Juno I

Juno I
	Juno I satellite launch vehicle carrying Explorer 2. (USAF)
Function	Orbital launch vehicle
Manufacturer	Chrysler for the ABMA
Country of origin	United States
Size
Height	21.2 m (70 ft)
Diameter	1.78 m (5 ft 10 in)
Mass	29,060 kg (64,070 lb)
Stages	4
Capacity
Payload to LEO
Mass	11 kg (24 lb)
Launch history
Status	Retired
Launch sites	LC-5 and 26A, Cape Canaveral Missile Annex, Florida
Total launches	6
Success(es)	3
Failure(s)	3
First flight	January 31, 1958; (First orbit: Explorer 1 January 31, 1958)
Last flight	October 23, 1959
First stage – Redstone (stretched)
Powered by	1 Rocketdyne A-7
Maximum thrust	42,439 kgf (416.18 kN; 93,560 lbf)
Specific impulse	235 s (2.30 km/s)
Burn time	155 seconds
Propellant	Hydyne/LOX
Second stage – Baby Sergeant cluster
Powered by	11 Solid
Maximum thrust	7,480 kgf (73.4 kN; 16,500 lbf)
Specific impulse	214 s (2.10 km/s)
Burn time	6 seconds
Propellant	Polysulfide-aluminum and ammonium perchlorate (Solid)
Third stage – Baby Sergeant cluster
Powered by	3 Solid
Maximum thrust	2,040 kgf (20.0 kN; 4,500 lbf)
Specific impulse	214 s (2.10 km/s)
Burn time	6 seconds
Propellant	Polysulfide-aluminum and ammonium perchlorate (Solid)
Fourth stage – Baby Sergeant
Powered by	1 Solid
Maximum thrust	680 kgf (6.7 kN; 1,500 lbf)
Specific impulse	214 s (2.10 km/s)
Burn time	6 seconds
Propellant	Polysulfide-aluminum and ammonium perchlorate (Solid)
	[edit on Wikidata]

The Juno I was a four-stage American booster rocket that launched America's first satellite, Explorer 1, in 1958. A member of the Redstone rocket family, it was derived from the Jupiter-C sounding rocket. It is commonly confused with the Juno II launch vehicle, which was derived from the PGM-19 Jupiter medium-range ballistic missile.

History

The Explorer Project began as a U.S. Army proposal (Project Orbiter) to place a "civilian" artificial satellite into orbit during the International Geophysical Year. The proposal was based on the Redstone missile vehicle. Although that proposal was rejected in favor of the U.S. Navy's Project Vanguard, which made the first sub-orbital flight Vanguard TV0 in December 1956, the Soviet Union's launch of Sputnik 1 on October 4, 1957 (and the resulting "Sputnik crisis") and the failure of the Vanguard 1 launch attempt resulted in the Army program being funded to match the Soviet space achievements.

The rocket family is named for the Roman goddess and queen of the gods Juno for its position as the satellite-launching version of the Jupiter-C. The name was proposed by JPL Director Dr. William Pickering in November 1957. The September 1956 test launch of a Jupiter-C for the Army Ballistic Missile Agency could have been the world's first satellite launch. Had a fourth stage been loaded and fueled, the nose cone would have overshot the target and entered orbit. Such a launch did not occur until early 1958 when a Juno 1 successfully launched the first United States satellite, Explorer 1 after the Soviet Union's Sputnik 1 in October 1957.^[2]

Juno-I launched the Explorer 1 satellite on January 31, 1958, becoming the first U.S. satellite, as well as discovering the Van Allen radiation belt.

Vehicle

The Juno I consisted of a Jupiter-C first stage, based on the Redstone missile; with three additional solid fuel 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 8 kilometres per second (29,000 km/h; 18,000 mph). The tub along with the fourth stage were set spinning while the rocket was on the launch pad to provide gyroscopic force in lieu of a guidance system that would have required vanes, gimbals, or vernier motors. This multi-stage system, designed by Wernher von Braun 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 (21.2 meters), with the added fourth-stage booster of the Juno I being enclosed inside the nose cone of the third stage.

