The Juno I was a four-stage American

space launch vehicle A launch vehicle is typically a rocket-powered vehicle designed to carry a payload (a crewed spacecraft or satellites) from Earth's surface or lower atmosphere to outer space. The most common form is the ballistic missile-shaped multist ...

, used to launch lightweight payloads into

low Earth orbit A low Earth orbit (LEO) is an geocentric orbit, orbit around Earth with a orbital period, period of 128 minutes or less (making at least 11.25 orbits per day) and an orbital eccentricity, eccentricity less than 0.25. Most of the artificial object ...

. The launch vehicle was used between January 1958 to December 1959. The launch vehicle is a member of the Redstone launch vehicle family, and was derived from the

Jupiter-C The Jupiter-C was an American research and development vehicle developed from the Jupiter-A. Jupiter-C was used for three Uncrewed vehicle, uncrewed sub-orbital spaceflights in 1956 and 1957 to test Re-entry vehicle, re-entry nosecones that were ...

sounding rocket A sounding rocket or rocketsonde, sometimes called a research rocket or a suborbital rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The rockets are often ...

. It is commonly confused with the

Juno II Juno II was an American space launch vehicle used during the late 1950s and early 1960s. It was derived from the Jupiter missile, which was used as the first stage. Development Solid-fueled rocket motors derived from the MGM-29 Sergeant we ...

launch vehicle, which was derived from the

PGM-19 Jupiter The PGM-19 Jupiter was the first nuclear weapon, nuclear armed, medium-range ballistic missile (MRBM) of the United States Air Force (USAF). It was a liquid-propellant rocket using RP-1 fuel and Liquid oxygen, LOX oxidizer, with a single Rocketd ...

medium-range ballistic missile A medium-range ballistic missile (MRBM) is a type of ballistic missile with medium range (aeronautics), range, this last classification depending on the standards of certain organizations. Within the United States Department of Defense, U.S. D ...

. In 1958, a Juno I launch vehicle was used to launch America's first satellite,

Explorer 1 Explorer 1 was the first satellite launched by the United States in 1958 and was part of the U.S. participation in the International Geophysical Year (IGY). The mission followed the first two satellites, both launched by the Soviet Union duri ...

History

Developed as a part of the Explorer Project, the original goal for the launch vehicle was to place an

artificial satellite A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scienti ...

into

orbit In celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an ...

. Following the

Soviet Union The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

's launch of

Sputnik 1 Sputnik 1 (, , ''Satellite 1''), sometimes referred to as simply Sputnik, was the first artificial Earth satellite. It was launched into an elliptical low Earth orbit by the Soviet Union on 4 October 1957 as part of the Soviet space program ...

on October 4, 1957 (and the resulting "

Sputnik crisis The Sputnik crisis was a period of public fear and anxiety in Western nations about the perceived technological gap between the United States and Soviet Union caused by the Soviets' launch of '' Sputnik 1'', the world's first artificial sate ...

") and the failure of the

Vanguard 1 Vanguard 1 (Harvard designation: 1958-Beta 2, COSPAR ID: 1958-002B ) is an American satellite that was the fourth artificial Earth-orbiting satellite to be successfully launched, following Sputnik 1 Sputnik 1 (, , ''Satellite 1''), ...

launch attempt, the program received funding to match the Soviet space achievements. The launch vehicle family name was suggested in November 1957 by

Jet Propulsion Laboratory The Jet Propulsion Laboratory (JPL) is a Federally funded research and development centers, federally funded research and development center (FFRDC) in La Cañada Flintridge, California, Crescenta Valley, United States. Founded in 1936 by Cali ...

(JPL) Director Dr. William Pickering, who proposed the name Juno, after the Roman goddess and queen of the gods, as well as for its position as the satellite-launching version of the

. The fourth stage for the Juno I launch vehicle was derived following the September 1956 test launch of a Jupiter-C for the

Army Ballistic Missile Agency The Army Ballistic Missile Agency (ABMA) was formed to develop the U.S. Army's first large ballistic missile. The agency was established at Redstone Arsenal on 1 February 1956, and commanded by Major General John B. Medaris with Wernher v ...

, which could have been the world's first satellite launch, had a fourth stage been loaded and fueled. A fourth stage would have allowed the nose cone to overshoot the target and enter orbit. The first launch of a Juno I launch vehicle was in early 1958, with the successful launch of

satellite on February 1, 1958, at 03:47:56 GMT, after the Soviet Union's

on October 4, 1957. The launch had been scheduled for January 29, 1958, but was scrubbed twice. Explorer 1 was the first U.S. satellite, and it confirmed the existence of the

Van Allen radiation belt The Van Allen radiation belt is a zone of energetic charged particles, most of which originate from the solar wind, that are captured by and held around a planet by that planet's magnetosphere. Earth has two such belts, and sometimes others ma ...

