Talk:RD-107

Number of combustion chambers

The article mentions that there are 4 combustion chambers but the image and images of the R-7 both show there being 6 combustion chambers - 4 large and 2 small - rather than just 4. As basic physics alone hints with regard to efficiency, the smaller 2 combustion chambers likely are less efficient and thus have a different role than merely providing lift(maneuvering or something else)but they are clearly still part of the main engine and appear to also share the same turbo pump and fuel connection.

1) What are their roles?
2) Can the article be a little clearer on the number of combustion chambers?
3) Why do these smaller combustion chambers exist on this rocket and not others? Were they rendered obsolete? Was there another way of doing the same thing? Are they better or worse? Is there a tradeoff that's known to rocket scientists but not mentioned in the article?

Thanks
67.7.200.239 (talk) 00:20, 10 July 2015 (UTC)

Like you suggested, there role is for rocket guiding, a so called Vernier thruster (making sure the rocket goes in the right direction). They can rotate in one axis.

Soyuz (rocket)

The RD-107 engine is fixed (bolted) to the rocket frame and can not pivot like a RD-180 see here.

It makes sense that they also contribute a "little" to the actual thrust but like said they are used for guiding the rocket, the article could be clearer on this so do your thing :). --Felipe (talk) 10:40, 10 July 2015 (UTC)

Yes, those are vernier thrust chambers. I'm away from my computer but will do a general re-write about this and more next week. It should be merged with the RD-108 and explained a lot more. Those two are the most from rockets in history (along with RD-253).Baldusi (talk) 04:37, 12 July 2015 (UTC)

I've made a bunch of additions to this engines. It launched the first satellite and the first human to orbit, so it should be an important engine. Now that we have a better base, I guess people can still make small additions. But this should be an A quality article. Baldusi (talk) 17:19, 15 July 2015 (UTC)

Merger proposal

I propose that the RD-117 article be merged into this article, since the RD-117 is a slight variation of the RD-107, and the latter article already explains the former, even with more detail than the specific RD-117 article. Baldusi (talk) 19:41, 3 September 2015 (UTC)

Support. All for consolidation of these pages where appropriate, it helps make engine families more clear and reduces confusion. A(Ch) 12:46, 4 September 2015 (UTC)

RD-117

Why is it still in production after Soyuz U is retired? — Preceding unsigned comment added by 188.105.76.82 (talk) 17:18, 25 May 2017 (UTC)