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MuMech / MechJeb2

MechJeb2 - KSP mod
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#888 Misscalculated circulation orbit using ascent assistant #1850

Open hraban35 opened 6 months ago

hraban35 commented 6 months ago

When launching from Woomera with an inclination of 45° to an orbit at an altitude of 160 km with the ascent assistant and using the classical gravity turn, the flight ends in a total miscalculation to reach a safe periapsis after reaching apoapsis. The orbit circulation calculation does not seem to work correctly.

lamont-granquist commented 6 months ago

Woomerang in stock or Woomera in RSS/RO? Because 'classical' ascents can't handle single burn ascents to orbit automatically and its on you to finesse your way to orbit, you have to use PVG if you're launching off the Earth.

hraban35 commented 6 months ago

In this case, of course, I mean the stock version from KSP. The "Classic Asscent Profile" basically breaks down an ascent into two phases. Phase one is an insertion at the height of the Ap, followed by a second firing phase to raise the Pe. When calculating the second firing phase, a serious error occurs in the calculation which, instead of following the orbital inclination, wants to guide the rocket in a direction I cannot understand. The error only occurs in the tested dev version. As far as I have been able to test, the error only occurs when starting with a significantly higher inclination than 10°. It was most obvious at the described inclination of 52° for launching into the orbit of a space station.