Talk:Saturn IB

Engine info

Does anyone think there's any point to having information about the H-1 and J-2 engines on this page when it's basically a duplicate of part of the H-1 and J-2 pages? Mark Grant 20:19, 21 July 2006 (UTC)

Since no-one seems to care, I've removed those sections. We should really expand the rest to be more like the Saturn V article. Mark Grant 23:30, 29 July 2006 (UTC)

Payload to LEO

I am missing something?? The article states that the IB could lift 15,300 kg (33,700 lb)into LEO. However according to the Apollo Command/Service Module page the CSM weighed 30,332 kg (66,871 lb). One of these figures must be wrong as the Saturn IB lifted an Apollo CSM into LEO on five different manned missions. Prehaps the author of the article got pounds and kilograms mixed up and the LEO-payload of the Saturn IB is actually 33,700 kg? Teiresias84 04:17, 22 May 2007 (UTC)

I'm guessing that on low earth orbit flights the Apollo Service module was loaded with much less fuel than for the Lunar missions, accounting for the difference in masses. -- Beb. —Preceding unsigned comment added by 69.222.11.226 (talk) 14:28, 10 September 2007 (UTC)

I have been equally frustrated in receiving what I consider should be expert answers about this question of LEO payload. I posed this question originally to the editor of Astronautix.com about three years ago when I noticed a mismatch between Saturn 1B LEO capability and Apollo Spacecraft Gross Weight. Even if you look at the published value of Dry Weight... the 14,000 kg figure looks irritatingly close to the maximum LEO listed in the adjoining panel of about 15,000 kg. The answer given by the editor of Astronautix.com referred to downloading propellants as well and searching through his site I believe I found a reference to some hardware being omitted from Service Modules destined for Saturn 1B launches - however no specific mention is given of hardware changes in any Saturn 1B documentation. This problem is vexing to me because I feel the lack of credible data plays into the people who claim the whole moon landing was a hoax. We are supposed to be technically accurate people when we present these articles. Leaving such a glaring error only adds to the impression that Wikipedia cannot be trusted. Voradtralundir (talk) 17:30, 20 October 2009 (UTC)

I've fixed this. See Apollo Command/Service Module where I've added a Service Module subsection which explains the smaller SPS propellant load. 15,300 kg is indeed too small; it lifted the heaviest CSM which was Skylab 4 (20,800 kg.) I don't know where you got 14,000 kg "published Dry Weight" from; check your math. The dry weight components listed on the CSM page (Structure, Electrical system and SPS engine) total only 6,110 kg. Adding the CM gives 11,919 kg. so there is plenty of headroom for a partial propellant load. JustinTime55 (talk) 18:15, 5 February 2010 (UTC)

I might be wrong but I think you are not looking at this problem correctly. On a Saturn V moon mission the service module would be a part of the payload, but on a S 1b orbital mission the SM can be viewed as a third stage/payload combination. All the first two stages have to do is get the CM & SM into a state where the service module engine can raise and circularize the orbit. The point is that the SM is not dead weight and it increases the payload to LEO mass for the Saturn 1b on the missions that it was flown on. I am not sure what the maximum weight of the CM/SM was, but it had to be much more than the LEO capacity of the S 1b rocket. I think that the SM has to be viewed as a third stage on the missions it was used. —Preceding unsigned comment added by Corumplex (talk • contribs) 19:50, 5 June 2010 (UTC)

On further review I checked the mission plan for Apollo 7 and they not only orbited the CM/SM but also the S IVb stage at an altitude of 123 x 153 NM which they used as a target for approach and docking tests. From that adds about 11,000 Kg without any help from the SM. That would make ~27,000kg to orbit. It would seem that 20,800 kg to LEO was a very different figure from total mass to LEO which ignored the fact that the whole second stage orbited in a flight plan with a 16,520 kg cm/sm as payload. I suspect that the payload to LEO was simply based on the heaviest CM/SM launched (Skylab 4). Who knows what they could have done using SM as stage 3?Corumplex (talk) 21:03, 5 June 2010 (UTC)

Yes, you are quite wrong and changing the article would be completely out of order: it's called original research which is frowned on here. You have several fallacious points:

• The empty S-IVB (third stage) is reckoned as the spent launch vehicle's dead weight, not payload, even if they used it for rendezvous practice. The definition of "payload" as universally understood assumes you're going to throw the empty tanks away.
• There was one time when it flew without any spacecraft (CSM or LM), on AS-203. The article quotes an "apogee mass" which includes the complete S-IVB, but the payload was actually the unburned hydrogen fuel inside the tank (it was deliberately short-loaded some oxygen so only the hydrogen would be left), plus some sensors and cameras to observe its behavior. That exact number is harder to pin down.
• The Service Module is part of the spacecraft (payload) and is not a third stage.
• This rocket is history, and not made since the 1970's. There is no competition to see how high the payload number can go (the Space Race ended in 1975!) Speculation about what they might have done with it is just that: speculation, and moot.

The classical number quoted by NASA has always been on the order of 30-some thousand pounds, but the weights of Apollo 1 and the Skylab flights were closer to 45,000-46,000 lb, so that has to be the most sensible number to quote (in the absence of a definitive number from NASA.) It's also possible they made modifications to upgrade the capability of the later ones, as they did for the Saturn V. JustinTime55 (talk) 15:15, 8 June 2010 (UTC)

No, it is not "original research" to point out that the stated numbers just don't add up. If I went out and established new figures that would be original research. Everything I quoted was already published.

The published figures at the very best are a 'nominal' figure which doesn't represent the true capabilities of the vehicle. Records of the flights make this obvious. It's like me claiming that because my car has never been driven faster than 75 MPH that my car has a top speed of 75 MPH. The correct conclusion would be that the car has a top speed of 'at least 75 MPH'.

The empty S-IVB (second stage)was used as a part of the mission as a docking and rendezvous target and therefore it was a necessary and required piece of equipment for the on orbit part of the flight and was, therefore 'payload'. Mission profile determines what is payload.

If you don't like this then look up the Sputnik. It's final stage was counted as part of it's mass. The question about what has been counted as payload on space missions is not so simple.

Well, Justin as you point out the whole point is moot but if someone, for some idiotic reason was concerned with how much mass a Saturn 1b could put into orbit he would not be well served by reading this article. At the very least there should be a notation that that the figures are 'nominal' and theoretical maximum LEO payload was never published and statistics from flights indicate it would be greater than 46,000 lbs. Corumplex (talk) 17:07, 9 October 2010 (UTC)

Responsees in-stream:

"No, it is not "original research" to point out that the stated numbers just don't add up. If I went out and established new figures that would be original research. Everything I quoted was already published."

What I meant by original research, was coming up with novel methods to define payload capability, such as using the Service Module as a third stage, which was never done (or even contemplated.)

"The published figures at the very best are a 'nominal' figure which doesn't represent the true capabilities of the vehicle. Records of the flights make this obvious. ..."

This is a non-sequiter; "nominal" is used by NASA to mean average or expected. To which published figures are you referring? The Wikipedia article quotes 46,000 lb because that is the payload given for the heaviest craft launched, Skylab 4. That is a true figure (they weighed the spacecraft on every flight), not a "nominal" one.

"... It's like me claiming that because my car has never been driven faster than 75 MPH that my car has a top speed of 75 MPH. The correct conclusion would be that the car has a top speed of 'at least 75 MPH'."

Fair enough; still, if the manufacturer hasn't told you what the top speed is, you have no basis for speculating any figure in excess of 75 MPH. Similarly, the Saturn IB has lifted as much as 46,000 lb; however adding the words "at least" isn't verifiable at this point (unless someone is able to find out from NASA.)

"The empty S-IVB (second stage)was used as a part of the mission as a docking and rendezvous target and therefore it was a necessary and required piece of equipment for the on orbit part of the flight and was, therefore 'payload'. Mission profile determines what is payload."

This is an unsupportable argument. The rendezvous practice was not a critical objective of the mission, whose purpose was to verify the CSM systems, including life support and the Service Module engine. And even if it were, a launch vehicle doesn't know or care for what purpose its parts are being used, therefore that can't affect its capablity. Gemini 4 was the first flight to do the very same thing with its spent Titan II second stage (a little-known fact, probably because of the spacewalk.) That doesn't increase the Titan capability.

"If you don't like this then look up the Sputnik. It's[sic] final stage was counted as part of it's[sic] mass. The question about what has been counted as payload on space missions is not so simple."