. Following the first successful launch, five more Juno I launch attempts occurred with two successes and three failures. The final launch attempt was on October 23, 1958, from Cape Canaveral Launch Pad 5, which ended in failure.

Launch vehicle

The Juno I consisted of a

first stage, based on the Redstone missile; with three additional

solid fuel Solid fuel refers to various forms of solid material that can be burnt to release energy, providing heat and light through the process of combustion. Solid fuels can be contrasted with liquid fuels and gaseous fuels. Common examples of solid fu ...

stages based on the Sergeant missile to provide the added impulse to achieve orbit. The fourth stage was mounted on top of the "tub" of the third stage, and fired after third-stage burnout to boost the payload and fourth stage to an orbital velocity of , with an acceleration of 25–51 g. The tub along with the fourth stage were set spinning while the launch vehicle was on the launch pad to provide gyroscopic force in lieu of a guidance system that would have required

thrust vectoring Thrust vectoring, also known as thrust vector control (TVC), is the ability of an aircraft, rocket or other vehicle to manipulate the direction of the thrust from its engine(s) or motor(s) to Aircraft flight control system, control the Spacecra ...

, vernier thrusters, or a

reaction control system A reaction control system (RCS) is a spacecraft system that uses Thrusters (spacecraft), thrusters to provide Spacecraft attitude control, attitude control and translation (physics), translation. Alternatively, reaction wheels can be used for at ...

. The booster guidance package (with the tub attached) separated from the first stage after burnout to provide attitude control until second stage ignition. This multi-stage system, designed by

Wernher von Braun Wernher Magnus Maximilian Freiherr von Braun ( ; ; 23 March 191216 June 1977) was a German–American aerospace engineer and space architect. He was a member of the Nazi Party and '' Allgemeine SS'', the leading figure in the development of ...

in 1956 for his proposed Project Orbiter, obviated the need for a guidance system in the upper stages. It was the simplest method for putting a payload into orbit but having no upper-stage guidance, the payload could not achieve a precise orbit. Both the four-stage Juno I and three-stage Jupiter-C launch vehicles were the same height (), with the added fourth-stage booster of the Juno I being enclosed inside the nose cone of the third stage.

Launch history

Juno I was launched six times by ABMA in 1958, intending to place satellites in LEO. Following the successful launch of

on February 1, 1958, the first U.S. satellite, Juno I made five more launches before being retired in favor of

. Although Juno I's launch of the

satellite was a huge success for the U.S. space program, only two of its remaining five flights were successful, Explorer 3 and Explorer 4, giving the Juno I vehicle a mission total success ratio of 50%. The Juno I vehicle was replaced by the

in 1959. The American public was happy and relieved that America had finally managed to launch a satellite after the launch failures in the Vanguard and

Viking Vikings were seafaring people originally from Scandinavia (present-day Denmark, Norway, and Sweden), who from the late 8th to the late 11th centuries raided, pirated, traded, and settled throughout parts of Europe.Roesdahl, pp. 9� ...

series. With the relative success of the Juno I program, von Braun developed the

, using a

first stage, rather than a Redstone.

Gallery

File:Launch of Jupiter C with Explorer 1.jpg, Juno I RS-29 UE launching

File:Juno-1 explorer-2.jpg, Juno I RS-26 UV launching Explorer 2 File:Explorer III.jpg, Juno I RS-24 UT launching Explorer 3 File:Juno-1 (Explorer 4).jpg, Juno I RS-44 TT with Explorer 4 File:Juno-1 44.JPG, Juno I RS-44 TT launching Explorer 4 File:Juno I with Beacon 1.jpg, Juno I RS-49 HE with BEACON 1 File:Juno I RS CC-49.jpg, Juno I RS-49 HE launching BEACON 1 File:Juno I with Explorer I mock-up at KSC.jpg, Juno I with Explorer 1 mock-up at the Kennedy Space Center rocket garden File:NationalAirAndSpaceMuseum 10290004.jpg, Juno I with Explorer 1 mock-up at the

National Air and Space Museum The National Air and Space Museum (NASM) of the Smithsonian Institution is a museum in Washington, D.C., in the United States, dedicated to history of aviation, human flight and space exploration. Established in 1946 as the National Air Museum, ...

References

External links

* Source: Data Sheet, Department of Astronautics,

Smithsonian Institution The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums, Education center, education and Research institute, research centers, created by the Federal government of the United States, U.S. government "for the increase a ...