Linked from

The 76 pages that link to Apollo program, each with the reason it gives.

• NASABroader topic: Apollo became NASA’s defining achievement in crewed lunar exploration.

• John F. KennedyRelated: Kennedy’s 1961 goal of landing a person on the Moon gave the program its defining deadline.

• Apollo 11Narrower topic: Apollo 11 was the program’s first successful crewed lunar landing.

• Fuel cellRelated: Apollo spacecraft used hydrogen–oxygen fuel cells for electricity and potable water.

• Late Heavy BombardmentNarrower topic: Apollo samples made precise dating of ancient lunar rocks possible.

• Systems engineeringBroader topic: Apollo demonstrated system-wide coordination across spacecraft, launch vehicles, ground operations, and contractors.

• Yuri GagarinRelated: The Soviet achievement intensified pressure on the United States to pursue crewed lunar exploration.

• Sergei KorolevCompared with: It became the United States' answer to early Soviet achievements made under Korolev.

• Soviet space programCompared with: Its successful crewed lunar landings contrasted with the Soviet Union’s failure to land cosmonauts there.

• Human spaceflightBroader topic: Apollo marked the first human journeys beyond low Earth orbit and remains the only program to land people on the Moon.

• Wernher von BraunBroader topic: The Saturn V developed under von Braun’s leadership carried Apollo crews to the Moon.

• Apollo command and service moduleNarrower topic: The command and service module was the crewed spacecraft for Apollo lunar missions.

• Apollo Lunar ModuleNarrower topic: The Lunar Module was developed specifically to carry out Apollo’s crewed lunar landings.

• Vostok 1Compared with: The United States' later lunar goal answered the challenge posed by Soviet human-spaceflight achievements.

• Artemis programNarrower topic: Apollo established the precedent Artemis seeks to extend into sustained exploration.

• Saturn VNarrower topic: The Saturn V was built chiefly to carry Apollo crews and spacecraft to the Moon.

• Apollo 13Narrower topic: Apollo 13 was one mission in this broader effort to achieve crewed lunar exploration.

• Project MercuryRelated: Apollo followed Mercury and Gemini in the progression toward lunar exploration.

• Alan ShepardNarrower topic: Shepard’s lunar mission extended the program’s exploration beyond its first landings.

• MoonRelated: Apollo samples transformed hypotheses about lunar age, composition, and formation into testable evidence.

• Apollo–Soyuz Test ProjectNarrower topic: Apollo hardware and flight expertise were adapted for the joint orbital mission.

• Deep Space NetworkCompared with: Apollo’s Earth-orbit and lunar communications used a separate network, unlike the DSN’s deep-space mission focus.

• Neil ArmstrongNarrower topic: Armstrong’s achievement was the most visible milestone of the program.

• Space Shuttle programRelated: The Shuttle was promoted as a follow-on to Apollo’s expensive, expendable launch systems.

• SpaceflightBroader topic: Apollo established crewed lunar travel as a realized form of spaceflight.

• Apollo 8Narrower topic: Apollo 8 was a pivotal early crewed mission in this larger effort.

• Apollo 17Narrower topic: Apollo 17 was its final crewed lunar landing mission.

• Lunar explorationBroader topic: It combined crewed landings with geological fieldwork and sample collection.

• Lunar Reconnaissance OrbiterCompared with: Apollo explored selected sites in person, whereas LRO surveys the Moon remotely from orbit.

• Mercury SevenNarrower topic: Several Mercury Seven astronauts later flew in Apollo missions.

• Operation PaperclipRelated: Paperclip-linked engineers helped build the launch systems that made Apollo missions possible.

• Space suitRelated: Apollo drove suits toward greater mobility and protection for lunar surface work.

• Earth's MoonBroader topic: Apollo missions returned samples that transformed knowledge of lunar geology and history.

• Lunar waterNarrower topic: Apollo samples initially encouraged the view that the Moon was extremely dry.

• National Advisory Committee for AeronauticsNarrower topic: NACA’s engineering workforce and research legacy fed into NASA’s later spaceflight work.

• Space weatheringRelated: Returned lunar soils provided the first abundant samples for studying space-weathered grains.

• Sputnik crisisBroader topic: The crisis-era response to Soviet space achievements preceded the Moon-landing goal.

• Apollo 16Narrower topic: Apollo 16 was one of the program’s crewed lunar landing missions.

• AstronautRelated: Apollo made astronaut fieldwork on another world a reality.

• NASA Astronaut Group 5Narrower topic: The class was chosen chiefly to provide crews for Apollo lunar missions.

• OutgassingRelated: Apollo instruments detected gases near the lunar surface, prompting debate over natural release and spacecraft contamination.

• Apollo 1Narrower topic: Apollo 1 was the first crewed mission planned for the program’s lunar spacecraft.

• Hermann OberthBroader topic: Oberth’s influence on von Braun connected early astronautics to the engineering lineage behind Apollo.

• Luna programCompared with: Apollo used crewed landings, while Luna pursued lunar exploration with robotic spacecraft.

• Mercury-Redstone 3Related: The mission formed an early step in the U.S. effort that later reached the Moon.

• Project GeminiRelated: Gemini’s rendezvous, spacewalk, and endurance experiments prepared techniques Apollo missions relied on.

• Buzz AldrinNarrower topic: Apollo provided the spacecraft, training, and mission framework for Aldrin’s lunar flight.

• Luna 2Related: Luna 2’s impact preceded the eventual shift from robotic lunar reach to human lunar landings.

• Lunar geologic timescaleRelated: Apollo samples transformed relative lunar mapping into a calibrated chronology.

• Fred HaiseNarrower topic: Haise’s Apollo assignments belonged to the program’s lunar exploration era.