Given the time in which he was writing, Verne's predictions were very good.
The size of his space ship was about the size of the first one to go to the moon, the Apollo, minus its large rockets.
Both Verne's ship and the Apollo carried three people into space.
Furthermore, rockets were indeed used by the Apollo to slow its descent.
However, Verne's ship shot his travelers into space, which never the moon on July 16, 1969. could have worked.
The intense pressure of firing a spaceship the way one would fire a bullet from a gun would cause great physiological damage to the crew.