From the Earth to the Moon and Round the Moon recap

After the American Civil War, Gun Club president Impey Barbicane proposes firing a projectile to the Moon from a gigantic cannon in Florida. The plan becomes an international spectacle. French adventurer Michel Ardan asks to ride inside the shell; Barbicane and his rival Captain Nicholl ultimately join him. The launch succeeds, but a passing body deflects the projectile enough to prevent a lunar landing. The three men and two dogs survive weightlessness, observe the Moon at close range, and pass around its far side. They use rockets in an effort to escape an apparently endless orbit, sending the capsule back toward Earth. It splashes into the Pacific near the Susquehanna. Searchers first fear it has sunk, then find the buoyant projectile floating with all three men alive. The voyage has not reached the lunar surface, but it has carried human observers around the Moon and safely home.

With the American Civil War over, the Baltimore Gun Club's artillery specialists have lost the work that defined them. Their president, Impey Barbicane, offers a new project grand enough to employ all their skill: build a cannon capable of sending a projectile to the Moon. Cambridge Observatory supplies the required speed, timing, and trajectory, establishing a narrow launch window in December of the following year. Barbicane presents the calculation as an engineering problem rather than a fantasy. Newspapers and the public seize on the plan, and subscriptions arrive from around the world. The Gun Club begins debating the material and dimensions of the projectile and the enormous weapon that must launch it, while secretary J. T. Maston embraces every part of the enterprise with fervor.

The Gun Club chooses a massive cast-iron cannon, the Columbiad, driven by a powerful explosive charge. Florida wins the dispute over the launch site because its latitude suits the planned trajectory, and Stones Hill is selected. Captain Murchison directs workers as they excavate a deep shaft, build the mold, and perform the difficult casting. Meanwhile Captain Nicholl, a Philadelphia armor specialist and Barbicane's technical rival, publishes objections to each stage and makes wagers that the project will fail. The metal cools successfully, the bore is prepared, and the construction becomes the center of a booming settlement and a vast public festival. The physical means of firing an unoccupied shell toward the Moon now exists, though the violence of the acceleration still appears to rule out human travel.

A telegram from French adventurer Michel Ardan asks the Gun Club to replace its solid shell with a hollow projectile and let him travel inside. Ardan arrives by ship and wins over an enormous audience with his confidence in exploration and progress. Captain Nicholl challenges him and renews his hostility toward Barbicane. Ardan discovers that the two rivals intend to settle their dispute in a duel, finds them before either is harmed, and proposes a more constructive resolution: both should accompany him. Barbicane and Nicholl agree. The experiment is transformed into a crewed voyage by three very different men—its calculating director, his skeptical rival, and the imaginative Frenchman who united them.

The aluminum projectile is rebuilt as a padded, airtight cabin with stored provisions, water, gas, oxygen-producing chemicals, and rockets. A great telescope is erected in the Rocky Mountains to follow its path. Barbicane, Nicholl, and Ardan enter with two dogs while crowds gather at a safe distance. The Columbiad fires at the appointed instant and the shell vanishes into the sky. Heavy cloud prevents immediate observation. When the telescope can finally be used, the watchers conclude that the projectile was deflected and has not struck the Moon. It appears to have become a small satellite traveling around it. The public does not yet know whether the three passengers survived the launch or what conditions they face beyond Earth.

Inside the projectile, the travelers recover from the launch and discover that the initial shock was survivable. One dog, injured during departure, dies and is released into space. Barbicane reconstructs their route and identifies the cause of the deviation: a small wandering body passed near them soon after launch and altered their course. The men experience weightlessness as the opposing attractions of Earth and Moon temporarily balance. Their cabin's air and heat systems continue to function, and they use its windows to observe the approaching lunar surface. Although the planned impact will not occur, they hope their curved path may still bring them close enough to study the Moon before determining whether they can ever return.

The projectile sweeps over the Moon at close range. Barbicane and Nicholl methodically identify mountains, craters, plains, and brilliant ray systems, while Ardan repeatedly imagines what life or exploration there might be. Their observations reveal a stark landscape but no clear evidence of living inhabitants. Passing into the long lunar night removes the warmth of direct sunlight and leaves them vulnerable to severe cold. A sudden bright meteor illuminates part of the hidden hemisphere, giving them a brief view unavailable from Earth. Their course then carries them away from the Moon. Calculations suggest they may be following a path that will not naturally return to Earth, turning a successful close passage into the threat of permanent exile in space.

With no possibility of steering conventionally, the three men decide to fire the projectile's rockets and gamble on changing its path. On Earth, observers lose track of the capsule until the American warship Susquehanna, taking Pacific soundings, sees a brilliant object strike the ocean. Maston and Gun Club veterans join an urgent recovery effort. Initial calculations place the projectile on the seabed at a depth beyond easy reach, and preparations begin for an unprecedented salvage. Maston then recognizes that the hollow aluminum shell is buoyant. The search shifts to the surface, where the capsule is found floating. Barbicane, Nicholl, and Ardan are alive inside, calmly occupied while awaiting discovery. They return as international heroes. Their rockets sent them back to Earth rather than into lunar orbit; although they did not land, they completed a voyage around the Moon and survived.

After passing close to the Moon, the projectile is carried away on a path that may never return to Earth. Barbicane, Nicholl, and Ardan fire their rockets in the hope of altering that course. The maneuver succeeds, though not in the way they expected: the capsule falls back toward Earth and plunges into the Pacific. The American warship Susquehanna is nearby taking depth soundings and witnesses the impact. A search begins, led by Maston and other Gun Club members, but the projectile initially appears lost at an immense depth. The searchers then realize that its light aluminum body should float. They find it on the surface, with its occupants alive inside and calmly passing the time. The three travelers return as celebrated survivors. They did not land on the Moon, but they circled it, observed regions never seen from Earth, and came home together, leaving open the possibility of a future attempt.