adding stationary orbit helper to Manuever Planner

Localization/en-us.cfg

@@ -198,6 +198,11 @@ Localization
         #MechJeb_match_v_Exception1 = must select a target to match velocities with.
         #MechJeb_match_v_Exception2 = target must be in the same sphere of influence.
 
+        //stationary orbit
+        #MechJeb_stationary_title = stationary orbit
+        #MechJeb_stationary_label1 = Target longitude:
+        #MechJeb_stationary_Exception1 = Stationary orbit around <<1>> is outside SOI.
+
         //resonant orbit
         #MechJeb_resonant_title = resonant orbit
         #MechJeb_resonant_label1 = Change your orbital period to <<1>> of your current orbital period

MechJeb2/Maneuver/OperationStationary.cs

@@ -0,0 +1,100 @@
+extern alias JetBrainsAnnotations;
+using System;
+using System.Collections.Generic;
+using JetBrainsAnnotations::JetBrains.Annotations;
+using KSP.Localization;
+using UnityEngine;
+
+namespace MuMech
+{
+    [UsedImplicitly]
+    public class OperationStationaryOrbit : Operation
+    {
+        [Persistent] public double targetLongitude = 0;
+        [Persistent] public double targetLatitude = 0;
+
+        public override string GetName() => Localizer.Format("#MechJeb_stationary_title"); //stationary orbit
+
+        private void MoveByMeter(ref EditableAngle angle, double distance, double alt, Orbit o)
+        {
+            double angularDelta = distance * UtilMath.Rad2Deg / (alt + o.referenceBody.Radius);
+            angle += angularDelta;
+        }
+
+        public override void DoParametersGUI(Orbit o, double UT, MechJebModuleTargetController targetController)
+        {
+            double asl = o.referenceBody.TerrainAltitude(targetController.targetLatitude, targetController.targetLongitude);
+
+            GUILayout.BeginVertical();
+
+            if (!targetController.PositionTargetExists)
+            {
+                targetController.SetPositionTarget(o.referenceBody, targetLatitude, targetLongitude);
+            }
+
+            GUILayout.Label(Localizer.Format("#MechJeb_stationary_label1")); //Target longitude:
+
+            GUILayout.BeginHorizontal();
+            targetController.targetLongitude.DrawEditGUI(EditableAngle.Direction.EW);
+
+            if (GUILayout.Button("◄"))
+            {
+                MoveByMeter(ref targetController.targetLongitude, -10, asl, o);
+            }
+
+            GUILayout.Label("10m");
+            if (GUILayout.Button("►"))
+            {
+                MoveByMeter(ref targetController.targetLongitude, 10, asl, o);
+            }
+            GUILayout.EndHorizontal();
+
+            if (targetController.targetBody != null)
+            {
+                GUILayout.Label(targetController.targetBody.GetExperimentBiomeSafe(targetController.targetLatitude, targetController.targetLongitude));
+            }
+
+            if (GUILayout.Button(Localizer.Format("#MechJeb_LandingGuidance_button2"))) targetController.PickPositionTargetOnMap(); //Pick target on map
+
+            targetLatitude = 0;
+            targetLongitude = targetController.targetLongitude;
+
+            GUILayout.EndVertical();
+        }
+
+        protected override List<ManeuverParameters> MakeNodesImpl(Orbit o, double ut, MechJebModuleTargetController target)
+        {
+            double syncSMA = Math.Pow(o.referenceBody.gravParameter * Math.Pow(o.referenceBody.rotationPeriod / (2.0 * Math.PI), 2.0), 1.0 / 3.0);
+
+            if (syncSMA > o.referenceBody.sphereOfInfluence)
+            {
+                throw new OperationException(Localizer.Format("#MechJeb_stationary_Exception1", o.referenceBody.displayName.LocalizeRemoveGender()));
+            }
+
+            double currentBodyRotationRad = (o.referenceBody.rotationAngle + (360.0 * (ut / o.referenceBody.rotationPeriod))) * Math.PI / 180.0;
+
+            double targMNA = (targetLongitude * Math.PI / 180.0) + currentBodyRotationRad;
+            targMNA = (targMNA % (2 * Math.PI) + 2 * Math.PI) % (2 * Math.PI);
+            double syncAlt = syncSMA - o.referenceBody.Radius;
+            Vector3d targetWorldPos = o.referenceBody.GetWorldSurfacePosition(0, targetLongitude, syncAlt);
+            Vector3d radiusVector = targetWorldPos - o.referenceBody.position;
+            double velMag = Math.Sqrt(o.referenceBody.gravParameter / syncSMA);
+            Vector3d velDir = Vector3d.Cross(o.referenceBody.angularVelocity, radiusVector).normalized;
+            Vector3d targetVelocity = velDir * velMag;
+
+            Orbit targOrbit = new Orbit();
+            targOrbit.UpdateFromStateVectors(radiusVector, targetVelocity, o.referenceBody, ut);
+            targOrbit.eccentricity = 0;
+            targOrbit.inclination = 0;
+            targOrbit.Init();
+            (Vector3d dV1, double ut1, Vector3d dV2, double ut2) =
+                OrbitalManeuverCalculator.DeltaVAndTimeForHohmannTransfer(o, targOrbit, ut, 0, false, false, true, true);
+
+            return new List<ManeuverParameters>
+            {
+                new ManeuverParameters(dV1, ut1),
+                new ManeuverParameters(dV2, ut2)
+            };
+        }
+    }
+}

MechJeb2/MechJeb2.csproj

@@ -89,6 +89,7 @@
     <Compile Include="Maneuver\OperationPlane.cs" />
     <Compile Include="Maneuver\OperationResonantOrbit.cs" />
     <Compile Include="Maneuver\OperationSemiMajor.cs" />
+    <Compile Include="Maneuver\OperationStationary.cs" />
     <Compile Include="Maneuver\OperationTransfer.cs" />
     <Compile Include="Maneuver\PlotArea.cs" />
     <Compile Include="Maneuver\Porkchop.cs" />