Fix staging and burn angle.

lib/launch_rocket.ks

@@ -92,8 +92,8 @@ function Launch {
   lock THROTTLE to 0.0.
   set SHIP:CONTROL:PILOTMAINTHROTTLE to 0.
   wait 0.001. // make sure these control updates get applied
-  add CreateCircularizationNode().
-  ExecNode().
+
+  insertionBurn(apoapsisTarget).
 
   print "Ascent Complete.".
   set SHIP:CONTROL:PILOTMAINTHROTTLE to 0.
@@ -101,3 +101,54 @@ function Launch {
   unlock STEERING.
   SAS on.
 }
+
+// Calculate and perform the insertion burn for orbit.
+// The reason to prefer this over CreateCircularizationNode() and ExecNode() is that the amount of RCS needed
+// to vector into position during launch adjusts our orbit significantly. This gives us a "wait until" that
+// serves the specific needs of launch.
+// It also makes automated launches possible before maneuver nodes are unlocked.
+//
+// TODO: Refactor code reuse between this function and ExecNode().
+//
+// prerequisites:
+//   * Vessel is still behind the Apoapsis
+//   * Apoapsis is at the target height
+function insertionBurn {
+  parameter apoapsisTarget.
+
+  // vector is prograde but only on the horizonal plane
+  print "Adjusting heading.".
+  local lock horizon is Vxcl(SHIP:UP:FOREVECTOR, SHIP:PROGRADE:FOREVECTOR).
+  lock STEERING to LookDirUp(horizon, SHIP:FACING:TOPVECTOR).
+
+  // calculate the deltaV to get us to the target velocity, for calculating burn start time.
+  local t is TIME + SHIP:ORBIT:ETA:APOAPSIS.
+  local Vc is sqrt(SHIP:BODY:MU/(PositionAt(SHIP, t) - SHIP:BODY:POSITION):MAG).
+  local dV is Vc - VelocityAt(SHIP, t):ORBIT:MAG.
+
+  if WillStage(dV) {
+    when FlameOut() then {
+      print "Flameout detected. Staging.".
+      stage.
+    }
+  }
+  
+  // calculate the total burn time (Tb) and the burn start time (Ts)
+  local Tb is BurnTime(dV).
+  local Ts is TIME + SHIP:OBT:ETA:APOAPSIS - BurnTime(dV / 2).
+
+  // warp to the burn point
+  print "Waiting for burn window.".
+  wait until (VAng(SHIP:FACING:FOREVECTOR, STEERINGMANAGER:TARGET:FOREVECTOR) <= 0.5) OR (TIME > Ts).
+  if TIME < Ts - 2 {
+    KUNIVERSE:TIMEWARP:WarpTo(Ts:SECONDS - 2).
+  }
+  wait until SHIP:UNPACKED.
+  wait until TIME > Ts.
+
+  // burn until periapsis is clear
+  print "Circularizing orbit.".
+  lock THROTTLE to 1.0.
+  wait until SHIP:OBT:PERIAPSIS > apoapsisTarget.
+  lock THROTTLE to 0.0.
+}