The reason why Liu Hai said that the rocket engine was OK was that there were many missiles on the aircraft carrier. Some of these missiles used solid rocket engines, and some used liquid rocket engines.
In fact, many people have a misunderstanding that liquid rocket motors are not as good as solid rocket motors.
But just in space, liquid rockets have great advantages. First, liquid rockets can ignite twice.
If you want to land on the moon or Mars, you need to use liquid rocket engines.
That is to say, when the rocket landing on the moon lands on the moon and returns, the rocket motor will be started again, and the solid rocket will launch