Apollo 12
Apollo 12 was the sixth crewed mission in NASA's Apollo program and the second to successfully land humans on the Moon, achieving a precision touchdown in the Ocean of Storms on November 19, 1969, just 163 meters from the unmanned Surveyor 3 probe.[1] Launched atop a Saturn V rocket from Kennedy Space Center on November 14, 1969, at 11:22 a.m. EST, the mission faced immediate drama when the vehicle was struck by lightning twice shortly after liftoff, temporarily knocking out instrumentation until quick thinking by mission control restored systems.[1] The crew consisted of Commander Charles "Pete" Conrad Jr., Lunar Module Pilot Alan L. Bean, and Command Module Pilot Richard F. Gordon Jr., who remained in lunar orbit while Conrad and Bean conducted two extravehicular activities (EVAs) totaling nearly eight hours on the surface.[2] During their 31 hours and 31 minutes on the Moon, the astronauts deployed the Apollo Lunar Surface Experiments Package (ALSEP), a set of scientific instruments including a seismometer and solar wind spectrometer that operated until 1977, gathering data on lunar quakes and the solar environment.[3] They also retrieved components from Surveyor 3, such as its camera and scoop, for return to Earth to study microbial contamination and material degradation in the lunar vacuum, marking the first retrieval of hardware from another space mission.[1] The crew collected approximately 34 kilograms (75 pounds) of lunar rocks and soil, primarily basalts dated to 3.1–3.3 billion years old, providing key insights into the Moon's volcanic history.[3] Notably, Bean accidentally pointed the color television camera toward the Sun during the first EVA, destroying it and ending live broadcasts prematurely, though Gordon's orbital photography contributed to certifying landing sites for future missions like Apollo 14.[3] The mission concluded with a splashdown in the Pacific Ocean on November 24, 1969, after 10 days, 4 hours, and 36 minutes in space, during which the command module orbited the Moon 45 times.[3] Apollo 12 demonstrated enhanced landing accuracy and expanded scientific capabilities compared to Apollo 11, paving the way for subsequent lunar explorations while returning safely with invaluable samples and data that advanced understanding of the Moon's geology and environment.[1]Mission Background
Objectives and planning
Apollo 12, as NASA's second crewed lunar landing mission, had primary objectives centered on demonstrating precision landing capabilities near the unmanned Surveyor 3 probe, which had soft-landed in the Ocean of Storms on April 20, 1967.[4] The crew was tasked with conducting two extravehicular activities (EVAs) totaling approximately 7.5 hours to perform selenological inspections, sample collection, and surface exploration.[5] Additional key goals included deploying the Apollo Lunar Surface Experiments Package (ALSEP), consisting of instruments such as a seismometer, magnetometer, and solar wind spectrometer, to enable long-term measurements of lunar seismic activity, magnetic fields, and other environmental data.[5] The astronauts also aimed to retrieve components from Surveyor 3, including its camera and scoop, for post-mission analysis to assess the effects of the lunar environment on Earth hardware.[4] Secondary objectives focused on testing enhancements to the Lunar Module's guidance and navigation systems for improved accuracy, gathering geological samples from diverse terrains in Oceanus Procellarum to expand understanding of mare basalts, and obtaining photographs of the landing site and nearby features to support planning for subsequent Apollo missions.[5] The mission was planned for a duration of about 10 days, incorporating a hybrid non-free-return trajectory to allow flexibility in lunar orbit operations and a daylight launch.[5] Planning for Apollo 12 advanced in the late 1960s as part of the broader Apollo program, with the landing site selected in 1968 based on Surveyor 3 imagery and data, targeting coordinates at approximately 3° S, 23° 42' W within a 200–600 meter radius of the probe to validate pinpoint landing techniques.[1][6] In contrast to Apollo 11, which emphasized a general proof-of-concept landing and a single 2.5-hour EVA with about 21 hours on the surface, Apollo 12 prioritized targeted precision (aiming for within 200 meters of Surveyor 3), extended surface operations totaling 31 hours across two EVAs, and the introduction of ALSEP for ongoing science.[5] It also incorporated a color television camera for real-time surface broadcasts, though this was inadvertently damaged early in the mission.[5] As the follow-up to Apollo 11's success in July 1969, Apollo 12 sought to build operational momentum toward longer lunar stays in later missions, within the context of the $25.4 billion Apollo program authorized under President Kennedy's 1961 directive.[7]Site selection
