Talk:Rocketdyne F-1

The thrust from a single F-1 is simply amazing
The article states how one F-1 has more thrust that three SSMEs. However, I noticed a while back something else that was stunning. Each F-1 has more thrust than ALL of the rockets and thrusters in a Saturn V/Apollo J combined (aside from the other F-1s). Even if you include all of the ullage thrusters, manuvuering thrusters, Launch Vehicle Escape System thrusters, retro rockets, etc; a single F-1 still has more thrust. That is one strong engine.--Will 04:51, 15 August 2006 (UTC)

Shouldn't the first paragraph read something like '... the most powerful single-nozzle liquid fueled rocket engine ever *flown*'? The M-1 being more powerful but never progressed beyond its development phase. —Preceding unsigned comment added by 92.15.55.55 (talk) 12:19, 29 April 2011 (UTC)

Turbopump performance swimming pool analogy
This is further explanation of my rv of the removal of the "time to fill/drain a swimming pool" as an illustration of F-1 turbopump flow rate. This is a common illustration used in many popular-level sources (including the official Pratt & Whitney / Rocketdyne web site: ) for illustrating the extreme propellant flow rates of large rocket engines. There's nothing "drivel" about it, rather it's an easy-to-understand illustration that's appropriate and approachable for the common readership of a general encyclopedia. The same illustration has been used for decades in various educational books, programs and literature on the space program. Joema 18:59, 17 October 2006 (UTC)


 * First of all, let me apologise for the word "drivel". That was thoughless and inconsiderate.  This comparison however is clearly non-encyclopaedic for the following reasons:
 * It's confusing. One "backyard swimming pool" might be very much different to another (mine is 36,000 litres, less than a 3rd of the 114,000 litre pool that you have).
 * There are very well established SI units, which everyone understands and are unambiguous.  14,000 litres per second cannot be misunderstood, whereas 1 swimming pool per 10 seconds is cumbersome and almost meaningless.  (Why do you think we don't measure things in cubits anymore?)
 * The figures are wrong anyway. 114,000 gallons is more like 513,000 litres.
 * Wikipedia is an encylopaedia, not an advertising forum. It should contain material that informs not words designed to be populist.  Dontdoit 02:06, 18 October 2006 (UTC)


 * Revised swimming pool flow rate analogy slightly. The figures were very accurate. BTW, 114,000 U.S. gallons is 431,537 liters. You can easily do unit conversions directly from the Google query window using the IN keyword. E.g: "7.6 million pounds force IN newtons". It understands many different measurement units.


 * Let me re-emphasize: the swimming pool flow rate illustration is a long standing, historic illustration used in many educational materials over the past 40 years. Here are some examples:


 * * http://www.californiasciencecenter.org/Exhibits/AirAndSpace/HumansInSpace/SaturnVLOXvalve/SaturnVLOXvalve.php
 * * http://science.nasa.gov/headlines/y2002/26sept_goosebumps.htm
 * * http://www.nasa.gov/centers/stennis/pdf/149892main_OASIS%20Spring%202005.pdf
 * * http://www.hq.nasa.gov/office/pao/History/augustine/racfup3.htm
 * * http://marshallstar.msfc.nasa.gov/3-28-02.pdf
 * * http://www.boeing.com/defense-space/space/propul/SSMEamaz.html
 * * http://www-pao.ksc.nasa.gov/kscpao/factoids/funfacts.htm
 * * http://www.space.com/businesstechnology/technology/051019_ipd.html Joema 03:09, 18 October 2006 (UTC)


 * OK, you were talking about US gallons --- as the text didn't specify, I assumed it referred to imperial ones.  If you must include this figure, then please explicitly state US gallons otherwise it's just confusing.  In general I would stick to SI units as they're universal and cause no confusion. You've really missed the point about swimming pools ; simply because a term is in widespread use, doesn't make it encyclopaedic.  This article is a technical one, and should use technical language. Dontdoit


 * OK, specified US gallons. Re swimming pool illustration, I'm afraid you're off-base on that. Make technical articles accessible says writing should "presented in the most widely accessible manner possible". What is a good article? says wording should be: "readily comprehensible to non-specialist readers". Using simplifying illustrations helps achieve that, especially if involving quantities or magnitudes the reader can't easily visualize.


