Editing Jupiter-C

{{Short description|Part of the Redstone rocket family}}
{{More citations needed|date=October 2007}}
{{Infobox rocket
| image    =Jupiter c pad.jpg
| caption  =Jupiter-C on the launch pad at [[Cape Canaveral Air Force Station|Cape Canaveral]]
| name     =Jupiter-C
| function =[[Sounding rocket]]
| manufacturer =[[Chrysler]] for the ABMA
| country-origin = United States
| height   =  {{convert|69.9|ft|m}}
| diameter =  {{convert|5.8|ft|m}}
| mass     =  {{convert|64,000|lb|kg}}
| stages   =3
| capacities = 
  {{Infobox rocket/payload
  |location = [[Sub-orbital]]
  |kilos    = {{cvt|11|kg}}
  }}
| status   =Retired
| sites    =[[Cape Canaveral Air Force Station Launch Complex 5|LC-5]] and [[Cape Canaveral Air Force Station Launch Complex 6|6]], [[Cape Canaveral Air Force Station|Cape Canaveral Missile Annex, Florida]]
| launches =3 (all suborbital)
| success  =1 (suborbital)
| fail     =1 (suborbital)
| partial  =1 (suborbital)
| first    =September 20, 1956
| last     =August 8, 1957
| stagedata    = 
  {{Infobox rocket/stage
  |type       = stage
  |stageno    = First
  |name       = [[Redstone (rocket)|Redstone]] (stretched)
  |engines    = 1 North American Aviation (Rocketdyne) 75-110-[[A-7 (rocket engine)|A-7]]
  |thrust     = {{convert|42439|kgf|lbf kN|abbr=on|order=flip}}
  |SI         = {{cvt|235|isp}}
  |burntime   = 155 s
  |fuel       = [[LOX]]/[[Hydyne]]
  }}
  {{Infobox rocket/stage
  |type       = stage
  |stageno    = Second
  |name       = [[Sergeant (rocket)|Sergeant]] cluster
  |engines    = 11 [[solid fuelled rocket|Solid]]
  |solid      = yes
  |thrust     = {{convert|7480|kgf|lbf kN|abbr=on|order=flip}}
  |SI         = {{cvt|214|isp}}
  |burntime   = 6 s
  }}
  {{Infobox rocket/stage
  |type       = stage
  |stageno    = Third
  |name       = [[Sergeant (rocket)|Sergeant]] cluster
  |engines    = 3 [[solid fuelled rocket|Solid]]
  |solid      = yes
  |thrust     = {{convert|2040|kgf|lbf kN|abbr=on}}
  |SI         = {{cvt|214|isp}}
  |burntime   = 6 s
  }}
}}

The '''Jupiter-C''' was an American research and development vehicle<ref>{{cite web |url=https://history.redstone.army.mil/ihist-1957.html |title=Redstone Arsenal Historical Information – 1957 |publisher=United States Army |access-date=2015-05-15 |archive-date=2015-05-18 |archive-url=https://web.archive.org/web/20150518095241/http://history.redstone.army.mil/ihist-1957.html |url-status=live }}</ref><ref>{{cite web |url=https://history.redstone.army.mil/space-jupiter.html |title=Redstone Arsenal Historical Information – Jupiter |publisher=United States Army |access-date=2015-05-15 |archive-date=2015-05-18 |archive-url=https://web.archive.org/web/20150518095238/http://history.redstone.army.mil/space-jupiter.html |url-status=live }}</ref> developed from the [[Jupiter-A]].<ref>{{Cite web|url=http://www.spaceline.org/rocketsum/jupiter-c.html|title=Rockets and Missiles|website=SpaceLine.org|access-date=2018-04-19}}</ref> Jupiter-C was used for three [[Uncrewed vehicle|uncrewed]] [[sub-orbital spaceflight]]s in 1956 and 1957 to test [[Re-entry vehicle|re-entry nosecones]] that were later to be deployed on the more advanced [[PGM-19 Jupiter]] mobile missile. The recovered nosecone was displayed in the Oval Office as part of President Dwight D. Eisenhower's televised speech on November 7, 1957.<ref>Yanek Mieczkowski, 'Cheerleader in Chief, in Eisenhower’s Sputnik Moment: The Race for Space and World Prestige, pp. 105–106.</ref>

