From the Earth to the Moon (1958) on Netflix

Soon after the end of the American Civil War, arms manufacturer Victor Barbicane announces that he has produced a powerful new weapon. known as Power X. He asks Confederate supporter and steel manufacturer Stuyvesant Nicholl to make his best armor plate which Barbicane has no trouble destroying. After the President asks him not to pursue his new weapon, Barbicane decides on a new venture: a trip to the moon. He enlists Nicholl to invent a new covering for his rocket, one that will protect the ship when it reenters the Earth's atmosphere on the return voyage. Unknown to Barbicane however is Nicholl's hatred for the arms dealer and his intention to sabotage the journey.