 * The topic may be technical in nature, but Wikipedia style guidelines emphasize making it accessible to the average reader. You likely wouldn't use such an illustration in a narrow-interest, peer-reviewed academic research paper. But Wikipedia is a popular-level encyclopedia. That is exactly why other educational materials about the same topic use similar illustrations. "The History of Manned Space Flight", by David Baker (ISBN: 051754377X) is one of the most encyclopedic, detailed technical histories ever published. Yet even it uses simplifying illustrations about the Saturn V propellant flow rate. In this case it says the SI-C first stage in 2.5 minutes consumes "more propellant that would be consumed by an average motorist in more than 1,000 years of normal driving" (page 294). Joema 19:28, 19 October 2006 (UTC)


 * You're really not being realistic here. Do you really think that there is anyone in the world who can read English to this level, yet does not know what a litre is?  --- or not familiar with decimal counting?  Even if there exists anyone who can only visualise capacities in terms of swimming pools, it would be simple for  this hypothetical individual to refer to swimming pool, to compare his/her standard measure in terms of litres.  We cannot cater for every 1 in a million individual, who has an non-conventional way of measuring fluid capacity --- I mean we'd have to say something like "the F1 engine in 10 seconds, consumes 1 backyard swimming pool, 1/10 of an olympic pool, 1/1000 of a ULCC, 1000,000 chamber pots, 1000,000,000 thimbles" --- it'd be just silly.


 * As you like to refer to WP guidelines, here are some which you really should familiarise yourself with: 1) WP:MOS says: "For units of measure, use SI units as the main units in science articles, unless there are compelling historical or pragmatic reasons not to do so" --- I can't see any compelling reason to express the flow rate of rocket engines in terms of swimming pools --- (note that the editors of swimming pools discuss that subject's size, but don't mention rocket engines even once).  2) Your assumption that all readers of this article have little or no education is a gross violation of WP:CIVIL. 3) Most notably, your point of view just  ignores WP:UCS.  Dontdoit 00:55, 23 October 2006 (UTC)


 * The swimming pool illustration doesn't displace any SI unit measurements in this article -- it's simply an additional illustration to help readers visualize the huge propellant flow rate. This is why so many other educational sources use similar illustrations to help visualize huge magnitudes or quantities. E.g, when discussing the flow rate of Hoover Dam, the PBS Educational Series "Building Big" says Hoover Dam's water flow would fill 15 average-size swimming pools in one second. These are merely illustrations to help the reader visualize the quantities/scales involved.


 * I'm totally stumped by your point #2. Nowhere did I state "all readers of this article have little or no education". Good teaching technique from ancient times has involved use of clarifying illustrations. That's why the swimming pool illustration has been frequently used by other writers, and why even David Baker, Phd (a British technical writer famous for his extreme precision and detail) used the "1,000 year automobile fuel consumption" illustration to help readers visualize Saturn V propellant usage, in his huge encyclopedic History of Manned Space Flight. The swimming pool illustration of propellant flow is appropriate and fitting for an encyclopedia targeted at broad readability. Joema 03:13, 23 October 2006 (UTC)


 * You really don't seem to want to be persauded, so I'm not going to prolong this discussion any further. I just ask you to consider these points:


 * * Does this comparison add anything (information, clarity or readability) to the article?
 * * Other instances of people using journalese doesn't mean that you have to do likewise.
 * * Is it really worth cluttering the article, for the sake of the 1 in 10,000 readers whose normal measure of capactity is swimming pools?
 * --- If after objectively considering these points you still want this comparison, then perhaps you might want to add an entry to the Simple English Wikipedia. But please make this article factual, to the point,  informative and clear. Dontdoit 01:34, 25 October 2006 (UTC)

