public string[] gps_list = { 
"GPS:Laser Antenna:13.98:-6.36:13.48:", 
"GPS:Laser Antenna:-16.55:-2.32:36.31:", 
"GPS:Laser Antenna:-41.55:-9.82:8.81:",
"GPS:Laser Antenna:-16.55:-7.32:-16.19:"
};

public int timer = 0;
public int selected = 0;
public Vector3D last_target = new Vector3D(0,0,0);
public IMyLaserAntenna antenna;
public Program()
{
    Runtime.UpdateFrequency = UpdateFrequency.Update1;
    antenna = GridTerminalSystem.GetBlockWithName("123") as IMyLaserAntenna;
    antenna.SetTargetCoords(gps_list[selected]);
    antenna.Connect();
}
public void Main(string argument, UpdateType updateSource)
{
	timer++;
    if (timer % (60 * 10) == 0)
    {
        selected = (selected + 1) % 4;
        antenna.SetTargetCoords(gps_list[selected]);
        antenna.Connect();
    }
}