// A simple kerboscript code to launch a rocketship to orbit
// Assumes a standard rocket design with a single stage and a fairing
// Adjust the target altitude, inclination, and heading as needed

// Set the target altitude in meters
set targetAlt to 100000.

// Set the target inclination in degrees
set targetInc to 0.

// Set the launch heading in degrees
set launchHeading to 90 - targetInc * cos(LATITUDE).

// Set the initial pitch angle in degrees
set pitchAngle to 90.

// Set the pitch program parameters
set pitchStartAlt to 1000. // The altitude to start pitching down
set pitchEndAlt to 45000. // The altitude to end pitching down
set pitchEndAngle to 10. // The final pitch angle

// Set the steering parameters
set maxSteer to 0.05. // The maximum steering error allowed
set steerFactor to 0.5. // The steering correction factor

// Set the throttle parameters
set maxThrottle to 1. // The maximum throttle level
set minThrottle to 0.1. // The minimum throttle level
set throttleFactor to 0.1. // The throttle correction factor

// Set the circularization parameters
set circBurnAlt to 70000. // The altitude to start circularization burn
set circBurnTolerance to 10. // The tolerance for circularization burn

// Lock the throttle and steering
lock throttle to maxThrottle.
lock steering to heading(launchHeading, pitchAngle).

// Wait for launch clamps to release
wait until STAGE:READY.

// Start the main engine and stage
stage.

// Print some information
print "Launching rocketship to orbit.".
print "Target altitude: " + round(targetAlt) + " m.".
print "Target inclination: " + round(targetInc) + " deg.".
print "Launch heading: " + round(launchHeading) + " deg.".

// Main ascent loop
until apoapsis > targetAlt {

    // Update the pitch angle according to the pitch program
    if altitude > pitchStartAlt and altitude < pitchEndAlt {
        set pitchAngle to map(altitude, pitchStartAlt, pitchEndAlt, 90, pitchEndAngle).
    } else if altitude >= pitchEndAlt {
        set pitchAngle to pitchEndAngle.
    }

    // Update the steering according to the prograde vector and the pitch angle
    lock steering to lookdirup(vxcl(up:vector, ship:velocity:surface), up:vector) + R(0, -maxSteer, 0) * steerFactor * (pitchAngle - vang(ship:facing:forevector, ship:velocity:surface)).

    // Update the throttle according to the apoapsis error and the throttle factor
    lock throttle to max(minThrottle, min(maxThrottle, maxThrottle - throttleFactor * (apoapsis - targetAlt))).

    // Print some information
    print "Altitude: " + round(altitude) + " m." at (0,0).
    print "Apoapsis: " + round(apoapsis) + " m." at (0,1).
    print "Pitch angle: " + round(pitchAngle) + " deg." at (0,2).
    print "Throttle: " + round(throttle * 100) + " %" at (0,3).

}

// Cut off the engine and coast to the circularization burn altitude
lock throttle to 0.
print "Coasting to circularization burn altitude.".

// Wait until the circularization burn altitude is reached
wait until altitude > circBurnAlt.

// Calculate the circularization burn delta-v and time-to-node
set circNode to node(time:seconds + eta:apoapsis, 0, 0, sqrt(body:mu / apoapsis) - ship:orbit:velocityat(time:seconds + eta:apoapsis):orbit:mag).
set circDV to circNode:deltav:mag.
set circBurnTime to circDV / ship:maxthrust * ship:mass.
set circTimeToNode to circNode:eta - circBurnTime / 2.

// Orient the ship towards the node and wait for the node time
lock steering to circNode.
wait until circTimeToNode < 0.

// Start the circularization burn and loop until the delta-v is close enough
lock throttle to maxThrottle.
print "Starting circularization burn.".
until circNode:deltav:mag < circBurnTolerance {

    // Print some information
    print "Delta-v: " + round(circNode:deltav:mag) + " m/s." at (0,4).
    print "Time to node: " + round(circTimeToNode) + " s." at (0,5).

}

// Cut off the engine and remove the node
lock throttle to 0.
remove circNode.
print "Circularization burn complete.".

// Deploy the fairing and unlock the steering
if ship:fairing.
    stage.
    print "Fairing deployed.".
unlock steering.

// Print the final orbit information
print "Orbit achieved.".
print "Apoapsis: " + round(apoapsis) + " m.".
print "Periapsis: " + round(periapsis) + " m.".
print "Inclination: " + round(inclination) + " deg.".

// End of script