Yes, it is; that's an extremely poor example. It's the kind of subterfuge that was typical of the Soviet government during the Cold War, when a major objective of their space program was to frighten the West with their missile throw weight capability. One could arbitrarily increase the payload capability of every single launch vehicle in the world by adding its last stage dead weight; it proves nothing. That's not what the spaceflight community has chosen to do; check the definitions given in wikt:payload (number 3) and Payload (air and space craft). You can't give a rocket credit for launching part of itself. (Remember, these still aren't true spaceships, with the exception of the Space Shuttle.)

"Well, Justin as you point out the whole point is moot but if someone, for some idiotic reason was concerned with how much mass a Saturn 1b could put into orbit he would not be well served by reading this article. At the very least there should be a notation that that the figures are 'nominal' and theoretical maximum LEO payload was never published and statistics from flights indicate it would be greater than 46,000 lbs. [emphasis added]"

Statistics from exactly which flights indicate that? Again, 46,000 was the heaviest one launched. That is actual weight of that craft, not "nominal".

Therefore, there is nothing wrong with the article's current listing of 46,000 lb., until such time as anyone can verify anything different. JustinTime55 (talk) 21:35, 13 October 2010 (UTC)

Justin- Would I be well served if I were planning a mission using the S-IVb as a station after the fuel/lox has been purged and re-pressurized with a breathable environment? When they did Skylab they considered this as an option. There have been such plans proposed using both the spent tanks of the S-IVb and the shuttle. According to your thinking S-IVb can't be orbital payload therefore it's use in orbit is not possible. The truth is that it was used in orbit as a docking target. One of the main reasons heaver S-1b flights were not made was they had the S-V for all the really heavy work. It is dishonest to say that the heaviest payload they did fly is the heaviest payload they COULD fly. Therefore it is more accurate to say "At least 46,000 lbs" rather than maximum of 46,000 lbs. Some guy with a slide rule figured it out once, for several mission profiles, but who knows if it was ever published? My interest in this is to speculate what might have been done with the S-1b if it had not been scrapped so quickly in favor of the shuttle program. Since there was never a mission flown to test the full capabilities of the S-1b just saying max payload 46,000 lbs is far from accurate.Corumplex (talk) 04:56, 1 February 2016 (UTC)

WP:Drop the stick and back slowly away from the horse carcass. We're well aware of the original wet workshop plan for Skylab, which proves nothing, and doesn't change the original research theory of counting the empty upper stage weight as "payload", regardless of how it's used. (Also: NASA was never publicly specific about exactly how they would have built the wet workshop; the initial launch would have either carried part of the required equipment (probably a smart thing to do), or else it would have had some hydrogen and oxygen left over to be dumped (like on AS-203).) The clearly accepted definition of payload for an expendable launcher is how heavy a spacecraft you can put in orbit after throwing the spent stage away. No one is being dishonest; there might have been a margin above 46,000 lbs, but we don't seem to be able to find a reliable source saying exactly what that was, so it would be dishonest to speculate (you do not know the figure was any larger than 46,000.) The [Saturn Project Fact Sheet] published in August 1965 gave the estimated payload (before the fact) of only 36,000 lbs, and Mark Wade's article gives only 41,000 lb. And a Google search on "saturn ib payload capacity" gives our article as the first answer based on the 46,000 in our infobox. Wikipedia would be better served if you could worry about finding an up-to-date RS. JustinTime55 (talk) 22:18, 1 February 2016 (UTC)

BTW, Telecineguy (talk · contribs) has found an external source which quotes the 46,000 lb figure, and linked it in the infobox on December 22. Thanks much. JustinTime55 (talk) 17:07, 4 February 2016 (UTC)

• You are welcomed, worked at JPL for a few years, funnest job ever. Still love the subject. Telecine Guy 05:55, 18 February 2016 (UTC)

Engine thrusts

• Question: The first stage (S-IB) section quotes first stage thrust as 1,600,000 lb, which contradicts the 1,500,000 lb (classical number) given in the infobox. Does anyone know the source/accuracy of the higher number? Is this an indication that they did, indeed uprate this vehicle? Or is it a mistake? Obviously the article shouldn't contradict itself.
• The second stage S-IVB single J-2 engine thrust was quoted as 200,000 lb, which I believe was the classical number when it was first designed. But the Saturn V (S-IVB-500) thrust is 225,000 lb (which again might have included an upgrade uprate) and I can find no indication the S-IVB-200 was different from the -500, so I updated this number. JustinTime55 (talk) 13:06, 9 June 2010 (UTC)

I've found the answer to the above question myself by looking at the H-1 (and J-2) engine articles. Apparently the 1,500,000 lb was a mistake; divided by 8 gives 187,500 lb per engine, and it was never that low. It started at 200,000 lb and stayed there until the Skylab missions, when it was uprated to 205,000.

