Loopy Laythe

[ejhawman]

Lately I have been working on Laythe ascent vehicles. They tend to require more bulk than I expected, due to a strange effect: losing thrust at certain altitudes and/or speeds.

This happens with aerospikes, LV-T30s, even Skippers. I get to around 15-20k, thrust at max all the way, and without having to touch the keyboard the thrust meter suddenly dives, fluctuates, sometimes cuts out entirely. This tends to make ascent from Laythe partly an endurance run, so I need much more fuel than I should.

I've seen this lifting off from Kerbin with a few vehicles as well, but much more rarely.

Has anyone else had this happen? Is this a known issue not mentioned on the wiki? What could be going on here?

[HoloYolo]

Screenshot? Mods? It would be better if you showed us how and when so we can help you fix it.

[Bzz]

Post some pictures/videos about Your vehicles, because it's hard to understand what is wrong with them.

Maybe this video to Laythe will answer any of Your questions be giving You any ideas how to change Your vehicles or inspire You to make new one.

Edited July 14, 2015 by Bzz

[Anglave]

I've run a Laythe land and return mission in 1.0.4 Stock. I found ~3400 ÃŽâ€v (atmospheric) to be an acceptable (minimum) number for reaching orbit from the ground. Realistically you probably want a bit more. In this regard, the Wiki is incorrect, the 2800m/s number it lists will absolutely strand you.

I did find that the atmosphere's density seemed to decrease slower than I would have expected as I ascended, but I didn't find any strange dead spots or places where my thrust suddenly cut out.

Are you sure you're not losing fuel flow to an engine or something? Are you using any mods?

[Red Iron Crown]

Almost surely the effect of a mod, this is not stock behavior. The usual suspect is MechJeb with either "Limit to Terminal Velocity", "Prevent Overheats", or "Limit Acceleration to X m/s" enabled (these features work even if not using autopilot).

If you're not using MechJeb, can you list your mods and perhaps show a screenshot of the craft?

Also, moving this to Gameplay Questions.