)|
Explorer 1 (also known as satellite 1958 Alpha) was the first Earth satellite of the United States, launched on February 1, 1958 at 03:48 UTC from LC-26 at Cape Canaveral Air Force Station as part of the United States program for the International Geophysical Year and in response to the launch of the Soviet satellite Sputnik 1. In Celestial mechanics, an apsis, plural apsides (ˈæpsɨdɪːz is the point of greatest or least distance of the Elliptical orbit of an object from In Celestial mechanics, an apsis, plural apsides (ˈæpsɨdɪːz is the point of greatest or least distance of the Elliptical orbit of an object from This article is about artificial satellites For natural satellites also known as moons see Natural satellite. The United States of America —commonly referred to as the Events 1327 - Teenaged Edward III is crowned King of England, but the country is ruled by his mother Queen Year 1958 ( MCMLVIII) was a Common year starting on Wednesday (link will display full calendar of the Gregorian calendar. Cape Canaveral Air Force Station Launch Complex 26 (LC-26 was a launch site at Merritt Island, Florida. The Cape Canaveral Air Force Station (CCAFS is a detachment of the 45th Space Wing (45 SW Patrick AFB provides headquarters functions from the 45 SW a major airfield The International Geophysical Year or IGY was an international scientific effort that lasted from July 1, 1957, to December 31, 1958 The Union of Soviet Socialist Republics (USSR was a constitutionally Socialist state that existed in Eurasia from 1922 to 1991 Sputnik 1 ( "Спутник-1", "Satellite-1" ПС-1 ( PS-1, i It was the first spacecraft to detect the Van Allen radiation belt. The Van Allen radiation belt is a Torus of energetic Charged particles ( plasma) around Earth, held in place by Earth's Magnetic
The U. S. Earth satellite program began in 1954 as a joint United States Army and United States Navy proposal, called Project Orbiter, to put a scientific satellite into orbit during the International Geophysical Year. Year 1954 ( MCMLIV) was a Common year starting on Friday (link will display full 1954 Gregorian calendar) The United States Army is a military organization whose primary mission is to "provide necessary forces and capabilities. Project Orbiter was a proposed United States Spacecraft, an early competitor to Project Vanguard. In Physics, an orbit is the gravitationally curved path of one object around a point or another body for example the gravitational orbit of a planet around a star However, this proposal was rejected in 1955 by the Eisenhower administration in favor of the U. Year 1955 ( MCMLV) was a Common year starting on Saturday (link displays the 1955 Gregorian calendar) Election 1952 See also United States presidential election 1952 Dwight D S. Navy's Project Vanguard. Project Vanguard was a program managed by the United States Naval Research Laboratory (NRL which intended to launch the first Artificial satellite into  Following the launch of the Soviet satellite Sputnik 1 on October 4, 1957, the initial Project Orbiter program was revived as the Explorer program to catch up with the Soviet Union, beginning the Space Race. Events 610 - Heraclius arrives by ship from Africa at Constantinople, overthrows Byzantine Emperor Phocas Year 1957 ( MCMLVII) was a Common year starting on Tuesday (link displays the 1957 Gregorian calendar) The Explorer program was the United States 's first successful attempt to launch an artificial satellite. The Space Race was a competition of space exploration between the Soviet Union and the United States, which lasted roughly from 1957 to 1975 
Explorer 1 was designed and built by the Jet Propulsion Laboratory (JPL), while the Jupiter-C rocket was modified by the Army Ballistic Missile Agency (ABMA) to accommodate a satellite payload, the resulting rocket becoming known as the Juno I. The Jupiter-C was a type of Sounding rocket used for three Sub-orbital spaceflights conducted in 1956 and 1957 In military aircraft or space exploration the payload is the carrying capacity of an aircraft or space ship including as Cargo, Munitions scientific instruments The Juno I was a satellite Launch vehicle, derived from and commonly confused with the Jupiter-C sounding rocket The Jupiter-C design used for the launch had already been flight-tested in nose cone reentry tests for the Jupiter IRBM and was modified into Juno I. The term nose cone is used to refer to the forwardmost section of a Rocket, guided Missile or Aircraft. The PGM-19 Jupiter was a Medium-range ballistic missile (MRBM of the United States Air Force, removed from service by April 1963 An intermediate-range ballistic missile ( IRBM) is a Ballistic missile with a range of 3000-5500 km (1865-3420 miles between a Medium-range ballistic missile Working closely together, ABMA and JPL completed the job of modifying the Jupiter-C and building the Explorer 1 in 84 days. However, before work was completed the Soviet Union launched a second satellite, Sputnik 2, on November 3, 1957. Mission profile Sputnik 2 was launched into a 212 x 1660 km (132 x 1031 mile orbit with a period of 103 Events 644 - Umar ibn al-Khattab, the second Muslim Caliph, is killed by a Persian slave in Medina. The U. S. Navy's attempt to bring the first U. S. satellite into orbit failed with the launch of the Vanguard TV3 on December 6, 1957. Vanguard TV3 was the first attempt of the United States to launch a Satellite into Orbit around the Earth. Events 1060 - Béla I of Hungary is crowned king of Hungary 1240 - Mongol invasion of Rus: Kiev 