Similarly, the J-2 started at 200,000 lb for only the first three unmanned missions, then was uprated to 225,000 lb for the Apollo missions (1, 5 and 7) and the first two Skylabs. Then it was uprated again to 230,000 lb for the last three vehicles (of which only two flew.)

This might explain an increase in payload capability over time. JustinTime55 (talk) 19:42, 9 June 2010 (UTC)

English vs. Metric units

It doesn't matter that more people understand metric units, if the vehicle was originally designed in English units. When the original source is in English (a United States vehicle designed in the 1960's when the US public was not familiar with metric units), policy on historical subjects says that should be the primary to reduce the chance of unrecognized conversion errors. There happens to be a serious conversion error in the table, which proves this point: the Instrument Unit was not 9.1 metres (30 ft) tall (!), it was only 3.0 feet (0.91 m) tall.

The statement on the Human Spaceflight page recommending metric-only is IMO misguided and warrants discussion. It conflicts with the general WP policy to include both units (regardless of which is primary) so that no one is disenfranchised. Whether you like it or not, most people in the US are not familiar enough with metric to do the conversion in their heads. Back in the late 1970's our government misguidedly tried to "encourage" the conversion on us, with no success. Today we buy soda by the liter; that's about it.

If you want to keep metric primary (esp. in the Infobox, if consistency among articles is a requirement) that's one thing, but deletion of the English is not warranted.

What does everyone else think? JustinTime55 (talk) 16:15, 16 June 2010 (UTC)

You will find that most 1960s Apollo NASA press kits contained metric units of measurement. The original article was written with metric, and most spaceflight articles are now in metric on Wikipedia. It's the world standard, that even NASA uses today. However, if it is accurately converted, and you will find in many Wikipedia articles dealing with spacecraft do contain both, usually the metric is primary and then Imperial Units (again this gets confusing because it depends on either using English or American gallons, which is one of many units that differ in Imperial Units). Metric is less confusing overall, but as long as the converted units are using the right kind of gallon, for instance, then add it in. Wikipedia does have an automated subroutine for this. Abebenjoe (talk) 00:10, 17 June 2010 (UTC)

Thank you for the response. I still think it would have been better to improve the update by putting the metric units first, rather than simply reverting it. In doing so, you deleted several number corrections, including takeoff thrust. With your kind permission, I will re-insert the English units after the metric. And it would be less confusing to measure fuel metrically by the liter rather than cubic meter (or Imperial gallons), wouldn't it? Do you buy gas by the liter, or by the Imperial gallon? JustinTime55 (talk) 15:43, 17 June 2010 (UTC)

I buy natural gas for my house by the cubic metre, and when I'm not bicycling, I buy gasoline for a car by the litre. If it's in a gaseous state, it's measured by the cubic metre, if it is a liquid, it's by the litre. Also, I do believe the Instrument Unit is three metres not three feet: I've seen it at the Kennedy Space Center and the Washington Air and Space Museum, and it was taller than a human. I'll check my Saturn 1b manual tomorrow and confirm this. When adding non-metric units, please make sure the conversion is accurate.--Abebenjoe (talk) 05:57, 18 June 2010 (UTC)

I just looked up the measurements for the third block IU and indeed all third block IUs had a height of 36 inches (3 feet) or 911 millimetres (0.91 metres). The diameter is the same on all three blocks at 266 inches (22.17 feet), or 6,756 millimetres (6.76 metres). All AS200 series flights flew with the third block IU. For a reference, see Saturn V News Reference (Changed) December 1968. I remember it being bigger, but that simply might be extra panelling that attaches the IU to the S-IVb or simply I didn't judge the height correctly. Either way, the definitive measure is from the NASA handout, 36 inches.--Abebenjoe (talk) 06:27, 18 June 2010 (UTC)

