A Faulty Switch Tried to Abort the Moon Landing

1. Mission Launch

Apollo 14 launched from Kennedy Space Center on January 31, 1971, carrying Commander Alan Shepard, Command Module Pilot Stuart Roosa, and Lunar Module Pilot Edgar Mitchell. The flight marked the eighth crewed mission in the Apollo program and the first lunar landing following the Apollo 13 accident. Post-accident modifications to the spacecraft aimed to ensure safety and reliability during the journey. The crew traveled toward a planned landing site in the rugged lunar highlands.

The spacecraft entered lunar orbit after a successful service propulsion firing.

2. Descent Preparation

On February 5, 1971, Shepard and Mitchell boarded the Lunar Module Antares and separated from the Command and Service Module Kitty Hawk. Roosa remained in lunar orbit aboard Kitty Hawk to perform scientific experiments and photograph potential landing sites. Antares was maneuvered into a lower orbit to increase hover time during the descent over rough terrain. Shortly after separation, two critical hardware malfunctions threatened the success of the mission.

The lunar module began its powered descent toward the Fra Mauro formation.

3. Faulty Abort Switch

During descent preparation, the lunar module computer began receiving an erroneous ABORT signal from a faulty switch. Engineers suspected a tiny stray ball of solder had floated between the switch contacts and closed the circuit. Initial attempts to clear the signal by tapping on the instrument panel worked only briefly. If unaddressed, the computer would interpret the signal as real during engine firing and automatically separate the ascent stage.

Mission Control and software teams scrambled to develop an emergency workaround.

4. Software Workaround

Because the guidance computer software was hard-wired and could not be updated from the ground, MIT software specialists devised a novel workaround. The fix instructed the computer system to ignore incoming automated abort signals by making it appear that an abort had already occurred. Mitchell successfully entered the software patch into the guidance computer minutes before planned ignition. The workaround successfully prevented an unwanted automated abort sequence.

The crew retained manual control over the descent engine operations.

5. Landing Radar Failure

A second major malfunction occurred during powered descent when the lunar module landing radar failed to lock automatically onto the lunar surface. The missing radar data deprived the navigation computer of vital altitude and vertical descent speed measurements. Mission rules dictated an abort if the landing radar was non-functional at an altitude of 10,000 feet. The astronauts quickly cycled the landing radar circuit breaker to reset the unit.

The radar successfully acquired a surface signal near 22,000 feet altitude.

6. Fra Mauro Landing

With the landing radar operational, Shepard manually steered Antares to a successful landing within the Fra Mauro formation. The touchdown location was closer to the intended target than any previous lunar landing mission. The crew deployed equipment and prepared for their first surface extravehicular activity. Geological investigations aimed to collect ejecta material from the ancient impact event that formed Mare Imbrium.

The astronauts initiated their scheduled moonwalk operations on the surface.

7. Surface Exploration

During two surface excursions, Shepard and Mitchell collected 94 pounds of lunar rocks and deployed scientific experiments. Their trek toward the rim of Cone crater proved physically exhausting due to undulating terrain and optical misjudgments of distance. Photographic analysis later confirmed that they came within 20 meters of the crater rim. Shepard also performed a planned golf demonstration using a makeshift club head attached to a sampling tool handle.

The crew completed their surface tasks and re-entered the lunar module.

8. Return and Splashdown

Antares successfully lifted off from the lunar surface on February 6, 1971, and completed a direct rendezvous and docking with Kitty Hawk. After transferring the lunar samples and equipment, the crew jettisoned the ascent stage to impact the Moon. The spacecraft executed a trans-earth injection burn to begin the return journey. Kitty Hawk splashed down safely in the South Pacific Ocean on February 9, 1971.

Recovery helicopters transported the astronauts to the USS New Orleans.

9. Quarantine Protocols

Following recovery, the crew was flown to a Mobile Quarantine Facility and transferred to the Lunar Receiving Laboratory in Houston. The Apollo 14 astronauts were the final lunar explorers subjected to mandatory biological quarantine upon returning from the Moon. They remained in isolation until their release on February 27, 1971. Medical evaluations confirmed the crew remained healthy throughout the quarantine period.

The post-flight quarantine procedures concluded without incident.

10. Mission Legacy

Shepard, Mitchell and Roosa returned to Earth on February 9, 1971, with the collected lunar material. The abort-switch workaround had allowed the landing attempt to proceed, and the landing-radar problem had also been addressed during descent. The flight ended with recovery in the Pacific and a later quarantine release, rather than the unwanted automated abort the crew had worked to prevent.

The crew returned with samples after completing the landing.

Sources

• Original narrative adaptation — CC BY-SA 4.0
• Wikipedia contributors — Apollo 14 (CC BY-SA 4.0)
• Apollo 14 Command and Service Module (CSM)