Apollo 14: Investigation and Coordinated Measurements in the Fra Mauro Highlands

Apollo 14's central scientific objectives were to investigate the Fra Mauro formation, collect rocks and lunar soil, deploy surface experiments and photograph possible future exploration sites. The area was thought to preserve ejecta associated with the formation of the Imbrium basin. The young Cone crater might also have brought material beneath the cover to the surface, giving the site research value distinct from earlier landings in the lunar maria.

NASA assigned Alan Shepard as commander, Edgar Mitchell as lunar module pilot and Stuart Roosa as command module pilot. While the first two worked on the surface, Roosa remained in orbit taking photographs and conducting scientific tasks, with ground personnel supporting both activities through communications, tracking and telemetry.

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Improvements following the Apollo 13 failure were incorporated directly into this spacecraft. The mission report listed added equipment including a third cryogenic oxygen tank, isolation valves and a backup battery, while fans were removed from inside the oxygen tanks and wiring changed. These modifications increased isolation and reserve capacity for oxygen supply and required renewed examination of connections between electrical power and environmental-control systems.

At approximately 21:03 on January 31, 1971, a Saturn V launched from Kennedy Space Center, Florida; times here are consistently given in Greenwich Mean Time. Bad weather delayed launch by about forty minutes. After the spacecraft entered its lunar-bound trajectory, docking difficulties prevented a successful connection until the sixth attempt, and the crew inspected the system before continuing.

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The spacecraft entered lunar orbit on February 4 and landed in the Fra Mauro highlands at about 09:18 on February 5. Entering lunar orbit and physically touching the surface were distinct stages. Roosa remained in orbit while Shepard and Mitchell descended.

Before descent, a faulty abort switch sent an abort signal to the computer without crew action. Ground personnel and crew worked together, entering a program to inhibit responses to the spurious signal. A landing-radar range problem was resolved by cycling the circuit. Completing the mission depended on recognizing telemetry anomalies and promptly adjusting operations, not on equipment functioning without error throughout.

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The two lunar-surface excursions were scheduled for February 5 and 6. The first focused on unloading and installing the Apollo Lunar Surface Experiments Package and collecting samples; the second was a geological traverse toward Cone crater. A newly carried hand-pulled Modular Equipment Transporter moved tools and samples, but uneven terrain and positioning difficulties still limited travel efficiency. The crew returned about 43 kilograms of lunar material, with photographs and field descriptions supplying location context.

In 2010, Jessica Marquez compared the first excursion's plan and actual execution task by task and found substantial delays caused by unloading, connecting and positioning experiments. Shepard's photography also had to be coordinated with Mitchell's active seismic work: he had to stop moving during signal generation to avoid interference. Even two astronauts working simultaneously could therefore have to wait for one another because of a single experiment's requirements.

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Researchers including Robert Kovach and Tom Landers of Stanford University and Joel Watkins of the University of North Carolina conducted the active seismic experiment. The crew placed three geophones along a line and generated signals with a hand-held source, after which analysts on Earth used arrival times and distances to estimate shallow structure. The 1971 preliminary science report gave compressional-wave velocities of about 104 meters per second in the surface layer and 299 meters per second beneath, estimating the local loose surface layer at about 8.5 meters thick.

These were preliminary interpretations of shallow structure at the landing site, not proof of the same layer thickness across the Moon. The passive seismometer could make coordinated observations with the Apollo 12 station about 181 kilometers away; both recorded the controlled impact of Apollo 14's lunar module ascent stage. Known artificial events helped researchers compare propagation characteristics, making surface equipment part of a continuing observation network.

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On February 6, the lunar module ascent stage lifted off and redocked with the orbiting command module, transferring crew and samples. At about 21:05 on February 9, the command module splashed down in the Pacific. The mission lasted approximately nine days from launch to completion, with only about 33½ hours spent on the lunar surface. Landing, leaving the Moon and returning to Earth each involved different engineering tasks.

The mission left returned samples, orbital photographs, geophysical measurements and records of surface operations. The preliminary science report explicitly stated that the samples and large quantities of data remained to be examined and interpretations could change with analysis. Later research on excursion scheduling also emphasized that scientific goals must be designed together with the time needed for equipment installation, travel, communication and crew coordination.

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