The selection of the Apollo 12 landing site prioritized a flat mare basalt terrain in the Oceanus Procellarum region to ensure a safe landing, given the mission's emphasis on precision navigation and surface operations.[8] Key criteria included proximity to the Surveyor 3 spacecraft, which had landed on April 20, 1967, at coordinates approximately 3.0° S, 23.42° W, to allow for retrieval of components during extravehicular activity within a 1-km radius; optimal solar illumination angles of 5 to 14 degrees for the planned 31-hour surface stay, facilitating visibility and thermal control; and favorable Earth visibility for real-time television coverage of activities.[9][6] These factors were evaluated against engineering feasibility, such as trajectory compatibility and low risk of local electromagnetic disturbances, while balancing scientific objectives like deploying the Apollo Lunar Surface Experiments Package (ALSEP).[10] The selection process began with a pool of candidate sites identified in 1968 using high-resolution imagery from the Lunar Orbiter missions, which provided orbital reconnaissance to map potential areas in the lunar maria.[10] For Apollo 12, the primary site—designated Site 7 at approximately 3° S, 23° W—was narrowed from initial options including Sites 2, 3, and 5, based on its location in the southeastern Oceanus Procellarum along a Copernicus ray.[5] Confirmation came from Surveyor 3's surface photographs, which depicted smooth plains interspersed with craters 1 to 2 meters in diameter, verifying the terrain's suitability for a pinpoint landing.[8] The NASA Apollo Site Selection Board provided final approval on July 10, 1969, after integrating these data with mission planning inputs from geologists and engineers, ensuring alignment with overall lunar exploration goals.[11] Backup sites were prepared as contingencies for launch delays or abort scenarios, with Site 5 at 2.0° N, 42.0° W in a younger mare area south of Kepler serving as the primary alternate, and Site 2 in the Fra Mauro formation as a secondary option.[5][6] These alternatives maintained similar mare characteristics but offered flexibility in longitude to accommodate potential trajectory adjustments.[10] Site 3, another mare region, was also considered in early evaluations but deprioritized due to lower geological homogeneity compared to Site 7.[5] Geologically, the chosen site targeted layered basaltic formations in the Oceanus Procellarum to investigate the Moon's volcanic history, focusing on homogeneous mare materials representative of lunar provinces rather than highland terrains reserved for later missions.[8] This allowed for systematic sampling of regolith and rocks to compare with Apollo 11 findings from the Sea of Tranquility, emphasizing prolonged mare-filling processes and ejecta from secondary impacts like those from Copernicus.[10] The proximity to Surveyor 3 further enabled direct assessment of surface evolution over 31 months, including dust accumulation and micrometeoroid effects on exposed hardware.[8] Challenges in site selection centered on risks associated with the precision landing requirement, such as potential touchdown in the shadow of Surveyor 3 or on uneven micro-terrain hidden in Orbiter images, which could complicate solar-powered operations or ascent.[5] These were mitigated through detailed pre-mission analysis, including construction of 1:1 scale terrain models based on Surveyor 3 imagery and Lunar Orbiter data, which informed crew training on navigation landmarks like the distinctive "snowman" crater pattern.[5] Overall, the process underscored a shift toward targeted scientific returns while upholding safety margins established from Apollo 11.[10]Crew and Personnel
Prime and backup crews
The prime crew for Apollo 12 consisted of Commander Charles "Pete" Conrad Jr., Command Module Pilot Richard F. Gordon Jr., and Lunar Module Pilot Alan L. Bean.[12] All three were selected as part of NASA's second astronaut group in 1962 and were naval aviators with extensive test pilot backgrounds prior to joining the agency.[13][14][15] Conrad, aged 39 at launch, commanded the mission and served as the lunar landing pilot, drawing on his prior command of Gemini 5 and Gemini 11, which provided over 260 hours of spaceflight experience focused on long-duration flight and rendezvous operations suitable for the mission's precision landing near Surveyor 3.[13][16] Gordon, aged 40, handled solo operations in the Command and Service Module (CSM) Yankee Clipper during the lunar excursion, leveraging his approximately 70 hours from Gemini 11, where he demonstrated expertise in rendezvous and extravehicular activity support.[14] Bean, aged 37 on a first spaceflight, acted as Lunar Module (LM) pilot and provided EVA support on the lunar surface, bringing his Navy pilot qualifications to the role.[15] The crew was noted for its close-knit dynamics and Conrad's characteristic humor, fostering a lighthearted yet professional atmosphere during training and flight.[16]| Position | Astronaut | Age at Launch | Prior Spaceflights | Spaceflight Hours (Approximate) |
|---|---|---|---|---|
| Commander | Charles "Pete" Conrad Jr. | 39 | Gemini 5, Gemini 11 | 260+ |
| Command Module Pilot | Richard F. Gordon Jr. | 40 | Gemini 11 | 70 |
| Lunar Module Pilot | Alan L. Bean | 37 | None | 0 |
| Position | Astronaut | Age at Launch | Prior Spaceflights | Spaceflight Hours (Approximate) |
|---|---|---|---|---|
| Commander | David R. Scott | 37 | Gemini 8, Apollo 9 | 250+ |
| Command Module Pilot | James B. Irwin | 39 | None | 0 |
| Lunar Module Pilot | John W. Young | 39 | Gemini 3, Gemini 10, Apollo 10 | 270+ |