Talk:Jupiter-C

Unreliable data

I've been trying to track down good numbers for the various rocket parameters. Mass fractions, Isp, that sort of thing. This Jupiter-C Wiki page is an example of the problem. For example, the Isp's listed in the infobox don't match the text. This is the data needed to cross check and back engineer the orbital calculations. Rectified (talk) 04:44, 22 December 2016 (UTC)

Notes from old Wiki edits and Talk page

Interesting details

The upper-stage tub was spun-up before launch. During first-stage flight, the vehicle was guided by a gyro-controleld 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 travelling at an angle of 40 degrees from the horizontal at burnout of the first stage, which occurred 157 seconds after launch. At first-stage burnout, explosive bolts 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 and fourth stages were fired in turn to boost the satellite and fourth stage to an orbital velocity of 18,000 mph (8 km/s).

Note- It's stupid to leave the spinning tub attached to the 2nd stage, and to leave all that attached to the 3rd+ stage. Maybe the tub was actually released before 2nd stage ignition, and the third stage rose up out of the ring of 2nd-stage motors, but the wording doesn't reflect this. Rectified (talk) 03:39, 19 December 2016 (UTC) 

Note- This staging protocol does not use an optimal trajectory from the surface to orbit, which varies for each rocket and launch. It's inefficient, but it's simple, cheap and effective. The cost is a tiny payload. It looks like they burnout at 60 miles, 155 sec, 40 degrees from horizontal (slightly below parabolic optimum for range on a flat Earth, so they are going for some horizontal velocity), then coast up to a 'parabolic' apogee, which will become the perigee of the final orbit. For the Explorer 1 launch, what is the design attitude at 1st stage apogee? It would be (?) more ideal to tilt it to the local velocity vector of the design orbit, with an apogee of 1500 km, not 2550 km. Sounds like they just went with a horizontal attitude at whatever altitude, which is much easier to do: no real-time computation required. The 2nd stage solids were lit "by hand", by a man on the ground with a stopwatch and some mojo intuition. Then the rest of the final orbit parameters are determined by the vagaries of the three stages of solid rocket burns, so things like the inclination deviations would be expected. Rectified (talk) 03:39, 19 December 2016 (UTC) 

This method of orbiting a payload obviated the need for a guidance system in the upper stages, and was invented by Wernher von Braun in 1956 for his proposed Project Orbiter, which would have been just like the Jupiter-C but using the even smaller solid-fuel upper stages which were the only ones available at that time. His method was the simplest and most immediate method for putting a payload into orbit, but as it had no upper-stage guidance, it was not put into a precisely specified orbit. - Revision as of 16:34, 22 December 2004

Jupiter C was renamed Juno I when modified as a satellite launch vehicle to meet the Eisenhower administration desire that a non-military vehicle be used to launch the first American satellite. (See: McDougal, Walter A. the heavens and the Earth a Political History of the Space Age, 1985 Basic Books NY ISBN 0-465-02887-Xpg 123) The Army considered the "Juno !" as a Jupiter C. (See http://history.redstone.army.mil/ihist-1958.html)

As for the renaming of the Jupiter C the credit for coming up with the name Juno goes to Dr. William Pickering. "On November 18, 1957 Dr. William Pickering, head of the Jet Propulsion Laboratory, suggested to Medaris that the satellite-bearing version of the Jupiter C be renamed Juno." See: http://spaceline.org/rocketsum/jupiter-c.html Today not even NASA adheres to the fiction that Americas first satellite was launched by a "civilian" rocket. See: http://history.nasa.gov/sputnik/expinfo.html

Pulled from the Wiki Talk page:

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POV?

"Calling a Redstone-based rocket a Jupiter to show that something was getting done for the money paid for the Jupiter project is typical of the changes-of-name that take place in military industries." I'm not so sure about this... it seems a little POV'd, and not really on target for the Jupiter-C rocket article. If there's no response, I'll go ahead and delete.Sjcodysseus 05:16, 6 December 2005 (UTC)

Contradiction

The date of the maiden flight in the table differs from that in the main article.

RE: The date in the maiden table refers to the first orbital flight, which isn't clearly labeled. Also, the burnout time listed in the table (120 s) refers to the burnout time of the original Redstone without the increased tankage. It's not clear which of the two figures given in the text (155 s and 157 s) is correct, but I can say that 155 seconds is the amount of time the Rocketdyne engine would take to burn all of the fuel at 100% throttle.

The following discussion is an archived debate of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the debate was PAGE MOVED per discussion below. -GTBacchus^(talk) 11:37, 17 September 2006 (UTC)

Requested move

[[Jupiter-C (rocket)]] → Jupiter-C – Unnecisarry Disambiguation GW_Simulations_{User Page | Talk} 16:27, 10 September 2006 (UTC)

Survey

Add "* Support" or "* Oppose" followed by an optional one-sentence explanation, then sign your opinion with ~~~~

• Support per nom and other recent rocket articles. David Kernow 01:43, 11 September 2006 (UTC)

Discussion

Add any additional comments

The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Cleanup and split

The following discussion is an archived debate of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the discussion was to split.--GW_Simulations_{User Page | Talk} 23:30, 22 September 2006 (UTC)

This article seems to conflate the Jupiter IRBM, the Jupiter-C sounding rocket, and the Juno I launch vehicle:

The Jupiter was an IRBM, and the Jupiter-C was not so the lead is clearly incorrect.

The Jupiter-C was a 3-stage sounding rocket, which was used to test re-entry vehicles.

