In your case you certainly scored on atmosphere, non-equatorial orbit and other mods. other mods (warranty void if used with other mods ).non-equatorial target orbit (MJ have problems with inclinations).non-equatorial launch site (requires thrust offset, which screws with delta-v).high thrust ratio (creates wobbling and reduces accuracy of burns).lagging game (bad and weird things can happen).rockets that require RCS to fly straight (fixing bad design with corrective steering is still a bad design ).wobbling rockets (they tend to fall apart).weird rocket with weird, unpredictable, drag (MJ likes straight, pointy and rigid rockets).atmosphere (drag and aerodynamic forces).'Manual' inclination fix and circularization burns, remember to leave some time between maneuversĪs for difference in AP and PE, there is plenty of things that will make ascent less accurate Disable corrective steering - however without solid rocket you are very likely to perform rapid lithobraking without this option.Skip Circularization in ascent guidance and replace it with Change Inclination and Circularize maneuvers.Ordering MJ to change inclination once in orbit.Launching to inclination if 86 degrees, which will result in (almost) polar orbit (dirty hack, but it works).Note: issue occurs both in 1.0.5 and 1.1 version. Gravity turn gets skewed by Corrective Steering when fighting planet rotation and Circularization plainly ignores inclination. Circularization (burn until designated PE is reached).Coasting to edge of atmosphere (only when necessary).Gravity turn (burn until designated AP is reached).Vertical ascent (first few seconds of launch).And use orbital data readouts from MJ or KER instead of eyeballing it )

TLDR: Launch to inclination of 86, then do some fine-tuning once in orbit. MJ ascent guidance Corrective Steering overcompensates for planet rotation, which visibly skews ascent to highly inclined orbits. The orbit is like 5º offset and the apoapsis and periapsis is not 100k, is 110k and 90k respectively (approximately) I'm trying to orbit Kerbin at 100km with 90º of orbit inclination using mechjeb ascend guidance but mechjeb is not making vessel orbit correctly.

Ksp mac not launching