Restructure. Improve node execution precision by an order of magnitude.

boot/default.ks

@@ -1,6 +1,8 @@
+@LAZYGLOBAL OFF.
+
 CLEARSCREEN.
 print "=================== BOOTING ===================".
-wait until SHIP:UNPACKED.
+wait until SHIP:LOADED and SHIP:UNPACKED.
 
 if HOMECONNECTION:ISCONNECTED {
     update_scripts().

launch.ks

@@ -1,6 +1,11 @@
-run once util.
+@LAZYGLOBAL OFF.
-run once vectors.
+
-run once node.
+run once "lib/equations".
+run once "lib/node".
+run once "lib/rocket".
+run once "lib/util".
+run once "lib/vectors".
+run once "lib/warp".
 
 
 function launch {
@@ -52,11 +57,8 @@ function launch {
     
     // LAUNCH
         
-    // Can't use flameout or MAXTHRUSTAT on the initial staging, since the rocket may be held down by a launch tower
+    // Enable auto-staging
-    until STAGE:SOLIDFUEL + STAGE:LIQUIDFUEL <> 0 stage_when_ready().
+    when should_stage() then {
-    
-    // Auto-stage when any of the engines flameout or if there are no active engines (e.g. when we have an intermediate stage for decouplers before activating the next engine)
-    when any_flameout() or SHIP:MAXTHRUSTAT(0) = 0 then {
         stage_when_ready().
         return true.  // preserve trigger
     }
@@ -83,9 +85,7 @@ function launch {
     
     print "--- CIRCULARIZE ---".
     print "Waiting for ship to leave the atmosphere..".
-    set KUNIVERSE:TIMEWARP:RATE to 4.
     wait until SHIP:DYNAMICPRESSURE = 0.  // don't create maneuver node until we are out of the atmosphere - otherwise the apoapsis altitude and eta will change due to drag
-    KUNIVERSE:TIMEWARP:CANCELWARP().
     
     print "Deploying solar panels".
     PANELS ON.

lib/equations.ks

@@ -0,0 +1,10 @@
+@LAZYGLOBAL OFF.
+
+function orbital_velocity {
+    // Calculate the required velocity to acheive orbit at the provided altitude.
+    // https://en.wikipedia.org/wiki/Orbital_speed#Mean_orbital_speed
+    // http://www.orbiterwiki.org/wiki/Front_Cover_Equations
+    parameter altitude.
+    
+    return SQRT(BODY:MU / (BODY:RADIUS + altitude)).  // BODY:MU = CONSTANT:G * BODY:MASS
+}

lib/node.ks

@@ -1,10 +1,16 @@
-run once util.
+@LAZYGLOBAL OFF.
+
+run once "lib/rocket".
+run once "lib/warp".
 
 
 function estimated_burn_duration {
-    // Calculate estimated burn duration for a maneuver node
+    //
+    // Calculate estimated burn duration for a maneuver node.
+    // Based on:
     //  https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation
     //  https://space.stackexchange.com/questions/27375/how-do-i-calculate-a-rockets-burn-time-from-required-velocity
+    //
     parameter node is NEXTNODE.
     
     local exhaust_velocity is isp_sum() * (CONSTANT:G * KERBIN:MASS).
@@ -13,8 +19,10 @@ function estimated_burn_duration {
 
 
 function execute_node {
+    //
+    // Execute given maneuver node (the next one by default).
+    //
     parameter node is NEXTNODE.
-    parameter precision is 0.05.  // m/s delta-v
     
     local burn_duration is estimated_burn_duration(node).
     
@@ -24,14 +32,12 @@ function execute_node {
     print "Aligning ship with burn vector..".
     SAS OFF.
     lock STEERING to node:DELTAV.
-    wait until VANG(SHIP:FACING:VECTOR, node:DELTAV) < 0.1.
+    wait until VANG(SHIP:FACING:VECTOR, node:DELTAV) < 0.5.
     
     print "Initializing warp".
-    unlock_control().
     warp_for(MAX(0, node:ETA - (burn_duration/2) - 5)).  // warp until 5s before node
     
     print "Approaching".
-    lock STEERING to node:DELTAV.
     wait until node:ETA <= CEILING(burn_duration/2).  // CEILING instead of ROUND, since we'd rather start the burn too soon to have time for perfecting the burn
     
     print "Burn!".
@@ -41,7 +47,12 @@ function execute_node {
     wait until estimated_burn_duration(node) <= 1.
     lock THROTTLE to MAX(0.01, estimated_burn_duration(node)).  // ensure we always finish by burning with at least 1% power
     
-    wait until node:DELTAV:MAG < precision.
+    // The burn vector will start to drift once we have very little left to burn. Therefore, take a "snapshot" of the burn vector as it is right now, and lock steering to it, instead of the dynamic vector
+    local dv0 is node:DELTAV.
+    lock STEERING to dv0.
+    
+    // Stop the burn once the "snapshot" vector dv0 and current burn vector start facing opposite directions
+    wait until VDOT(dv0, node:DELTAV) < 0.
     set THROTTLE to 0.0.
     
     print "=== MANEUVER NODE EXECUTED ===".

