ball2.ks

function GETDENSITY {
	parameter altitude.
	set LOWDENS TO 0.
	set HIGHDENS TO 0.
	SET MIX TO 1.
	if (altitude < 2500)
	{
		SET LOWDENS TO 1.225.
		SET HIGHDENS TO 0.898.
		SET MIX TO altitude/2500.
	} else if (altitude < 5000)
	{
		SET LOWDENS TO 0.898.
		SET HIGHDENS TO  0.642 .
		SET MIX TO (altitude-2500)/2500.
	} else if (altitude < 7500)
	{
		SET LOWDENS TO  0.642 .
		SET HIGHDENS TO 0.446.
		SET MIX TO (altitude-5000)/2500.
	} else if (altitude < 10000)
	{
		SET LOWDENS TO 0.446.
		SET HIGHDENS TO 0.288.
		SET MIX TO (altitude-7500)/2500.
	} else if (altitude < 15000)
	{
		SET LOWDENS TO 0.288.
		SET HIGHDENS TO 0.108 .
		SET MIX TO (altitude-10000)/5000.
	} else if (altitude < 20000)
	{
		SET LOWDENS TO 0.108.
		SET HIGHDENS TO 0.040 .
		SET MIX TO (altitude-15000)/5000.
	} else if (altitude < 25000)
	{
		SET LOWDENS TO 0.040 .
		SET HIGHDENS TO  	0.015 .
		SET MIX TO (altitude-20000)/5000.
	} else if (altitude < 30000)
	{
		SET LOWDENS TO  	0.015 .
		SET HIGHDENS TO 0.006 .
		SET MIX TO (altitude-25000)/5000.
	} else if (altitude < 40000)
	{
		SET LOWDENS TO 0.006 .
		SET HIGHDENS TO 0.001.
		SET MIX TO (altitude-30000)/10000.
	} else if (altitude < 70000)
	{
		SET LOWDENS TO 0.001.
		SET HIGHDENS TO 0.0001.
		SET MIX TO (altitude-40000)/30000.
	} else
	{
		RETURN 0.
	}
	RETURN (LOWDENS*(1-MIX))+(HIGHDENS*(MIX)).
}.
	
function GETBALLISTICX {
	parameter STARTINGALT.
	parameter Uo.
	parameter Vo.
	parameter Cd.
	
	SET g to body:mu / (STARTINGALT + body:radius)^2.
	SET Vt TO SQRT((2*SHIP:MASS*g)/(Cd*Density)).
	SET ESTFALLTIME TO (Vo/g)*2.
	SET ymax TO (Vt^2 / (2 * g)) * ln ((Vo^2 + Vt^2)/Vt^2).
	SET ITERATIONS TO 10.
	UNTIL (ITERATIONS = 0)
	{

		SET NEWG TO body:mu / ((STARTINGALT+ymax) + body:radius)^2.
		SET Vt TO SQRT((2*SHIP:MASS*NEWG)/(Cd*GETDENSITY((STARTINGALT+ymax)/2))).
		SET ymax TO (Vt^2 / (2 * NEWG)) * ln ((Vo^2 + Vt^2)/Vt^2).
		SET AVGG TO (g+NEWG)/2.
		SET FALLTIMENEW TO (Vo/AVGG)*2.
		
		SET X TO ((Vt*Vt)/AVGG)*(LN(((Vt*Vt)+AVGG*Uo*FALLTIMENEW)/(Vt*Vt))).
		
		SET ITERATIONS TO ITERATIONS - 1.
	}.
	RETURN X.
}

function PRINTDATA {
	LOCK CALCHORV TO COS((ARCSIN(SHIP:VERTICALSPEED/SHIP:AIRSPEED)))*SHIP:AIRSPEED.
	IF (SHIP:VERTICALSPEED > 0)
	{
		PRINT "CURRENT X:" + GETBALLISTICX(ALTITUDE, SHIP:VERTICALSPEED, CALCHORV, Cd) at (20,0).
	}.
	PRINT "KSCDIST: " + KSCSPOT:DISTANCE AT (20,1).
	PRINT "KSDCLOSING: "+ KSCCLOSINGV AT (20,2).
	PRINT "STAGE: " + MISSIONSTAGE AT (20,3).
}

CLEARSCREEN.

SET Cd TO 0.007.
SET Density TO 1.225.
SET MISSIONSTAGE TO 0.
SET KSCALT TO ALTITUDE.
SET KSCSPOT to SHIP:GEOPOSITION.
SET LASTKSCDIST TO KSCSPOT:DISTANCE.
SET KSCCLOSINGV TO 0.
SET KSCGEO TO SHIP:GEOPOSITION.
LOCK CALCHORV TO COS((ARCSIN(SHIP:VERTICALSPEED/SHIP:AIRSPEED)))*SHIP:AIRSPEED.

SET DELTATIME TO 0.1.
SET LASTTIME TO TIME:SECONDS.
WAIT 0.01.
SET DELTATIME TO TIME:SECONDS - LASTTIME.
STAGE.
UNTIL (FALSE)
{
	PRINTDATA().
	WAIT 0.01.
	SET DELTATIME TO TIME:SECONDS - LASTTIME.
	SET LASTTIME TO TIME:SECONDS.
	SET ABOVEKSC TO LATLNG(KSCGEO:LAT,KSCGEO:LNG):ALTITUDEPOSITION(ALTITUDE).
	SET KSCDIST TO SHIP:GEOPOSITION:LNG - KSCSPOT:LNG.
	SET KSCCLOSINGV TO (KSCDIST-LASTKSCDIST)/DELTATIME.
	SET LASTKSCDIST TO KSCDIST.
	IF (MISSIONSTAGE = 0)
	{
			LOCK STEERING TO HEADING(90,85 + (15 * (1-((1500-ALTITUDE)/1500)))).
			LOCK THROTTLE TO 1.0.
			IF (ALTITUDE > 1500)
			{
				SET MISSIONSTAGE TO 1.
			}
	}
	IF (MISSIONSTAGE = 1)
	{
			//LOCK STEERING TO LATLNG(KSCGEO:LAT,KSCGEO:LNG):ALTITUDEPOSITION(ALTITUDE).
			LOCK STEERING TO HEADING(270,70).
			LOCK THROTTLE TO 1.0.
			SET BALLX TO GETBALLISTICX(ALTITUDE, SHIP:VERTICALSPEED, CALCHORV, Cd).
	
			IF (BALLX > KSCDIST AND KSCCLOSINGV < 0)
			{
				SET MISSIONSTAGE TO 2.
			}
	}
	IF (MISSIONSTAGE = 2)
	{
			LOCK STEERING TO HEADING(270,90).
			LOCK THROTTLE TO 0.0.
	}
}.