try suborbital flight in KSP controlled via kRPC, tested in LINQPad with GDLV3 (Stock)

KSP_kRPC_spike

// fetch Google.Protobuf and KRPC.Client from nuget gallery
// namespace imports:
//KRPC.Client
//KRPC.Client.Services.SpaceCenter
//System
// removed due to ambiguity with linq expressions: KRPC.Client.Services.KRPC

// based on https://krpc.github.io/krpc/tutorials/suborbital-flight.html, LGPL
class SubOrbitalFlight
{
	public static readonly System.Net.IPAddress kspKrpcServer = System.Net.IPAddress.Parse("ipv4/ipv6 of machine running ksp");
	
	public static void Main()
	{
		using (var conn =	new Connection("kspRpcSpike", kspKrpcServer))// use default port
		{

			var vessel = conn.SpaceCenter().ActiveVessel;

			vessel.AutoPilot.TargetPitchAndHeading(90, 90);
			vessel.AutoPilot.Engage();
			vessel.Control.Throttle = 1;
			System.Threading.Thread.Sleep(1000);
			
			Console.WriteLine("Launch!");
			vessel.Control.ActivateNextStage();
			
			{
				var solidFuel = Connection.GetCall(() => vessel.Resources.Amount("SolidFuel"));
				var expr = KRPC.Client.Services.KRPC.Expression.LessThan(
					conn, 
					KRPC.Client.Services.KRPC.Expression.Call(conn, solidFuel), 
					KRPC.Client.Services.KRPC.Expression.ConstantFloat(conn, 0.1f)
				);
				var evnt = conn.KRPC().AddEvent(expr);
				lock (evnt.Condition)
				{
					evnt.Wait();
				}
			}
	
			Console.WriteLine("Booster separation");
			vessel.Control.ActivateNextStage();
	
			{
				var meanAltitude = Connection.GetCall(() => vessel.Flight(null).MeanAltitude);
				var expr = KRPC.Client.Services.KRPC.Expression.GreaterThan(
					conn, 
					KRPC.Client.Services.KRPC.Expression.Call(conn, meanAltitude), 
					KRPC.Client.Services.KRPC.Expression.ConstantDouble(conn, 10000)
				);
				var evnt = conn.KRPC().AddEvent(expr);
				lock (evnt.Condition)
				{
					evnt.Wait();
				}
			}
	
			Console.WriteLine("Gravity turn");
			vessel.AutoPilot.TargetPitchAndHeading(60, 90);
	
			{
				var apoapsisAltitude = Connection.GetCall(() => vessel.Orbit.ApoapsisAltitude);
				var expr = KRPC.Client.Services.KRPC.Expression.GreaterThan(
					conn, 
					KRPC.Client.Services.KRPC.Expression.Call(conn, apoapsisAltitude), 
					KRPC.Client.Services.KRPC.Expression.ConstantDouble(conn, 100000)
				);
				var evnt = conn.KRPC().AddEvent(expr);
				lock (evnt.Condition)
				{
					evnt.Wait();
				}
			}
	
			Console.WriteLine("Launch stage separation");
			vessel.Control.Throttle = 0;
			System.Threading.Thread.Sleep(1000);
			vessel.Control.ActivateNextStage();
			vessel.AutoPilot.Disengage();
	
			{
				var srfAltitude = Connection.GetCall(() => vessel.Flight(null).SurfaceAltitude);
				var expr = KRPC.Client.Services.KRPC.Expression.LessThan(
					conn, 
					KRPC.Client.Services.KRPC.Expression.Call(conn, srfAltitude), 
					KRPC.Client.Services.KRPC.Expression.ConstantDouble(conn, 1000));
				var evnt = conn.KRPC().AddEvent(expr);
				lock (evnt.Condition)
				{
					evnt.Wait();
				}
			}
	
			vessel.Control.ActivateNextStage();
	
			while (vessel.Flight(vessel.Orbit.Body.ReferenceFrame).VerticalSpeed < -0.1)
			{
				Console.WriteLine("Altitude = {0:F1} meters", vessel.Flight().SurfaceAltitude);
				System.Threading.Thread.Sleep(1000);
			}
			Console.WriteLine("Landed!");
			//autodispose since where in a using-environment: conn.Dispose();
		}
	}
}