Initial transfer file and some other improvements

scripts/ascent.ks

@@ -92,6 +92,7 @@ function basicAscent {
 
     wait 0.1.
 
+    // this isn't always true, figure out a way around
     panels on.
     radiators on.
     for a in antennas {
@@ -129,7 +130,8 @@ function basicAscent {
   
   // if we're using a booster to get to orbit drop it before finishing the cirularization
   when ship:periapsis > 30000 then {
-    if ship:stagenum <> 0 and ship:stagedeltav(ship:stagenum - 1):current > 0 {
+    // use RCS as a condition to not stage the booster
+    if ship:stagenum <> 0 and ship:stagedeltav(ship:stagenum - 1):current > 0 and not brakes {
       print "Dropping booster".
 
       // shutdown engines before dropping them

scripts/lander.ks

@@ -79,9 +79,11 @@ until h < 1 {
   wait 0.
 }
 
+lock throttle to 0.
+unlock throttle.
 clearscreen.
 print "Holding position".
-lock steering to groundSlope().
+lock steering to lookDirUp(groundSlope(), ship:facing:upvector).
 wait until ship:angularvel:mag < 0.1.
 wait 5.
 print "Stable".

scripts/transfer.ks

@@ -0,0 +1,69 @@
+
+function hohmannDeltaV {
+  parameter r1 is 1, r2 is 1, mu is 1.
+
+  local vCirc to sqrt(mu / r1).
+  local vHohmann to sqrt(mu * (2 / r1 - 2 / (r1 + r2))).
+  return vHohmann - vCirc.
+}
+
+function angleBetween {
+  parameter posA to V(1, 1, 0), posB to V(1, 1, 0).
+
+  local angle to arcTan2(posB:y, posB:x) - arcTan2(posA:y, posA:x).
+  if angle < 0 set angle to angle + 2 * constant:pi.
+  return angle.
+}
+
+
+function hohmannTransfer {
+  // parameter targetPeriapsis is 60000.
+  parameter tgtBody is Mun.
+
+  // get the approximate required deltav for a transfer
+  local r1 to ship:orbit:semimajoraxis.
+  local r2 to tgtBody:orbit:semimajoraxis.
+  local vTransfer to hohmannDeltaV(r1, r2, kerbin:mu).
+
+  // compute the transfer time
+  local transferSMA to (r1 + r2) / 2.
+  local transferPeriod to 2 * constant:pi * sqrt(transferSMA^3 / kerbin:mu).
+  local transitTime to transferPeriod / 2.
+
+  // get lead angle (how far ahead the tgtBody must be)
+  local tgtAV to 2 * constant:pi / tgtBody:orbit:period.
+  local leadAngle to tgtAV * transitTime.
+  local transferAngle to constant:pi - leadAngle.
+
+  // find the next time the phase angle condition is satisfied
+  local shipAV to 2 * constant:pi / ship:orbit:period.
+  local relativeAV to tgtAV - shipAV.
+
+  // get the phase angle to the target
+  local bodyToShip to (ship:position - body:position):normalized.
+  local obtNorm to vCrs(bodyToShip, ship:velocity:orbit:normalized):normalized.
+  local bodyToTgt to vXcl(obtNorm, (tgtBody:position - body:position):normalized):normalized.
+  local signVec to vCrs(obtNorm, bodyToShip):normalized.
+  local phaseSign to vDot(bodyToTgt, signVec).
+  local currentPhaseAngle to vAng(ship:position - body:position, tgtBody:position - body:position) * (constant:pi / 180).
+  if phaseSign < 0 set currentPhaseAngle to -1 * currentPhaseAngle + 2 * constant:pi.
+
+  // get the time to start the maneuver
+  local phaseError is transferAngle - currentPhaseAngle.
+  if phaseError < 0 set phaseError to phaseError + 2 * constant:pi.
+  local waitTime to phaseError / relativeAV.
+  if waitTime < 0 set waitTime to waitTime + ship:orbit:period.
+
+  set nd to node(time:seconds + waitTime, 0, 0, vTransfer).
+  add nd.
+
+  // print "Transfer DeltaV (m/s) : " + round(vTransfer, 2).
+  // print "Transit Time (s)      : " + round(transitTime*57.3, 0).
+  // print "Lead Angle (deg)      : " + round(transferAngle*57.3, 2).
+  // print "Relative AV (deg/s)   : " + relativeAV*57.3.
+  // print "Phase Angle (deg)     : " + round(currentPhaseAngle*57.3, 2).
+  // print "Phase Error (deg)     : " + round(phaseError*57.3, 2).
+  // print "Wait Time (s)         : " + round(waitTime, 0).
+}
+
+hohmannTransfer(Mun).