On February 1, 1958 at 03:48 UTC the Juno I rocket was launched putting Explorer 1 into orbit, which made Explorer 1 the first Earth satellite of the United States. Events 1327 - Teenaged Edward III is crowned King of England, but the country is ruled by his mother Queen Year 1958 ( MCMLVIII) was a Common year starting on Wednesday (link will display full calendar of the Gregorian calendar. The orbit had a perigee of 358 kilometers (222 mi) and an apogee of 2,550 kilometers (1,585 mi) having a period of 114. A mile is a unit of Length, usually used to measure Distance, in a number of different systems including Imperial units United States In Celestial mechanics, an apsis, plural apsides (ˈæpsɨdɪːz is the point of greatest or least distance of the Elliptical orbit of an object from 8 minutes.  The total weight of the satellite was 13. 97 kilograms (30. 80 lb), of which 8. 3 kg (18. 3 lb) were instrumentation. In comparison the first Soviet satellite Sputnik 1 weighed 83. 6 kg (184 lb). The instrument section at the front end of the satellite and the empty scaled-down fourth-stage rocket casing orbited as a single unit, spinning around its long axis at 750 revolutions per minute. The MGM-29 Sergeant was an American short-range solid fuel, Surface-to-surface missile developed at the Jet Propulsion Laboratory.
Explorer 1 was designed and built by the Jet Propulsion Laboratory of the California Institute of Technology under the direction of Dr. The California Institute of Technology (commonly referred to as Caltech) is a private, Coeducational research university located in Pasadena William H. Pickering. William Hayward Pickering ONZ KBE ( 24 December 1910 &mdash 15 March 2004) was a New Zealand born rocket It was the second satellite to carry a mission payload (Sputnik 2 was the first). The scientific instrumentation of the Explorer 1 satellite was designed and built under the direction of Dr. James Van Allen of the University of Iowa. James Alfred Van Allen ( September 7 1914 &ndash August 9, 2006) was an American space scientist at the University of Iowa The University of Iowa, is a major teaching service and Research university located on a campus in Iowa City Iowa, on the banks of the Iowa River It consisted of:
Because of the limited space available and the requirements for low weight, the Explorer 1 instrumentation was designed and built with simplicity and high reliability in mind. Electrical power was provided by mercury chemical batteries that made up approximately 40 % of the payload weight. A mercury battery (also called mercuric oxide battery, or mercury cell) is a non-rechargeable electrochemical battery, a Primary cell.
Data from the scientific instruments was transmitted to the ground by two antennas. An antenna is a Transducer designed to transmit or Receive electromagnetic waves In other words antennas convert electromagnetic waves into A 60 milliwatt dipole antenna consisting of two fiberglass slot antennas in the body of the satellite operating on 108. A dipole antenna, developed by Heinrich Rudolph Hertz around 1886, is an antenna with a center- fed Driven element for transmitting 03 MHz, and four flexible whips forming a 10 milliwatt turnstile antenna operating on 108. The hertz (symbol Hz) is a measure of Frequency, informally defined as the number of events occurring per Second. A turnstile antenna is a set of two Dipole antennas aligned at right angles to each other and fed 90 degrees out-of-phase 00 MHz. 
The Explorer 1 instrumentation payload used transistor electronics, consisting of both germanium and silicon devices. In Electronics, a transistor is a Semiconductor device commonly used to amplify or switch electronic signals Germanium (dʒɚˈmeɪniəm is a Chemical element with the symbol Ge and Atomic number 32 Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14 This was a very early time frame in the development of transistor technology, and represents the first documented use of transistors in the U. S. earth satellite program.  A total of 29 transistors were used in Explorer 1, plus additional ones in the Army's micrometeorite amplifier.
