public static void DoAirlaunch(AirlaunchParams launchParams)
{
CelestialBody body = FlightGlobals.currentMainBody;
Vessel vessel = FlightGlobals.ActiveVessel;
// SpaceCenter.Instance.transform doesn't work correctly with RSS + KSCSwitcher installed
PQSCity ksc = KCT_Utilities.FindKSC(body);
Vector3d kscPosition = ksc.transform.position - body.position;
Vector3d kscUp = kscPosition.normalized;
Vector3d kscEast = Vector3d.Cross(body.angularVelocity, kscPosition).normalized;
Vector3d kscNorth = Vector3d.Cross(kscEast, kscUp);
double kscAltitude = kscPosition.magnitude - body.Radius;
// From https://www.movable-type.co.uk/scripts/latlong-vectors.html#midpoint
var δ = launchParams.KscDistance / body.Radius;
var d = kscNorth * Math.Cos(Mathf.Deg2Rad * launchParams.KscAzimuth) + kscEast * Math.Sin(Mathf.Deg2Rad * launchParams.KscAzimuth);
var teleportPosition = kscPosition * Math.Cos(δ) + body.Radius * d * Math.Sin(δ);
teleportPosition += teleportPosition.normalized * (launchParams.Altitude - kscAltitude);
Vector3d up = teleportPosition.normalized;
Vector3d east = Vector3d.Cross(body.angularVelocity, teleportPosition).normalized;
Vector3d north = Vector3d.Cross(east, up);
Vector3d teleportVelocity = Vector3d.Cross(body.angularVelocity, teleportPosition);
teleportVelocity += (Math.Sin(Mathf.Deg2Rad * launchParams.LaunchAzimuth) * east + Math.Cos(Mathf.Deg2Rad * launchParams.LaunchAzimuth) * north) * launchParams.Velocity;
// counter for the momentary fall when on rails
teleportVelocity += up * (body.gravParameter / teleportPosition.sqrMagnitude / 2);
teleportPosition = teleportPosition.xzy;
teleportVelocity = teleportVelocity.xzy;
Vector3d to = teleportPosition.xzy.normalized;
Quaternion rotation = Quaternion.LookRotation(-to);
rotation *= Quaternion.AngleAxis((float)launchParams.LaunchAzimuth, Vector3.back);
Orbit orbit = vessel.orbitDriver.orbit.Clone();
orbit.UpdateFromStateVectors(teleportPosition, teleportVelocity, body, Planetarium.GetUniversalTime());
vessel.SetOrbit(orbit);
vessel.SetRotation(rotation);
ResetGroundContact(vessel);
}