A member of the [[Redstone (rocket family)|Redstone rocket family]], Jupiter-C was designed by the U.S. [[Army Ballistic Missile Agency]] (ABMA), under the direction of [[Wernher von Braun]].<ref name="expinfo">
{{cite web |url=https://history.nasa.gov/sputnik/expinfo.html |title=Jupiter-C Explorer-I |publisher=NASA}}</ref> Three Jupiter-C flights were made. These were followed by satellite launches with the vehicle designated as Juno I  (see [[Jupiter-C#Juno I|Juno I]] below or the [[Juno I]] article).<ref>{{cite web |url=https://history.redstone.army.mil/space-redstone.html |title=Redstone Arsenal Historical Information – Redstone Rocket |publisher=United States Army |access-date=2015-05-15 |archive-date=2015-05-18 |archive-url=https://web.archive.org/web/20150518095236/http://history.redstone.army.mil/space-redstone.html |url-status=live }}</ref><ref>{{cite web |url=https://history.redstone.army.mil/space-explorer.html |title=Redstone Arsenal Historical Information – Explorer I |publisher=United States Army |access-date=2015-05-15 |archive-date=2015-07-03 |archive-url=https://web.archive.org/web/20150703022718/http://history.redstone.army.mil/space-explorer.html |url-status=live }}</ref> All were launched from [[Cape Canaveral Air Force Station|Cape Canaveral, Florida]].

== Description ==
Each vehicle consisted of a modified [[PGM-11 Redstone|Redstone ballistic missile]] with two solid-propellant upper stages. The tanks of the Redstone were lengthened by 8&nbsp;ft (2.4 m) to provide additional propellant. The instrument compartment was also smaller and lighter than the Redstone's. The second and third stages were clustered in a "tub" atop the vehicle.
[[File:Redstone-jupiterc-mercuryredstone-compared.jpg|thumb|left|upright|[[Redstone (rocket)|Redstone]], '''Jupiter-C''' and [[Mercury-Redstone Launch Vehicle|Mercury-Redstone]] rockets compared]]
[[File:Juno upper stages.jpg|thumb|left|upright|Second stage cluster]]

The second stage was an outer ring of eleven scaled-down [[MGM-29 Sergeant|Sergeant]] rocket engines; the third stage was a cluster of three scaled-down Sergeant rockets grouped within. These were held in position by bulkheads and rings and surrounded by a cylindrical outer shell. The webbed base plate of the shell rested on a [[bearing (mechanical)|ball bearing]] shaft mounted on the first-stage instrument section. Two electric motors spun in the tub at a rate varying from 450 to 750 rpm to compensate for thrust imbalance when the clustered motors fired. The rate of spin was varied by a programmer so that it did not couple with the changing resonance frequency of the first stage during flight.<ref>{{cite web|url=http://www.designation-systems.net/dusrm/app4/juno.html |title=ABMA Juno I |publisher=Designation-systems.net |access-date=2013-03-25}}</ref>

The upper-stage tub was visibly spun-up before launch. During first-stage flight, the vehicle was guided by a gyro-controlled autopilot controlling both air-vanes and jet vanes on the first stage by means of servos. Following a vertical launch from a simple steel table, the vehicle was programmed so that it was traveling at an angle of 40 degrees from the horizontal at burnout of the first stage, which occurred 157 seconds after launch.<ref>Juno V Space Vehicle Development Program Report No. DSP-TM-10-58, NASA, October, 1958.</ref>

At first-stage burnout, [[explosive bolt]]s fired and springs separated the instrument section from the first-stage tankage. The instrument section and the spinning tub were slowly tipped to a horizontal position by means of four air jets located at the base of the instrument section. When the apex of the vertical flight occurred after a coasting flight of about 247 seconds, a radio signal from the ground ignited the eleven-rocket cluster of the second stage, separating the tub from the instrument section. The third stage then fired to raise the [[apogee]]. Through this system, designed by [[Wernher von Braun]] in 1956 for his proposed [[Project Orbiter]], the Jupiter-C obviated the need for a guidance system in the upper stages.<ref>Juno V Space Vehicle Development Program Status Report, DSP-TM-11-58, NASA, November, 1958.</ref>

===Juno I===
{{Main|Juno I}}
The [[Juno I]] was a satellite launch vehicle based on the Jupiter-C, but with the addition of a fourth stage, atop the "tub" of the third stage and the use of Hydyne as fuel. The Juno name derived from Von Braun wishing to make the satellite launch appear as peaceable as the [[Vanguard rocket]], which was not a weapon, but was developed from a weather study rocket, the [[Viking rocket|Viking]]. Since the Juno I was the same height as the Jupiter-C (21.2 meters), with the added fourth stage being hidden inside the shell, this vehicle which successfully launched the first orbital satellite of the United States is often incorrectly referred to as a Jupiter-C.