Just thought I'd weigh in. I think there *is* a historical justification for the use of the swimming pool illustration... namely, that it was a frequently used illustration at the time. If you really want to justify it in the text of the article, you can say something like "Rocketdyne promotional material boasted that the F-1 could empty a swimming pool in (however many) seconds." That contextualises the statement and makes it clear that it's not something that the Wikipedia editor just made up. MLilburne 10:20, 9 November 2006 (UTC)
 * OK, it is a long time but I will write anyway. Yes most people know about a litre, but even so, have a hard time imagining large or small multiples. It would take me some time to image the size of a megalitre or gigalitre, and compare those to a size that I know. Gah4 (talk) 07:46, 6 February 2023 (UTC)
 * OK, it is a long time but I will write anyway. Yes most people know about a litre, but even so, have a hard time imagining large or small multiples. It would take me some time to image the size of a megalitre or gigalitre, and compare those to a size that I know. Gah4 (talk) 07:46, 6 February 2023 (UTC)

Chamber pressure
I just read a journal article by V. Yang that and remember seeing the chamber pressure was 1250 psi. this is much more than the 70 bar listed. —Preceding unsigned comment added by 68.232.118.89 (talk) 03:00, 5 November 2009 (UTC)


 * Has Wikipedia published a Don't Get Wrapped Around The Axle guide? Simple illustrations allow the majority to grasp the incredibly large or incredibly small.  One of the key concepts in teaching is to couch the material in a manner which can be understood by the student.  If Wikipedia serves to educate, the rough order of magnitude comparisons do indeed hold a prominent place.  I've used the following analogy many times to explain Avogadro's Number (6.02*10^23):  That number of green peas would cover the Earth's surface to a depth of 6 inches.  Granted, the comparison is an approximation, but it gives the audience some idea of just how massive Avogadro's Number is, and certainly conveys the magnitude of that figure in a more tangible fashion than simply stating 6.02*10^23.  — Preceding unsigned comment added by 199.64.0.252 (talk) 21:47, 6 September 2011 (UTC)
 * 70 bar is about 1000 PSI, and has about 1 significant figure. 1250 PSI is about 1000 PSI to one significant figure. But even so,it would not be much more than 1000 PSI. Gah4 (talk) 18:51, 30 August 2023 (UTC)
 * 70 bar is about 1000 PSI, and has about 1 significant figure. 1250 PSI is about 1000 PSI to one significant figure. But even so,it would not be much more than 1000 PSI. Gah4 (talk) 18:51, 30 August 2023 (UTC)

Heat resistance
How does this rocket's nozzle and combustion chamber keep from disintegrating under that amount of massive heat and energy? -Rolypolyman (talk) 21:41, 1 March 2008 (UTC)

Regenerative cooling- (User) WolfKeeper (Talk) 02:58, 2 March 2008 (UTC)

Some diagrams
http://history.nasa.gov/ap15fj/01launch_to_earth_orbit.htm

Power in Watts?
As a "finger in the air" comparison of scale to other systems, would anyone care to estimate the power of an F-1 (or a Saturn V at liftoff) in Watts? I'm not confident to do it myself, because I'm aware that it's not a simple unit conversion and simple thrust/power conversions always involve some whopping great assumptions. I guess looking at the PE change on the Apollo stack during launch would be best?

This arose because of a recent deletion at Watt. I'd like to restore this, but really it needs to go back with a footnote of explanation as to how the figure is derived.

Thanks Andy Dingley (talk) 11:35, 5 June 2012 (UTC)


 * "Estimating the power" ourselves would be a clear violation of WP:OR. We would need a cited source. Calculating the "power" of a rocket (or airplane) engine is tricky because of subtleties most laymen don't appreciate. Power by definition is the rate of doing work, which is defined as a force pushing through a distance; therefore propulsive power equals thrust times speed. Since speed constantly changes in flight (and also thrust in the atmosphere), the power isn't constant. And there's even a paradox: at the instant of liftoff, speed is zero; therefore while the engine is producing 1.5 million pounds of thrust, the power is zero!