lib/rocket.ks

@@ -0,0 +1,62 @@
+@LAZYGLOBAL OFF.
+
+function any_flameout {
+    //
+    // Return true if any of our engines are starved for fuel. Primarily used to determine the need for staging.
+    //
+    local engines_list is list().
+    list ENGINES in engines_list.
+    for engine in engines_list {
+        if engine:IGNITION and engine:FLAMEOUT {
+            return true.
+        }
+    }
+    return false.
+}
+
+
+function should_stage {
+    //
+    // Return true if the rocket needs to stage.
+    //
+    return SHIP:STATUS = "PRELAUNCH"  // e.g. still attached to launch tower
+        or any_flameout()             // any engine starved for fuel
+        or SHIP:MAXTHRUSTAT(0) = 0.   // no active engines (e.g. when we have an intermediate stage for decouplers before activating the next engine)
+}
+
+
+function stage_when_ready {
+    //
+    // Stage when ready. Blocks until staging has been initiated.
+    //
+    wait until STAGE:READY.
+    print "STAGING".
+    STAGE.
+}
+
+
+function isp_sum {
+    //
+    // Return the sum of vacuum ISP for enabled engines.
+    //
+    local sum is 0.
+    local engines_list is list().
+    list ENGINES in engines_list.
+    for engine in engines_list {
+        if engine:IGNITION {
+            set sum to sum + engine:VACUUMISP.
+        }
+    }
+    return sum.
+}
+
+
+function unlock_control {
+    //
+    // Ensure that the throttle is 0 and that the player is not locked out of control.
+    //
+    set SHIP:CONTROL:PILOTMAINTHROTTLE to 0.
+    set SHIP:CONTROL:NEUTRALIZE to true.
+    unlock STEERING.
+    unlock THROTTLE.
+}

lib/util.ks

@@ -0,0 +1,8 @@
+@LAZYGLOBAL OFF.
+
+function round_towards_zero {
+    parameter n.
+    
+    if n < 0 return CEILING(n).
+    return FLOOR(n).
+}

lib/vectors.ks

@@ -1,3 +1,5 @@
+@LAZYGLOBAL OFF.
+
 // Define actual_prograde, which automatically switches from SHIP:SRFPROGRADE to SHIP:PROGRADE
 local function set_actual_prograde {
     if NAVMODE = "SURFACE" {

lib/warp.ks

@@ -0,0 +1,13 @@
+@LAZYGLOBAL OFF.
+
+function warp_to {
+    parameter timestamp.
+    
+    KUNIVERSE:TIMEWARP:WARPTO(timestamp).  // TODO: improve.
+    wait until TIME:SECONDS >= timestamp. // TODO
+}
+
+function warp_for {
+    parameter seconds.
+    return warp_to(TIME:SECONDS + seconds).
+}

util.ks

@@ -1,79 +0,0 @@
-function warp_to {
-    parameter timestamp.
-    
-    KUNIVERSE:TIMEWARP:WARPTO(timestamp).  // TODO: improve.
-    // wait until TIME >= timestamp. // TODO
-}
-
-function warp_for {
-    parameter seconds.
-    return warp_to(TIME:SECONDS + seconds).
-}
-
-
-function stage_when_ready {
-    wait until STAGE:READY.
-    print "STAGING".
-    STAGE.
-}
-
-
-function isp_sum {
-    local sum is 0.
-    list ENGINES in engines_list.
-    for engine in engines_list {
-        if engine:STAGE = STAGE:NUMBER set sum to sum + engine:VACUUMISP.
-    }
-    return sum.
-}
-
-
-function any_flameout {
-    list ENGINES in engines_list.
-    for engine in engines_list {
-        if engine:FLAMEOUT return true.
-    }
-    return false.
-}
-
-
-function round_towards_zero {
-    parameter n.
-    
-    if n < 0 return CEILING(n).
-    return FLOOR(n).
-}
-
-
-function orbital_velocity {
-    // Calculate the required velocity to acheive orbit at the provided altitude.
-    // https://en.wikipedia.org/wiki/Orbital_speed#Mean_orbital_speed
-    // http://www.orbiterwiki.org/wiki/Front_Cover_Equations
-    parameter altitude.
-    
-    return SQRT(BODY:MU / (BODY:RADIUS + altitude)).  // BODY:MU = CONSTANT:G * BODY:MASS
-}
-
-
-
-function unlock_control {
-    // Ensure that the throttle will be 0 when execution stops
-    set SHIP:CONTROL:PILOTMAINTHROTTLE to 0.
-    
-    // Ensure that the player is not locked out of control.
-    set SHIP:CONTROL:NEUTRALIZE to true.
-    unlock STEERING.
-    unlock THROTTLE.
-}
-
-
-function disable_engine_gimbal {
-    // Disable engine gimbal when engine is off
-    on (THROTTLE = 0) {
-        list ENGINES in engines_list.
-        for engine in engines_list {
-            if engine:HASGIMBAL set engine:GIMBAL:LOCK to (not THROTTLE).
-        }
-        return true.  // preserve trigger
-    }
-}

various.ks

@@ -0,0 +1,14 @@
+@LAZYGLOBAL OFF.
+
+function disable_engine_gimbal {
+    //
+    // Disable engine gimbal when engine is off.
+    //
+    on (THROTTLE = 0) {
+        list ENGINES in engines_list.
+        for engine in engines_list {
+            if engine:HASGIMBAL set engine:GIMBAL:LOCK to (not THROTTLE).
+        }
+        return true.  // preserve trigger
+    }
+}