The 4-stage launch vehicle described in much of the article is the Juno I, which was used to orbit satellites, including Explorer 1. It is commonly confused with the Jupiter-C because the only real difference is the presence of the upper stage. Even some official sources get this wrong from time to time.

Therefore, I propose that this article is cleaned up, and information on the Juno is split out to a seperate article. I would be happy to do this if consensus (or lack of objection) is reached. --GW_Simulations_{User Page | Talk} 13:16, 17 September 2006 (UTC)

Sounds like a good idea, GW.Fl295 16:44, 17 September 2006 (UTC)

It's been more than 5 days, no objections, so I am carrying out the split. --GW_Simulations_{User Page | Talk} 23:30, 22 September 2006 (UTC)

The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Confusion between Juno I and Jupiter-C

Confusion remains, both Juno I and Jupiter-C pages claims they launched Explorer 1 - phe 23:57, 13 November 2006 (UTC)

Jupiter C was NOT a sounding rocket Mark Lincoln (talk) 16:56, 14 May 2015 (UTC)

Jupiter C, like the Jupiter A which preceded, it was NOT a Sounding rocket. It was a research and development vehicle. This clearly stated in two Redstone Arsenal histories. "1 March 57 The first JUPITER R&D missile was fired, but the flight was unsuccessful."and "5 May 57 JUPITER C Missile RS-34 was fired to test thermal behavior of a scaled-down version of the JUPITER nose cone during reentry. The nose cone was not recovered; however, instrument contact with the cone through reentry indicated that the ablative-type heat protection for warheads was successful." See http://history.redstone.army.mil/ihist-1957.html

There is alsoclear mention of the purpose of the Jupiter C in the Redstone Arsenal history of the Jupiter program "In the beginning, a 50-missile test program was planned involving a composite of JUPITER C’s for re-entry vehicle tests, JUPITER A’s for component testing, and the JUPITER configured missile." and "The actual flight testing in support of JUPITER development was divided into three phases. Two of these used the REDSTONE as the flight test vehicle to prove out JUPITER components. Designated as JUPITER A’s, 25 missiles were fired between September 1955 and June 1958. Objectives of these tests were to obtain design criteria, apply the angle-of-attack meter to the IRBM, evolve separation procedures, prove guidance system accuracy, and design and prove propulsion system thrust control. To solve the re-entry problem, three missiles designated as JUPITER C’s were flown. As to the tally, 20 of the 25 JUPITER A’s were rated as mission achieved, two registered partial successes, and three were considered to be unsuccessful." See http://history.redstone.army.mil/space-jupiter.html

Jupiter C was renamed Juno I when modified as a satellite launch vehicle to meet the Eisenhower administration desire that a non-military vehicle be used to launch the first American satellite. (See: McDougal, Walter A. the heavens and the Earth a Political History of the Space Age, 1985 Basic Books NY ISBN 0-465-02887-Xpg 123) The Army considered the "Juno !" as a Jupiter C. (See http://history.redstone.army.mil/ihist-1958.html)

Scope of the Jupiter C program

The Jupiter C was created to perform nose cone development for the Jupiter IRBM. "Several of these rockets were assembled, but only three were flown as Jupiter reentry test vehicles (RS-27 on 20 September 1956, RS-34 on 15 May 1957, and RS-40 on 8 August 1957)." " Eighty-four days later, on 31 January 1958, the Army Ballistic Missile Agency launched the first U.S. satellite-Explorer I-into orbit. Following this successful launch, five more of these modified Jupiter-C missiles (subsequently redesignated Juno I) were launched in attempts to place additional Explorer satellites in orbit. Three of these attempts ended in failure. They were: Explorer II, RS-26, on 5 March 1958; Explorer V, RS-47, on 24 August 1958; and Explorer VI, RS-49, on 23 October 1958 The other two successful ones were Explorer III, RS~24, on 26 March 1958 and Explorer IV, RS-44, on 26 July 1958." See: http://history.redstone.army.mil/space-explorer.html

That is there were nine Jupiter C/Juno I launches Mark Lincoln (talk) 18:26, 14 May 2015 (UTC)

As for the renaming of the Jupiter C the credit for coming up with the name Juno goes to Dr. William Pickering. "On November 18, 1957 Dr. William Pickering, head of the Jet Propulsion Laboratory, suggested to Medaris that the satellite-bearing version of the Jupiter C be renamed Juno." See: http://spaceline.org/rocketsum/jupiter-c.html Today not even NASA adheres to the fiction that Americas first satellite was launched by a "civilian" rocket. See: http://history.nasa.gov/sputnik/expinfo.html

The Jupiter C was developed into the Mercury Redstone vehicle See: http://history.msfc.nasa.gov/mercury/msfc_role.html

The name Juno II was used for the Jupiter missile when used to launch space probes See: http://history.msfc.nasa.gov/juno/juno.pdf

Why two changes

First the name of the Jupiter C's engine was 75-110-A-7. "A-7" was just a nickname. http://www.enginehistory.org/Museums/USSRC/USSRC_Redstone.shtml

Most Jupiter C's had four stages. The first three Jupiter Cs were limited to 3 in order to keep the Army from launching a satellite. "For these tests, the Agency used the composite rocket, first proposed for use in Project Orbiter. . . The final stage, intended to orbit a satellite in its former configuration, was replaced by a scaled-down Jupiter nose cone."

Mark Lincoln (talk) 22:08, 29 February 2016 (UTC)