 * What the layman thinks of as power, would be something more like taking the gasses coming out of the nozzle and driving a turbine with it; how many megawatts of electric power would an attached generator produce? We clearly need a cited source, or else any such number would be meaningless. That's probably why we don't often see it. JustinTime55 (talk) 15:43, 24 September 2013 (UTC)
 * Yes power is complicated, but it isn't that bad. Electrical power plants are commonly rated in both thermal power and electrical power, with the latter about 1/3 of the former, for thermodynamic (Carnot efficiency) reasons. Similarly, one should be able to WP:CALC the thermal power. (I would have to go back to the article to see what it says.) Reminds me, though, some time ago in an airplane museum, an exhibit of a jet engine, with thrust quoted in pounds, and converted to kilograms. I asked, and yes there are official museum guidelines that say pounds and newtons. But then he mentioned that it was different for propeller planes.  It seems that those are rated in HP and kilowatts, and not in pounds or newtons. Gah4 (talk) 19:01, 30 August 2023 (UTC)
 * Yes power is complicated, but it isn't that bad. Electrical power plants are commonly rated in both thermal power and electrical power, with the latter about 1/3 of the former, for thermodynamic (Carnot efficiency) reasons. Similarly, one should be able to WP:CALC the thermal power. (I would have to go back to the article to see what it says.) Reminds me, though, some time ago in an airplane museum, an exhibit of a jet engine, with thrust quoted in pounds, and converted to kilograms. I asked, and yes there are official museum guidelines that say pounds and newtons. But then he mentioned that it was different for propeller planes.  It seems that those are rated in HP and kilowatts, and not in pounds or newtons. Gah4 (talk) 19:01, 30 August 2023 (UTC)

How fast did the engines hit the water?
Brian Walker writes in his CNN blog-article about Jeff Bezos' recovery of an engine, "After doing their work, the rockets plummeted into the ocean at 5,000 miles per hour, where they have been undiscovered for four decades ..." And of course, he gives no citation. The Saturn V page cites the Saturn V flight manual as saying the stage is traveling at 2300 m/s at cutoff, so I thought 5,000 mph might be reasonable (I thought I remembered seeing something like 6,300 mph somewhere) and quoted Walker (maybe he just assumed the in-flight figure held?) An IP user felt this was wrong (so sue me :-) and took a guess and modified it to 500 mph, but we don't have any more verification of that, either.

If you look down in the discussion below Walker's article, a big argument ensues about the true number, not much of it well informed. There's a fallacy in assuming terminal velocity applies; that is for a stationary object that starts free-fall with essentially zero vertical velocity (such as jumping out of a plane.) Comparing it to the "terminal speed of a bullet" is equally fallacious. The stage obviously started its fall with a great deal of speed, and calculating the velocity when hitting the water is only possible if you know its aerodynamic drag characteristic (as well as the weight.) We would have to probably rely on some source e.g. NASA publishing this.JustinTime55 (talk) 19:53, 22 March 2013 (UTC)


 * I've skimmed through a bunch of NASA documents -- e.g. the Saturn V news reference, press kits, and post-mission Saturn V launch reports -- and most of them say roughly where the S-IC would or did hit the sea, but none esimate how fast. Boeing expected to get the impact speed down to around 100 feet per second if they attached parachutes to recover it, but that only sets a lower limit. There's also the question of whether the stage would have hit the sea intact, or broken up in flight; the Boeing recovery plan wanted to use drag flaps at the bottom of the stage to keep it flying nose-first rather than engines-first. With said drag flaps they estimated it would go subsonic at 32,000 feet before the parachutes were opened. Mark Grant (talk) 17:07, 24 March 2013 (UTC)
 * "The stage obviously started its fall with a great deal of speed": yes, but upwards. Then it had to decelerate to vertical velocity zero and then it began to fall down (free fall). But also the horizontal velocity component must be considered. 194.174.76.21 (talk) 17:02, 6 December 2016 (UTC) Marco Pagliero Berlin
 * Thanks, but WP:Wikipedia is not about winning. The point is, absent a reliable source, we're whistling in the dark trying to guess. It's moot because the speed was removed from the article. JustinTime55 (talk) 17:37, 6 December 2016 (UTC)