Launch history

Following the successful launch of Explorer 1 on January 31, 1958, the first U.S. satellite, Juno I made five more launches before being retired in favor of Juno II. Although Juno I's launch of the Explorer 1 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,^[1] giving the Juno I vehicle a mission total success ratio of 50%. The Juno I vehicle was replaced by the Juno II 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 series. With the relative success of the Juno I program, von Braun developed the Juno II, using a PGM-19 Jupiter first stage, rather than a Redstone.

Flight No.	Date / time (UTC)	Rocket, Configuration	Launch site	Payload	Payload mass	Orbit	User	Launch outcome
1	February 1, 1958 03:47	Juno I	LC-26A	Explorer 1	22 kg	LEO	ABMA	Success
1	Maiden launch of Juno I. First American satellite launched. Explorer 1 ceased transmission of data on May 23, 1958 when its batteries died, but remained in orbit for more than 12 years. It made a fiery reentry over the Pacific Ocean on March 31, 1970.
2	March 5, 1958 18:27	Juno I	LC-26A	Explorer 2	23 kg	LEO	ABMA	Failure
2	Fourth stage did not ignite.
3	March 26, 1958 17:38	Juno I	LC-5	Explorer 3	23 kg	LEO	ABMA	Success
3	Down June 28, 1958.
4	July 26, 1958 15:00	Juno I	LC-5	Explorer 4	29 kg	LEO	ABMA	Success
4	Down October 23, 1959.
5	August 24, 1958 06:17	Juno I	LC-5	Explorer 5	29 kg	LEO	ABMA	Failure
5	Booster collided with second stage after separation, causing upper stage firing angle to be off.
6	October 23, 1958 03:21	Juno I	LC-5	Beacon satellite	23 kg	LEO	ABMA	Failure
6	Second stage separated prematurely from booster.

Gallery

Juno I carrying Explorer 3
Juno I with Explorer I mock-up at the Kennedy Space Center rocket garden

References

Source: Data Sheet, Department of Astronautics, National Air and Space Museum, Smithsonian Institution.

^ ^a ^b J. Boehm, H.J. Fichtner, and Otto A. Hoberg, EXPLORER SATELLITES LAUNCHED BY JUNO 1 AND JUNO 2 VEHICLES, NASA Report.
^ Bello, Francis (1959). "The Early Space Age". Fortune. Archived from the original on November 3, 2013. Retrieved June 5, 2012.

[Boehm-NASA-1] J. Boehm, H.J. Fichtner, and Otto A. Hoberg, EXPLORER SATELLITES LAUNCHED BY JUNO 1 AND JUNO 2 VEHICLES, NASA Report.

[bello1959-2] Bello, Francis (1959). "The Early Space Age". Fortune. Archived from the original on November 3, 2013. Retrieved June 5, 2012.

[1]

[2]

