Vanguard SLV-5, also called Vanguard Satellite Launch Vehicle-Five hoped to be the third successful flight of the American

Vanguard The vanguard (also called the advance guard) is the leading part of an advancing military formation. It has a number of functions, including seeking out the enemy and securing ground in advance of the main force. History The vanguard derives fr ...

rocket following the successful

Vanguard 2 Vanguard 2 (or Vanguard 2E before launch) is an Earth-orbiting satellite launched 17 February 1959 at 15:55:02 GMT, aboard a Vanguard SLV-4 rocket as part of the United States Navy's Project Vanguard. The satellite was designed to measure clo ...

satellite on rocket Vanguard SLV-4.

Background

Vanguard Satellite Launch Vehicle-5 (SLV-5) was designed to place two satellites in orbit, Vanguard 3A, a of diameter sphere (Sphere A) equipped with a magnetometer, and a of diameter

aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It ha ...

-coated round inflatable sphere (Sphere B), containing no instrumentation, but an air density measurement device, for optical tracking. Launched in April 1959, the mission failed when the second stage failed to operate following first-stage separation. The satellites and third stage tumbled into the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

several hundred kilometers off the coast after about 500 seconds of flight.

Launch vehicle

Vanguard was the designation used for both the launch vehicle and the satellite. The first stage of the three-stage Vanguard Test Vehicle was powered by a General Electric X-405 thrust liquid rocket engine, propelled by of

kerosene Kerosene, paraffin, or lamp oil is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Its name derives from el, κηρός (''keros'') meaning "wax", and was regi ...

(

RP-1 RP-1 (alternatively, Rocket Propellant-1 or Refined Petroleum-1) is a highly refined form of kerosene outwardly similar to jet fuel, used as rocket fuel. RP-1 provides a lower specific impulse than liquid hydrogen (LH2), but is cheaper, is s ...

) and

liquid oxygen Liquid oxygen—abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries—is the liquid form of molecular oxygen. It was used as the oxidizer in the first liquid-fueled rocket invented in 1926 by Robert H. Goddard, an app ...

, with helium pressurant. It also held of

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%� ...

. It was finless, tall, in diameter, and had a launch mass of approximately . The second stage was a high, of diameter

Aerojet General AJ-10 Aerojet was an American rocket and missile propulsion manufacturer based primarily in Rancho Cordova, California, with divisions in Redmond, Washington, Orange and Gainesville in Virginia, and Camden, Arkansas. Aerojet was owned by GenCorp. In ...

liquid engine burning

Unsymmetrical dimethylhydrazine Unsymmetrical dimethylhydrazine (UDMH; 1,1-dimethylhydrazine, НДМГ or codenamed Geptil) is a chemical compound with the formula H2NN(CH3)2 that is used as a rocket propellant. It is a colorless liquid, with a sharp, fishy, ammonia-like smell ...

(UDMH) and

White Inhibited Fuming Nitric Acid Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nitric ...

(WIFNA) with a

helium Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. ...

pressurant tank. It produced a thrust of and had a launch mass of approximately . This stage contained the complete guidance and control system. A solid-propellant rocket with of thrust (for 30 seconds burn time) was developed by the

Grand Central Rocket Company The Lockheed Propulsion Company was a division of the Lockheed Aircraft Corporation located at 1500 Crafton Avenue in the Mentone, California area northeast of Redlands, California, adjacent to the Santa Ana River, from 1961 to 1975. It developed, ...

to satisfy third-stage requirements. The stage was high, in diameter, and had a launch mass of . The thin steel casing for the third stage had a hemispherical forward dome with a shaft at the center to support the satellite and an aft dome fairing into a steel exit nozzle. The total height of the vehicle with the satellite fairing was about . The payload capacity was to a Earth orbit. A nominal launch would have the first stage firing for 144 seconds, bringing the rocket to an altitude of , followed by the second stage burn of 120 seconds to , whereupon the third stage would bring the satellite to orbit. This was the same launch vehicle configuration, with minor modifications, as used for

Vanguard TV-3 Vanguard TV-3 (also called Vanguard Test Vehicle-Three), was the first attempt of the United States to launch a satellite into orbit around the Earth, after the successful Soviet launches of Sputnik 1 and Sputnik 2. Vanguard TV-3 was a small s ...

and all succeeding Vanguard flights up to and including

Vanguard SLV-6 Vanguard SLV-6, also called Vanguard Satellite Launch Vehicle-Six, hoped to be the third successful flight of the American Vanguard rocket following the successful Vanguard 2 satellite on rocket Vanguard SLV-4. Vanguard Satellite Launch Vehicl ...

