finalized raden launch

wip landing script

library/lib_vessel_utils.ks

@@ -0,0 +1,112 @@
+run "library/lib_math".
+
+declare function WaitForEngineStart{
+	wait until AnyEngineActive().
+}
+
+declare function AnyEngineActive{
+	list engines in allEngines.
+	for eng in allEngines{
+		if eng:ignition {
+			return true.
+		}
+	}
+	return false.
+}
+
+declare function GetIsp{
+	LIST ENGINES IN allEngines.
+	declare local totalThrust is ship:maxThrust.
+	local sum is 0.
+	local weights is 0.
+	for eng in allEngines{
+		if eng:IGNITION and not eng:flameout{
+			local w is  eng:AVAILABLETHRUST / totalThrust.
+			local ispW is eng:isp * w.
+			set sum to sum + ispW.
+			set weights to weights + w.
+		}
+	}
+	return sum / weights.
+}
+
+declare function GetMaxMassFlow{
+	LIST ENGINES IN allEngines.
+	local sum is 0.
+	for eng in allEngines{
+		if eng:IGNITION and not eng:flameout{
+			set sum to sum + eng:maxmassflow.
+		}
+	}
+	return sum.
+}
+
+declare function CalculateSuicideBurnAltitude
+{
+	parameter vertSpeed.
+	parameter localGravity.
+	parameter tgtAltitude is 0.
+
+	local burnAltitude is ((vertSpeed^2) / (2 * CalculateAverageAcceleration(localGravity))).
+	return burnAltitude + tgtAltitude.
+}
+
+
+declare function CalculateSuicideBurnDuration
+{
+	parameter isp.
+	return CalculateBurnDuration(verticalSpeed, isp, ship:mass, GetMaxMassFlow() * 1000).
+}
+
+declare function CalculateBurnDuration
+{
+	parameter dv.
+	parameter burnIsp.
+	parameter initialMass.
+	parameter massFlow.
+
+	set dv to abs(dv).
+	local exp is -dv / (burnIsp * constant:g0).
+	local massRatio is ApproximateExp(-exp).
+	local finalMass is initialMass / massRatio.
+	local fuelUsed is initialMass - finalMass.
+
+	if massFlow <= 0{
+		return 0.
+	}
+
+	return fuelUsed / massFlow.
+}
+
+
+declare function CalculateAverageAcceleration{
+	parameter localGravity.
+	return ((ship:maxthrust * 1000) / ship:mass) - localGravity.
+}
+
+declare function GetLocalGravity{
+	parameter curAltitude is -1.
+	
+	if curAltitude = -1 {
+		set curAltitude to altitude.
+	}
+	return body:mu / (curAltitude + body:radius)^2.
+}
+
+declare function CalculateTimeToImpact{
+	parameter vertSpeed.
+	parameter curAltitude.
+	parameter gravity.
+	parameter tgtAltitude is 0.
+
+	if gravity <= 0 or curAltitude <= 0{
+		print "[warn]: invalid altitude or gravity.".
+		return 0.
+	}
+
+	local vs is abs(vertSpeed).
+	local g is gravity.
+	local hRel is curAltitude - tgtAltitude.
+	local disc is ((vs^2) + (2 * g * hRel)).
+	return (vs + sqrt(disc)) / g.
+}