v t e Orbital launch systems
List of orbital launch systems Comparison of orbital launch systems
Current	Angara 1.2 A5 Ariane 6 Atlas V Ceres 1 1S Chollima-1 Electron Falcon 9 Block 5 Falcon Heavy Firefly Alpha Gravity-1 GSLV H-IIA H3 Hyperbola-1 Jielong 1 3 KAIROS^† Kaituozhe 2 Kinetica 1 Kuaizhou 1 1A 11 Long March 2C 2D 2F 3A 3B/E 3C 4B 4C 5 5B 6 6A 7 7A 8 11 11H LVM3 Minotaur I IV V C Nuri OS-M1^† Pegasus XL Proton-M PSLV Qaem 100 Qased RS1^† Shavit 2 Simorgh SLS Block 1 Soyuz-2 2.1a / STA 2.1b / STB 2-1v SSLV Starship Tianlong-2 Unha Vega C Vulcan Centaur Zhuque 2
In development	Antares 330 Bloostar Cyclone-4M Deca Epsilon S Eris Gravity-2 Hyperbola-2 Irtysh Kuaizhou 21 31 Long March 9 10 12 Miura 5 MLV Neutron New Glenn New Line 1 NGLV Nova OS-M 2 4 Orbex Prime Pallas-1 Red Dwarf SLS Block 1B Block 2 Soyuz-7 Terran R Tianlong-3 VLM Vega E Zero Zhuque 3 Zuljanah
Retired	Antares 110 120 130^† 230 230+ Ariane 1 2 3 4 5 ASLV Athena I II Atlas B D E/F G H I II III LV-3B SLV-3 Able^† Agena Centaur Black Arrow Conestoga^† Delta A B C D E G J L M N 0100 1000 2000 3000 4000 5000 II III IV IV Heavy Diamant Dnepr Energia Epsilon Europa I^† II^† Falcon 1 Falcon 9 v1.0 v1.1 v1.2 "Full Thrust" Feng Bao 1 GSLV Mk I H-I H-II H-IIB Juno I Juno II Kaituozhe-1 Kosmos original 1 2/2I 3 3M Lambda 4S LauncherOne Long March 1 1D^† 2A 2E 3 3B 4A Mu 4S 3C 3H 3S 3SII V N1^† N-I N-II Naro-1 Paektusan^† Pilot-2^† R-7 Luna Molniya M L Polyot Soyuz original FG L M U U2 Soyuz/Vostok Sputnik Voskhod Vostok L K 2 2M R-29 Shtil' Volna^† Rocket 3 Safir 1 1A 1B Saturn I IB V Scout X-1 Blue Scout II^† X-2^† X-2M X-3 X-3M X-4 X-2B^† B A B-1 D-1 A-1 E-1 F-1 G-1 Shavit original 1 SLV Space Shuttle SPARK^† Sparta SS-520 Start-1 Terran 1^† Thor Able Ablestar 1 2 Agena A B D Burner 1 2 Delta DSV-2U Thorad-Agena SLV-2G SLV-2H Titan II GLV IIIA IIIB IIIC IIID IIIE 34D 23G CT-3 IV Tsyklon R-36-O original 2 3 Universal Rocket UR-500 Proton Proton-K Rokot Strela Vanguard Vega original VLS-1^† Zenit 2 2M 2FG 3SL 3SLB 3F Zhuque 1^†
Classes	Sounding rocket Small-lift launch vehicle Medium-lift launch vehicle Heavy-lift launch vehicle Super heavy-lift launch vehicle
This Template lists historical, current, and future space rockets that at least once attempted (but not necessarily succeeded in) an orbital launch or that are planned to attempt such a launch in the future Symbol ^† indicates past or current rockets that attempted orbital launches but never succeeded (never did or has yet to perform a successful orbital launch)

v t e Orbital launch systems developed in the United States
Active	Atlas V**^†† Electron Falcon 9 Block 5 Falcon Heavy Firefly Alpha Minotaur I IV V C Pegasus XL RS1^† SLS Block 1 Vulcan Centaur
In development	Antares 330 Daytona I MLV New Glenn Neutron Nova Red Dwarf SLS Block 1B Block 2 Starship Terran R
Retired	Antares 110/120/130/230/230+^††† Athena I II Atlas B D E/F G H I II III LV-3B SLV-3 Able Agena Centaur Conestoga Delta A B C D E G J L M N 0100 1000 2000 3000 4000 5000 II III IV IV Heavy Falcon 1 Falcon 9 v1.0 v1.1 v1.2 "Full Thrust" H-I* Juno I Juno II LauncherOne N-I* N-II* Pilot Rocket 3 Saturn I IB V Scout Space Shuttle SPARK Sparta Terran 1 Thor Able Ablestar Agena Burner Delta DSV-2U Thorad-Agena Titan II GLV IIIA IIIB IIIC IIID IIIE 34D 23G CT-3 IV Vanguard
* - Japanese projects using US rockets or stages ** - uses Russian engines ^† - never succeeded ^†† - no new orders accepted ^††† - used Ukrainian first stage