Spacecraft

Magnetic Field Satellite

The primary objective of the Magnetic Field Satellite (Sphere A) was to determine the source of magnetic storms - to determine if they occur due to electric currents in the ionosphere or from currents at much greater distances. A secondary objective was to obtain data on the daily cycle of magnetic field variations, thus providing a highly accurate map of the Earth's main magnetic field in certain regions of space. The Magnetic Field Satellite was a of diameter

fiberglass Fiberglass (American English) or fibreglass ( Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass clo ...

sphere with a 6.2 cm (2.44 inch) of diameter fiberglass cylindrical boom protruding from the top, and a diameter

magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ta ...

cylinder protruding from the base. Four spring-actuated antennas were mounted to the satellites equator, equally spaced. Each antennas was in diameter at the base and at the tip. The interior of the satellite held a cylindrical magnesium container with two pressure-tight compartments. The lower compartment held the batteries, and the upper compartment held the magnetometer electronics, an 80

milliwatt The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named after James Wat ...

telemetry transmitter operating at 108.3

MHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one he ...

, a 10 milliwatt

Minitrack The Minitrack Network was the first U.S. satellite tracking network to become operational, in 1957. It was used to track the flights of Sputnik, Vanguard, Explorer, and other early space efforts. Minitrack was the progenitor of Spacecraft Trackin ...

beacon transmitter at 108.00 MHz, and a command receiver. The magnetometer was a proton precessional magnetometer. The magnetometer sensing unit was mounted in the outer end of the fiberglass boom. The design of the satellite required non-magnetic materials, including special batteries.

Sub-Satellite

The Sub-Satellite (Sphere B) objective was to provide data on air density in the outer limits of the

atmosphere of Earth The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing fo ...

. A later version of the Magnetic Field Satellite was successfully launched as Vanguard 3 (1959 Eta 1). The Sub-Satellite was stored, uninflated, in a fiberglass container beneath the Magnetic Field Satellite, along with a small tank containing

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

at a pressure of . On separation of the Magnetic Field Satellite, a preset latch would release the gas into the Sub-Satellite, inflating it and pushing it free of the spent third stage. Upon inflation, the Sub-Satellite would be a 76.2 cm (30 inch) diameter aluminum-coated mylar balloon. It contained no instrumentation and was designed to be optically tracked from

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

to provide data on the density of the

upper atmosphere Upper atmosphere is a collective term that refers to various layers of the atmosphere of the Earth above the troposphere and corresponding regions of the atmospheres of other planets, and includes: * The mesosphere, which on Earth lies between th ...

by measuring its effect on the satellite orbit.

Launch

Vanguard SLV-5 launched on 14 April 1959 at 02:49:46

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 ...

(09:49:46 p.m. EST, 13 April 1959), from Launch Complex 18A (LC-18A) at the

Cape Canaveral Air Force Station Cape Canaveral Space Force Station (CCSFS) is an installation of the United States Space Force's Space Launch Delta 45, located on Cape Canaveral in Brevard County, Florida. Headquartered at the nearby Patrick Space Force Base, the statio ...

(CCAFS). At separation of the first stage 142.0 seconds after launch, caused the second stage engine to ignite while still attached to the first stage. Pressure from the engine exhaust pushed the thrust chamber to the limit of the gimbal stops, breaking them and causing loss of

attitude control Attitude control is the process of controlling the orientation of an aerospace vehicle with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc. Controlling vehicle ...

in flight. The pitch-attitude control of the second stage was lost due to large side forces acting on the second stage exhaust nozzle caused by back pressure built up in the interstage compartment. The third stage and satellites were thrown from the tumbling second stage. The second stage tumbled and the resultant forces caused a premature separation of the third stage and payload. Data was received from them until impact into the

eight minutes after liftoff.NASA, Aeronautics and Astronautics Chronology, 1958

Background

Launch vehicle

Spacecraft

Magnetic Field Satellite

Sub-Satellite

Launch

See also

References

Further reading