public static void main(String[] args) {
        //ExecutorService exec = Executors.newCachedThreadPool();
        //ExecutorService exec = Executors.newFixedThreadPool(3);
        ExecutorService exec = Executors.newSingleThreadExecutor();
        for(int i = 0; i < 10; i++) {
            exec.execute(new LiftOff());
        }
        exec.shutdown();
    }