The external skin of the instrument section was painted in alternate strips of white and dark green to provide passive temperature control of the satellite. The proportions of the light and dark strips were determined by studies of shadow-sunlight intervals based on firing time, trajectory, orbit, and inclination. Trajectory is the path a moving object follows through space The object might be a Projectile or a Satellite, for example In Physics, an orbit is the gravitationally curved path of one object around a point or another body for example the gravitational orbit of a planet around a star Inclination in general is the Angle between a Reference plane and another plane or axis of direction
To the surprise of mission experts, satellite Explorer 1 changed rotation axis after launch. A rotation is a movement of an object in a circular motion A two- Dimensional object rotates around a center (or point) of rotation The elongated body of the spacecraft had been supposed to spin about its long (least-inertia) axis but refused to do so, and instead started precessing due to energy dissipation from flexible structural elements. The vis insita or innate force of matter is a power of resisting by which every body as much as in it lies endeavors to preserve in its present state whether it be of rest or of moving Precession refers to a change in the direction of the axis of a rotating object In Physics, dissipation embodies the concept of a Dynamical system where important mechanical modes such as Waves or Oscillations lose Energy Later it was understood that on general grounds, the body ends up in the spin state that minimizes the kinetic rotational energy (this being the maximal-inertia axis). The kinetic energy of an object is the extra Energy which it possesses due to its motion The rotational energy or angular kinetic energy is the Kinetic energy due to the rotation of an object and is part of its total kinetic energy. This motivated the first further development of the Eulerian theory of rigid body dynamics after nearly 200 years to address dissipation. 
Sometimes the instrumentation would report the expected cosmic ray count (approximately thirty counts per second) but sometimes it would show a peculiar zero counts per second. The Iowa group (under Van Allen) noted that all of the zero counts per second reports were from an altitude of 2,000+ km (1,250+ miles) over South America, while passes at 500 km (310 miles) would show the expected level of cosmic rays. The University of Iowa, is a major teaching service and Research university located on a campus in Iowa City Iowa, on the banks of the Iowa River South America is a Continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a Later, after Explorer 3, it was concluded that the original Geiger counter had been overwhelmed by strong radiation coming from a belt of charged particles trapped in space by the Earth's magnetic field, now known as the Van Allen radiation belt. Mission description Explorer 3 (satellite 1958 gamma was nearly identical to Explorer 1 in design and mission Earth 's magnetic field (and the surface magnetic field) is approximately a Magnetic dipole, with one pole near the North pole (see The Van Allen radiation belt is a Torus of energetic Charged particles ( plasma) around Earth, held in place by Earth's Magnetic The discovery of the Van Allen Belts by the Explorer satellites was considered to be one of the outstanding discoveries of the International Geophysical Year. The International Geophysical Year or IGY was an international scientific effort that lasted from July 1, 1957, to December 31, 1958
The acoustic micrometeorite detector detected 145 impacts of cosmic dust in 78,750 seconds. This leads for a twelve-day period to an impact rate of 8. 0 × 10-3 impacts m-2 s-1. 
The mercury batteries provided power that operated the high power transmitter for 31 days and the low-power transmitter for 105 days. Explorer 1 stopped transmission of data on May 23, 1958, when its batteries died, but remained in orbit for more than 12 years. Events 1430 - Siege of Compiègne: Joan of Arc is captured by the Burgundians while leading an army to relieve Compiègne Year 1958 ( MCMLVIII) was a Common year starting on Wednesday (link will display full calendar of the Gregorian calendar. It made a fiery reentry over the Pacific Ocean on March 31, 1970. Orbital decay is the process of prolonged reduction in the height of a satellite's Orbit. Events 307 - After divorcing his wife Minervina, Constantine marries Fausta, the daughter of the retired Roman Emperor Year 1970 ( MCMLXX) was a Common year starting on Thursday (link shows full calendar of the Gregorian calendar. Explorer 1 was the first of the long-running Explorer program, which as of November 2004 has launched 83 Explorer probes. The Explorer program was the United States 's first successful attempt to launch an artificial satellite. "MMIV" redirects here For the Modest Mouse album see " Baron von Bullshit Rides Again "
An identically-constructed flight backup of Explorer 1 is currently located in the Smithsonian Institution's National Air and Space Museum, Milestones of Flight Gallery. The Smithsonian Institution (smɪθsoʊnɪən is an educational and research institute and associated Museum complex administered and funded by the Government of The National Air and Space Museum (NASM of the Smithsonian Institution is a museum in Washington D