Talk:Rocket engine

message: : The number of flights and the number of failures is discussed in North American X-15. So, the failure rate would be WP:CALC. Would this be sufficient? It is a minor mention, would it be necessary to copy all the reference from X-15? Another question: are the figures on X-15 cited? It seems that many of these rocketry articles are probably edited by rocket scientists and engineers who cite their brains. Perhaps the OR tag should be a hat. Cheers -Jim — Preceding unsigned comment added by Jim1138 (talk • contribs)  16:24, 27 March 2015 (UTC)
replies: text: I would call it WP:OR. I can't find the word "fail" anywhere in the X-15 article, or any information that would allow calculating a failure rate. (I guess 1 / 199 = 0.5 per cent.) But that statistic is irrelevant here, because the single in-flight failure ("during a ground test" is incorrect) did not have anything to do with the rocket propulsion ("Adams had lost control of the X-15 as a result of a combination of distraction, misinterpretation of his instrumentation display, and possible vertigo.") None of which has any bearing at all on rocket safety. It definitely doesn't belong here, and the standards for rocket failure rate don't seem to be well-defined. JustinTime55 (talk) 21:13, 21 September 2015 (UTC)
replies: text: So you got your lack of knowledge from Wikipedia and then claim somebody else engaged in OR. I'll just leave this here. It's a published video.GliderMaven (talk) 01:42, 23 September 2015 (UTC)
replies: text: If you're so damned smart, why don't you add that incident to the X-15 page, instead of engaging in personal attacks? JustinTime55 (talk) 20:51, 5 January 2017 (UTC)
thread_title: Reliability numbers

message: I just reverted this edit made by 
Several technical and logical problems with this:
*You apparently don't understand what a catalyst is; rocket engines use oxidizers, which are chemically consumed in the reaction, and thus are not "catalysts" which by definition enable a reaction without being consumed. Catalysts are rarely used in rockets.
*A rocket engine does not "carry its own propellant"; liquid propellants are carried in tanks which are not part of the engine. (Note we have a separate article, Rocket, which covers a complete vehicle.) The distinction between engine and propellant is somewhat ambiguous for solid-fuel rockets, where it's not clear whether the "engine" (just a nozzle) actually includes the propellant (i.e., is the casing holding the propellant actually part of the "combustion chamber"?)
*Wikipedia syntax: you broke the citation reference by removing the "<" from the "<ref>" tag. (See WP:Citation templates for guidance.)
*By changing text immediately before the citation reference, you have invalidated what the source (Sutton and Biblarz book) said.
If you feel strongly this change is necessary, please discuss it here first. JustinTime55 (talk) 16:25, 8 November 2016 (UTC)
replies: text: That said though, many rocket engines have used HTP as either a monopropellant or as an oxidiser and these have used catalysts. Many have also used a consumable catalyst: it is easier in engineering terms to supply the catalyst as a fluid in excess and expel it as part of the reaction mass, rather than it is to try and maintain a rocket's high flow rate through a wire mesh or similar. A catalyst used in excess also allows an inefficient catalyst, which may also be far cheaper, compared to a metallic catalyst. Andy Dingley (talk) 16:46, 8 November 2016 (UTC)
thread_title:  Technically inaccurate revision 

message: (This is a continuation of "Reliability numbers" above):
I'm concerned that we're conflating safety considerations of Rocket engines (the topic of this article) with those of Rocket (vehicles); this is complicated by the fact that the two can interact with each other:
* Vehicles can be lost by catastrophic failures of engine components (e.g., a turbopump bearing failure);
* Vehicle failures can be caused by propellant tank, pressurization, or line problems (engine hardware not necessarily involved);
* Vehicle loss can be caused by guidance failures; the vehicle goes off course, not necessarily attributable to engine or airframe failures, but range safety still has to abort the mission and blow up the vehicle.
* Sometimes "engine loss" is caused by no fault of engine hardware, but by problems induced by interactions with the vehicle; e.g. likely culprit is pogo oscillation (see Apollo 6, where the engine's fuel lines were damaged by the oscillation)
* We call the Challenger disaster a "Solid Rocket Booster failure"; sure, the proximate cause was flame burning through the O-rings, but the catastrophic failure was caused by the vehicle turning cross-wise into the wind, exposing it to high aerodynamic stresses, and rupture of the external tank leading to combustion of the propellant.
I think we're oversimplifying just by lumping all failures together correlated to "engine-flights". Any ideas on how to fix this? JustinTime55 (talk) 21:45, 5 January 2017 (UTC)
thread_title:  Safety section 

message: User:JustinTime55 added Template:Infobox machine to the article on September 15, 2020, without any prior discussion. Although I'm generally an advocate of using infoboxes, even for certain types of bio articles where some users oppose them, infoboxes are neither required nor forbidden, but instead subject to article consensus. I believe this article is too general and confusing for an infobox to be of use, as the separate invention dates illustrates. As such, I've removed the infobox per WP:BRD. Please do not restore it without a clear consensus here to do so. Thanks. BilCat (talk) 23:51, 23 September 2020 (UTC)
thread_title:  Infobox 

message: Are there any alternatives? 41.95.23.234 (talk) 16:54, 21 June 2021 (UTC)
thread_title:  Fuel Mixture in Combustion Chamber 

message: Should the Isp section, and especially related to the unit of seconds, explain the connection between mass of propellant and weight (at sea level on earth) of propellant? It is a units trick, convenient in that it gives the same value in different unit systems. Gah4 (talk) 00:34, 15 September 2021 (UTC)
thread_title:  Isp and unit systems 

message: FYI, this article is tagged to use British English, but there are 11 instances of "oxidizer" which should be "oxidiser". JustinTime55 (talk) 15:13, 11 May 2022 (UTC)
thread_title:  Consistent use of Engvar