Talk:Comparison of orbital rocket engines

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Citations and sources are needed

Please be sure that the many assertions made in this new article are verifiable. Especially any new items added to the article should have inline citations for each claim made. As a courtesy to the editor who has put a lot of work into this article to date, and who is in the middle of getting it in good order right now, a couple of the existing unsourced claims have been tagged ^{{{citation needed}}} to allow some time for sources to be added. But the entire article will need to be sourced. Cheers. N2e (talk) 16:00, 23 December 2011 (UTC)[reply]

Great job Savemaxim, for getting those few requested items sourced so quickly. I have an idea for the citation metadata that I find makes it easier when reusing refs, and also a slight change for adding the citation info in Wikipedia edit mode, as it makes it easier to separate the article claims from the citation, in subsequent edits. If you're interested, ask. But what you've done is fine, and definitely meets the essentials of WP:V. N2e (talk) 21:49, 23 December 2011 (UTC)[reply]

Missing engines, could someone include them?

The LR-87 and especially the most powerful liquid Hydrogen fuelled engine, the M-1 (rocket engine), need to be included in the table. I am not tech savvy so don't know how to include both in the table. help is required. — Preceding unsigned comment added by 86.45.64.216 (talk) 11:48, 27 January 2012 (UTC)[reply]

Any design on paper could be considered "the most powerful". The M-1 only got to component level testing... and since it hasn't been funded in over 40 years, i don't think i can be considered "in development". Look at page 11: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19680006392_1968006392.pdf — Preceding unsigned comment added by Auroranaut (talk • contribs) 03:27, 10 February 2012 (UTC)[reply]

The RD-270 engine is missing. It's mentioned on Wikipedia in its own article as retired, development stopped during testing. Can it be added?Avmich (talk) 02:40, 7 April 2014 (UTC)[reply]

LE-7A rocket engine is where?

Hello, I seem to be there is not any descriptions of the LE-7A rocket engine on the table. There is missing rocket engine LE-7A on Japanese H-2A/B launch vehicle , where is? Could you someone tell me why? Is there any reasons? thanks.--純之助 (talk) 02:25, 29 February 2012 (UTC)[reply]

Don't be so pushy :). Added. Savemaxim (talk) 12:43, 29 February 2012 (UTC)[reply]

Savemaxim, not sure I see how anything that the editor who asked the question did was being pushy. Please assume good faith, and let's not bite the newcomers. Cheers. N2e (talk) 22:35, 29 February 2012 (UTC)[reply]

Yeah, sorry, pushy was a wrong word here, I just tried to look funny. Cannot understand how it comes that people find time to write comments but have no time (or afraid of) to edit article themselves. Cheers. Savemaxim (talk) 09:36, 1 March 2012 (UTC)[reply]

Savemaxim, thank you to write the article of LE-7A. N2e, I don't care of it, thank you. The reason why I do not edit this article belongs to my poorly English skills. Maybe, I loook like so funny in 'Engrish' from you...--純之助 (talk) 14:23, 1 March 2012 (UTC)[reply]

Formatting

The entire table is in italics for no discernable reason. If italics have a purpose here their use should be made clear and consistent. 24.58.54.118 (talk) 20:10, 25 June 2012 (UTC)[reply]

Thrusts

This might be just me being thick. Some figures for the "vacuum thrust" column were calculated by including Earth's surface G. Isn't that used for sea-level thrust? Marasmusine (talk) 08:02, 2 May 2013 (UTC) Worse, it seems that the thrusts given are for multiple engines in a stage not single ones. Yet another example of needing to take Wikipedia with a grain of salt. — Preceding unsigned comment added by 67.87.243.175 (talk) 19:33, 17 September 2013 (UTC)[reply]

When a thrust is given in pounds force, or kilograms force, there is an implicit factor of the earth's surface gravity in the value. The thrusts in the table are given in Newtons. Hence any factors in the calculation are to remove the implicit earth's acceleration that occurs in the other units from the value in Newtons. The values in the table appear to be correct, and are given for a single engine. Multiple engines may be used on a stage, but the thrust values in the table are for a single engine. For the thrust to weight ratio, the weight is mass times earth's acceleration. Therefore when the mass is given in kilograms, it needs to be multiplied by earth's gravity to get the weight in Newtons. --66.41.154.0 (talk) 20:21, 26 September 2013 (UTC)[reply]

Thrust-to-weight ratio

Some of the entries for the TTW ratios aren't cited directly, but calculated based on other parameters. However, there ought to be a clarification as to what thrust figure is actually taken into account for the TTW ratios that are cited directly from references (and not calculated on the article page): Sea-level thrust? Vacuum thrust?

Similarly, the TTW of an upper stage engine might use a weight-at-altitude; although I don't think this is the case. — Preceding unsigned comment added by 123.237.156.169 (talk) 17:16, 22 January 2014 (UTC)[reply]

The claim "This page exposes the full list of orbital rocket engines."

This is obviously not true (and the missing engines are numerous: from old ones, through the Chinese, to the most recent developments like in Europe).

Should it read "this page aims to expose a full list"? aegis maelstrom δ 16:28, 23 January 2014 (UTC)[reply]

I changed to 'This page exposes the list of orbital rocket engines (list is not full!).' Savemaxim (talk) 11:11, 30 January 2014 (UTC)[reply]

Thrust-to-weight ratio of Merlin 1D

Still do not have an official source saying that Merlin 1D has a 150 TTW ratio. Smb, please add.Savemaxim (talk) 11:18, 30 January 2014 (UTC)[reply]

False alarm. Found a source. Savemaxim (talk) 11:31, 30 January 2014 (UTC)[reply]

Some new information on merlin 1d

https://www.quora.com/Is-SpaceXs-Merlin-1Ds-thrust-to-weight-ratio-of-150+-believable

Merlin 1D (current) TWR is 157.7, not 150 as listed. Weight is 1030lb / 467kg

I suggest we change the entry. Also, have in mind that the listed iSP is from the Merlin 1D vac, which is a different engine (different nozzle, optimized for 2nd stage use only). I think it needs a second entry really, especially since both engines are updated right now and will fly on this November on SES-9.

The TWR will go up to 180+ then. For reference, the new merlin 1D vac full thrust is rated for 934kN / 210.000lbf , and has an ISP of 348s The new merlin 1D full thrust is rated for 756kN / 170.000lbf (SL) and 825kN / 185.500lbf (vac). According to Tom Mueller on quora, it seems like the weight will remain the same.

source: http://www.spacex.com/falcon9

85.72.73.49 (talk) 11:22, 21 September 2015 (UTC)[reply]