RD-170?
The RD-170 is mentioned at several inappropriate points in this article, such as the header and in the design section. The placement of these statements suggests that someone feels the characterization of the F1 engine as world's most powerful is not fair. Regardless, this article is about the F1 engine, not the RD-170, so these statements should be removed or moved into a comparison section that stands on it's own. 71.85.231.179 (talk) 07:39, 24 April 2013 (UTC)
 * In particular the claims for the RD-170(171) are doubtfully. When we compare SL with SL then (1 - 6.909/7.257)x100 is only 4.8% and not 20%. Then is the claim doubtful that a cluster is only one engine. The only reason that the Russians use cluster is the never solved the Pogo-instability in a big single combustion chamber feed with a kerosine LOX mixture. --HDP (talk) 12:55, 22 December 2015 (UTC)

Overly long photo caption
IP user 86.46.186.19 added this to the caption of the test firing photo:
 * " In comparison to the hotter and therefore lighter colored inner portion, the darker more fuel rich outer portion of the exhaust gases is clearly visible. This darker region or "curtain" was created by means of the flow of the gas generators exhaust into the turbine exhaust manifold. Serving as a means to cool/protect the nozzle from the intense heat of the lighter colored near stoichiometric combustion products within."

This has several things wrong with it:
 * It is way too long for a picture caption, which should not contain a paragraph. This is the type of thing that should go in the article prose. (Qiestion is, where?)
 * It is possibly too technically complicated for the average reader.
 * It could be construed as trivia; are most readers really interested in what causes this? The exhaust occupies a very small part of the picture, and many may not even see it.
 * It is grammatically defective; "Serving as a means to cool..." is not a complete sentence; it almost looks as if the preceding period should be a comma, but then it becomes a run-on sentence.
 * It is uncited.

There's got to be a better way to present this. JustinTime55 (talk) 20:52, 10 September 2013 (UTC)


 * I put it below the picture as that seemed to be the best place for it, if you disagree I'm sure we can make a place for it beside the picture, or move the picture if need be.
 * It is not too technical, people are well aware of how fuel needs a good source of oxygen to burn efficiently, that's elementary fire triangle stuff friend.
 * Most readers are interested, you should note one such puzzled reader here on this very talk page, under the heading "Heat resistance", enquiring how the engine doesn't just melt under the intense heat.
 * Serving as a means to cool/protect...is me trying to get across what that section of flame does. If you'd like to put a comma or period after the second mention to the "manifold", then go right ahead.
 * It is well cited - (1) It is self evident that darker flame = cooler flame.
 * Not to mention 10 seconds of using my favorite search engine finds: "The interior of the nozzle extension is protected from the engine exhaust gas environment (5800 Fahrenheit) by film cooling, using the turbine exhaust gases ( 1200 Fahrenheit) as the coolant." http://www.apollosaturn.com/s5news/p31-10.htm
 * and - "The effect was to introduce a cooler boundary layer to protect the walls of the thrust chamber extension." http://history.nasa.gov/SP-4206/ch4.htm.
 * and as for my precise wording of "curtain cooling" well this harks back all the way to Robert Goddard who pioneered it. ..."curtain cooling," a method of cooling the inside of the combustion chamber wall of rocket motors." http://airandspace.si.edu/collections/artifact.cfm?id=A19590071000
 * and "Film cooling (aka the cooling curtain) takes place inside the chamber, generally using a ring fuel injector at the periphery of the injector plate, and acts both by cooling the chamber walls by contact and by isolating the walls from the combustion" http://lcas.otaski.org/index.php/RocketEngines


 * Wikipedia...where you can add correct material, but some wiki-kid will not only remove it, but then they'll proceed to create bullet points to try and legitimize their failures while not even doing a quick web search.


