Silpion

Suggestion/request: a procedural engine mount plate. Let us pick how many engines and adjust the radius. For example, I could place five 3.5 meter engines below a large stretchy tank for the Saturn V S-IC and S-II stages, or any other combination of number and radius, like the Falcon 9 v1.1 Octaweb. You could have a couple different parts for the number of rings. For example, to get the 8-engine layout of the Saturn IB S-IB stage.

Big liquid boosters, or the big boosters from KW. I think it's imperfect symmetry in struts causing the boosters to skew as their TWR's get very high toward the end of the burn.

Yeah, but the problem with that is that it requires perfect performance of the spacecraft. Boosters have a habit of causing roll particularly as they run short on fuel, and this triggers a feedback effect with SAS. I think if these shuttle engines are every going to perform like the user expects, the yaw angle must be relative to the engine-COM axis.

Followup: I'm pretty certain now that the yaw is done relative to the spacecraft axis and not the thrust axis, because I made a shuttle which has the engines nearly perfectly aligned with the CoM (I can take my hands off with SAS off and it flies nearly straight), and the yaw command sends it rolling like mad.

Love the new big engine. I'm having an issue with shuttles though: because these engines are well off the side from the center of mass, there is a convolution between yaw and roll: When the engines yaw, the craft both yaws and rolls. This often leads my shuttles to roll out of control, especially late in the ascent, out of the atmosphere. So question: is the axis that the engines do their yaw gimbal relative to along the main thrust axis, or the direction that the craft is pointing? If it is along the thrust axis then this shouldn't be happening (because presumably that axis is through the COM). Suggestions: If it is relative to "forward", is it possible to make it relative to the engine's thrust axis? Separately, can the yaw gimbal range be kept less free than the pitch? Like keep the 10 degree pitch range, but decrease yaw to a more conventional 1 degree? That could slow some of this down.

A thought I had while trying to make my very accurate Apollo modules: A fuel cell part that uses LH2 and LOX.

I was thinking about the NovaPunch 3.5 m 7x 1.25 m adapter, but yeah, it looks like they don't quite fit. 2 meter would be better.

Real sweet. Any chance for a SSME-sized one? 2.5 m, around 2,000 kN?

I was so happy to discover this mod in the Scott Manley video yesterday, so I went all-out with the Modular tanks mod and did a to-scale Apollo mission. Imgur album and Reddit thread. Thanks for all your work! Other than some difficult-to describe instability, the only bug I want to point out is the Mun seeming to have some kind of height layer that hovers some 10's of km above the real ground. It was weird to pass through that on my way into the landing.