Sanity check on parameters

• Here's a tip: specific impulse = (thrust x burn time) / propellant mass (assuming the burn rate is constant, which is nearly true for this rocket. Thrust, and therefore specific impulse, change with altitude (air pressure) for the first stage.) The first stage value had to be incorrect, though the second stage value was good.
• If "finspan" is analagous to the wingspan of a plane, it includes the total width from wing tip to wing tip, so includes the fuselage width. Therefore finspan must be measured from one fin tip to the opposing one, including the stage diameter. JustinTime55 (talk) 16:47, 21 March 2011 (UTC)

Manned vs. Crewed

This article does not conform to Wikipedia Style Guide on use of gender neutral language: https://wiki.riteme.site/wiki/Wikipedia:Manual_of_Style#Gender-neutral_language

The references to "manned" and "unmmaned" should be changed to "crewed" and "uncrewed" to follow current practices on technical language. I have attempted edits but they have been labeled as "disruptive" and edits have been reverted. Please justify those reversions in light of the violations to the style guide. — Preceding unsigned comment added by CooNeo (talk • contribs) 05:14, 12 February 2016 (UTC)

Only if it can be "done with clarity and precision". In this case, it's neither clear nor precise. You're making up your own terms instead of using clearly established ones. - BilCat (talk) 05:55, 12 February 2016 (UTC)

"Crewed" means spacecraft/mission had human crews, and "uncrewed" means that it had no crew, so the description is clear and precise -- please point to a specific ambiguity if you still find this confusing. This is the current state of practice in describing NASA space missions. Please see NASA Style Guide http://history.nasa.gov/printFriendly/styleguide.html and examples like http://appel.nasa.gov/2014/10/30/an-uncrewed-mission-designed-to-advance-human-space-exploration/ -- I am most definitely not making up any new term, and I believe that this article must conform to inclusive language use. CooNeo (talk) 16:52, 12 February 2016 (UTC)

If this article were about a current space vehicle, I might agree with you. But we should avoid the fallacy of WP:presentism: judging historical events by current standards. The terms "manned" and "unmanned" were in use when this historical, now obsolete program (Saturn/Apollo) was conducted. No one is being excluded by using those terms here. "Gender-neutral language does not inherently convey a particular viewpoint, political agenda or ideal;" I believe you are pushing a particular agenda by insisting that "manned" and "unmanned" is not "inclusive language use" when applied to 1960s spacecraft. JustinTime55 (talk) 19:55, 12 February 2016 (UTC)

Thank you for the thoughtful comment. I have thought about whether this is an example of presentism (or worse, revisionism). I do not think rewording "manned" with "crewed" is presentism because I am not placing judgment. I also extended my thought on whether this is revisionism -- it would be if I were to, say, refuse to refer to the Johnson Space Center's former name, Manned Spacecraft Center, but we are just dealing with the choice of adjectives here. I believe that what we are dealing with here is an evolution of English language, and I still believe that phasing out "manned" and rewording with "crewed" is appropriate. This is definitely not one of the exceptions discussed in WP:GNL. I think we all share an agenda to write articles in a relevant manner to present-day audience -- avoiding gendered language is an evolution of the language, and (though I'm fairly new at WP editing) it seems to be a movement recognized at Wikipedia. By the way, I would like to target https://wiki.riteme.site/wiki/Lyndon_B._Johnson_Space_Center next since that article deals with current matters and still refers to things by "manned" -- but I see that you edit that article a lot so I don't really want to open up another thread unless you think it's appropriate. CooNeo (talk) 18:48, 15 February 2016 (UTC)

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Height?

Hello everybody.

In every other language version of wikipedia I checked they tell me that the height of the Saturn IB was 68 m, only the English page says it's 43.2 m? A factsheet I found states 224 ft which is about 68 m too. The reference in the article leads to a "page not found". Every image showing a size comparison between Saturn IB and Saturn V shows clearly that the IB is more that half the size of the Saturn V (110.6 m). So what? 82.220.81.242 (talk) 09:52, 3 March 2023 (UTC)

You can read, I presume? It says "without payload". The Saturn IB was launched in three separate configurations; the most common one (with an Apollo CSM spacecraft) stood a total of 224 feet. However, it launched once with only the Apollo LM spacecraft inside the Spacecraft LM Adapter and a nose cone on top, and once with no spacecraft at all, just a nose cone. JustinTime55 (talk) 20:42, 3 March 2023 (UTC)