 * I've had enough of this place.
 * 86.46.186.19 (talk) 07:55, 11 September 2013 (UTC)

Specific Impulse
The figure at the top of the summary shows the Specific Impulse to be "260 SEC MIN" and "263 MIN". Does that "MIN" stand for "minimum"? 260 sec or 263 sec would make perfect sense. --Armchairastronaut (talk) 11:47, 20 September 2015 (UTC)

Reference number 5 for thrust comparison - and few dates for a timeline
The sentences preceding that reference compare the power output of the F1 to the combined power output of the Space Shuttle engines. The actual reference is strictly about the shuttle engines and makes no reference to the F1 engine, making the comparison dubious.

The other thing I want to mention is although I think this is a well done page it lacks dates and it's hard to put timeline on the things that were being discussed. I can't spend forever reading it but I came here just trying to find when the last time one had actually been fired since Trump has announced but he wants NASA to go back to the Moon. (Allow me one bit of sarcasm? Make the moon great again!) I'm not against the idea, I was against the idea of not finishing the missions they had planned.

But like I said as I look through the article it's hard to draw a timeline on the Development and Construction and use of the engines. Jackhammer111 (talk) 22:38, 12 December 2017 (UTC)

What can we say about the gimballing for thrust vectoring
Angles, rates, actuators ? - Rod57 (talk) 11:30, 5 March 2018 (UTC)

Apparently the 4 outer engines could gimbal enough to cope with an engine out but in none of the actual flights was more than 10% of max angle needed.Quora. Would be nice to add the angles to the Specification section. - Rod57 (talk) 11:16, 13 April 2020 (UTC)

Reusability addition
If this is going to be put in, it needs a lot of work, and attention to some basic Wikipedia policies:
 * WP:Verifiability: WP:Reliable sources need to be cited, to ensure avoidance of WP:Original research.
 * MOS:PERSON Encyclopedic tone forbids the use of first-person chattiness and article referring to itself: "mostlly not known about'; "why this section has so little information"; "Let's imagine for a moment"; "First, let's start with reality".
 * "In an alternate reality": WP:Wikipedia is not a crystal ball; we don't speculate on "alternative realities".

Plus, there are numerous spelling, punctuation, and grammatical errors. JustinTime55 (talk) 19:58, 17 June 2019 (UTC)


 * There was a proposal (from Boeing) to recover the S1-C by parachute, but it was intended that the engines would be replaced, not reused. - Rod57 (talk) 11:19, 13 April 2020 (UTC)

Used baffle
This is a picture of the used F-1 baffle that was on display at the Museum of Flight in Seattle.



Gah4 (talk) 07:57, 6 February 2023 (UTC)

Source of Vacuum Thrust?
I've been trying to cite the info contained in the infobar for a report and I can't actually find 'any' source that corroborates the vacuum thrust figure contained there. I'm not saying it's wrong, but does anyone have any idea where that comes from? – Jadebenn (talk &middot;&#32;contribs &middot;&#32;subpages) 01:20, 20 February 2023 (UTC)

Oklahoma City display
Hello there is a [citation needed] on "An F-1 engine is on a horizontal display stand at Science Museum Oklahoma in Oklahoma City."

I was there last week and it's true, the F-1 is there. What to do in this case? I have a picture. https://www.sciencemuseumok.org/news/moon-landing-anniversary-events-set-science-museum-oklahoma http://heroicrelics.org/omniplex/index.html

2620:149:5:2202:D4EA:892E:25CD:EBE5 (talk) 23:29, 16 April 2024 (UTC)