==Encrypted serial number==
The Jupiter-C was part of the [[Intermediate-range ballistic missile|IRBM]] project, and the sequence of manufacture of the rockets (which are not necessarily launched in order, and may be uprated as solutions to technical problems are worked out in tests) was considered a military secret. So the designation painted on the sides of the rocket was not a serial number in [[clear text]], but employed a simple transformation cypher that the staff would be sure not to forget. The key was taken from the name of the design and test base: [[Huntsville, Alabama]], giving HUNTSVILE, with duplicated letters dropped: H was used for 1, U for 2, ..., E for 9 and X for 0. For example, the Jupiter-C / Juno I modified to launch [[Explorer 1]] had "UE" painted on the side, indicating it was S/N 29 (U→2, E→9).<ref>{{Cite web|url=http://www.spaceline.org/rocketsum/jupiter-c.html|title=Rockets and Missiles / Jupiter C Fact Sheet|website=www.spaceline.org|access-date=2018-04-19}}</ref><ref>{{Cite web|url=https://history.nasa.gov/SP-4402/ch1.htm|title=SP-4402 Origins of NASA Names|website=history.nasa.gov|access-date=2018-12-26}}</ref>

== General characteristics ==
* Weight as configured for [[Explorer 1]] launch, loaded/empty
**    Overall, takeoff: 64,000&nbsp;lb (29,000&nbsp;kg)/10,230&nbsp;lb (4640&nbsp;kg)
**    Stage 1 62,700&nbsp;lb (28,400&nbsp;kg)/9,600&nbsp;lb (4,400&nbsp;kg)
**    Stage 2 1,020&nbsp;lb (460&nbsp;kg)/490&nbsp;lb (220&nbsp;kg)
**    Stage 3 280&nbsp;lb (130&nbsp;kg)/140&nbsp;lb (64&nbsp;kg)
* Propulsion
** Stage 1: [[Rocketdyne]] A-7 engine
*** Thrust, 83,000&nbsp;lbf (370&nbsp;kN)
*** burning time, 155 s
*** specific impulse, 235 s (2.30&nbsp;kN·s/kg)
*** propellants, liquid oxygen, as oxidizer, and alcohol as fuel
*** propellant feed, turbopump type
*** turbopump drive, 90% hydrogen peroxide decomposed by catalyst bed to produce steam
** Stage 2: Eleven [[Jet Propulsion Laboratory|JPL]] scaled-down [[MGM-29 Sergeant|Baby Sergeant]] rockets
*** Thrust, 16,500&nbsp;lbf (73&nbsp;kN)
*** burning time, 6.5 s
*** specific impulse, 220 s (2.16&nbsp;kN·s/kg)
*** propellant, polysulfide-aluminum and ammonium perchlorate ([[solid propellant]])
** Stage 3: Three JPL scaled-down [[MGM-29 Sergeant|Baby Sergeant]] rockets
*** Thrust, 4,500&nbsp;lbf (24&nbsp;kN)
*** burning time, 6.5 s
*** specific impulse, 235 s (2.30&nbsp;kN·s/kg)
*** propellant, same as for Stage 2

== Flight history ==
* '''September 20, 1956''': Jupiter-C RS-27, lifted an 86.5-lb (39.2&nbsp;kg) payload (including a 30-lb (14&nbsp;kg) dummy [[satellite]]) to an altitude of 680&nbsp;mi (1,100&nbsp;km), a speed of 16,000&nbsp;mph (7&nbsp;km/s), and a range of 3,300&nbsp;mi (5,300&nbsp;km) from [[Cape Canaveral Air Force Station|Cape Canaveral]], Florida.<ref name="expinfo"/><ref name="skyrocket">{{Cite web |title=Jupiter-C |url=https://space.skyrocket.de/doc_lau_det/jupiter-c.htm |access-date=2023-10-14 |website=Gunter's Space Page |language=en}}</ref>
* '''May 15, 1957''': Jupiter-C RS-34, lifted a 300&nbsp;lb (140&nbsp;kg) scale Jupiter ablative nose cone to an altitude of 350&nbsp;mi (560&nbsp;km) and a range of 710&nbsp;mi (1,100&nbsp;km).<ref name="expinfo"/><ref name="skyrocket" />
* '''August 8, 1957''': Jupiter-C RS-40, lifted a 1/3-scale Jupiter nose cone to an altitude of 285&nbsp;mi (460&nbsp;km) and a range of 1,330&nbsp;mi (2,140&nbsp;km); Juno I (four-stage configuration).<ref name="expinfo"/><ref name="skyrocket" />

== References ==
{{Reflist|45em}}

{{Expendable launch systems}}




[[Category:1956 in spaceflight]]
[[Category:Sounding rockets of the United States]]
[[Category:Space launch vehicles of the United States]]