static void Main(string[] args)
        {
            PlanetarySystem sys1     = new PlanetarySystem();
            Spaceship       laevJuku = new Spaceship("Juku", sys1);

            laevJuku.Travel(3);
            Spaceship laevKalle = new Spaceship("Kalle", sys1);

            laevKalle.Travel(3);
            laevKalle.Travel(4);
            laevKalle.Travel(3);
            laevKalle.Travel(2);

            AdvancedSpaceship laevPille = new AdvancedSpaceship("Pille", sys1);

            laevPille.Travel(5);
            Console.ReadLine();
        }
 public AdvancedSpaceship(string _spaceshipName, PlanetarySystem _psystem) : base(_spaceshipName, _psystem)
 {
     spaceshipName = _spaceshipName;
     psystem       = _psystem;
     travelLength  = 2;
 }
 public Spaceship(string _spaceshipName, PlanetarySystem _psystem)
 {
     spaceshipName = _spaceshipName;
     psystem       = _psystem;
     travelLength  = 1;
 }