Apollo 13 astronauts had no inkling that their spacecraft was leaking; yet even minor issues could prove fatal as they transitioned between modules Odyssey and Aquarius.
Problem was, their oxygen tank number two had exploded, rendering landing on the moon impossible.
1. Oxygen Tank Explosion
At 56 hours into their mission, a problem with the second oxygen tank on board the spacecraft caused it to explode. During a “cryo stir” procedure – designed to mix liquid oxygen so it wouldn’t stratify – power fans were turned on within the tank for this operation and exposed wiring shorted out, sparking ignition of its teflon insulation which rapidly heated up, increasing pressure, eventually leading to its demise and an explosive leak that quickly depleted other systems in its path.
The crew had to adapt quickly and improvise, using their Lunar Module as a temporary source of power, guidance, and life support until their damaged Command and Service Module (CM) could be repaired and readied for reentry.
Accident investigators determined the source of the mis-rated heater to be on an oxygen tank’s electrical panel. Although intended to run at 28 volts, its voltage had been switched up during one of Apollo 13 launch pad’s final tests to 65. As a result, thermostatic switches in their heating systems opened, leading to insulation wires conducting and sparking explosions.
This incident demonstrated the necessity of contingency planning and designing spacecraft to handle unexpected events, which in turn helped Apollo 13 become a success despite all odds. Furthermore, this event helped bolster public support for the program as well as renew its commitment to safety within NASA – testaments to their strength that their crew was able to overcome such extreme odds.
2. Fuel Cell Explosion
NASA’s Apollo program marked a monumental undertaking and represented humanity’s first attempt to land humans on another celestial body, marking humankind’s inaugural lunar landing mission. To make this dream a reality required a monumental effort involving several generations of astronauts as well as one of the largest launch vehicles ever used to get underway. Mercury tested one-person crews’ ability to survive and work in space before Gemini tested maneuvers and components necessary for landing on the moon; finally Apollo launched in 1961 and ended six lunar landing missions throughout its lifespan between 1961 and 1972 with six successful lunar landing missions!
The spacecraft was composed of three parts, the command module (CM), which served as living quarters for astronauts; service module (SM), which contained propulsion and support systems; and lunar module, which would take astronauts on round trips from Earth to Moon before docking with the command module at its conclusion.
Astronauts aboard each flight donned protective suits designed to shield them from cosmic radiation and other environmental risks, and were transported aboard spacecraft that fit roughly as many passengers as a car – taking seven days or so to circle the moon and return home again.
While unmanned Apollo development missions were launched in 1966, crewed flights were delayed by a fire that broke out during an Apollo 1 test flight on January 27, 1967 and killed astronauts Virgil Grissom, Edward White, and Roger Chaffee. When finally launched on its accelerated schedule to demonstrate US superiority over Soviet rivalry.
3. Electrical Problems
Apollo 13’s crew managed to overcome many difficulties and return safely, thanks to their teamwork, American spirit, ingenuity and determination. A key lesson from their incredible mission was the importance of remaining clear about your end-goal during times of uncertainty; especially relevant when working on high-pressure projects.
Armstrong, Aldrin and Collins were in a spacecraft known as a Command/Service Module powered by 28 volts of direct current; astronauts relied on two tanks inside for oxygen consumption. When their craft separated from its host spacecraft (LM), however, the astronauts no longer had access to these oxygen supplies and needed alternative means of breathing.
Due to this, the LM began losing oxygen at an unmanageable pace for its crew to utilize, while also losing electrical power, water resources and access to its propulsion system.
An investigation revealed that during maintenance work on the oxygen tank, an accident exposed a wire in its interior that resulted in shorting and sparking, sparking flames which ignited hydrogen stored within it and burned through oxygen lines – igniting an electrical fire which was impossible to extinguish.
Grumman and MSC held a conference to define the Lunar Module’s electrical power system (EPS), during which Grumman representatives conducted an analysis of its primary lunar mission’s requirements, such as maximum power usage rates and weight and reliability requirements for fuel cells and batteries. Initially, it was intended that this mission be powered solely by fuel cells; however, due to Grumman and MSC determining that total energy requirements of the mission exceeded what fuel cells could supply, and switched to all-battery configuration instead.
4. Communication Problems
Communication is essential to any space mission’s success and this was ensured during Apollo through two main components: the Command Module and Lunar Module. The former served as a three person capsule carrying astronauts between Earth and the moon while returning them back again, while Lunar Module would land on lunar surface before taking back its crew back up into orbiting Command Module.
As the Lunar Module Eagle detached from Columbia and started its descent onto the moon, residual pressure caused by Newtonian physics caused it to gain extra boost, enough to slightly alter its course and provide Armstrong and Aldrin with numerous terrifying challenges as they navigated their descent onto its surface.
One of the most crucial moments was when the 1202 alarm from Apollo Guidance Computer went off, signalling it had overloaded its core processing system and certain mission critical programs would need to be prioritized over others; flight controllers knew this could affect mission success; therefore they decided to proceed with their mission regardless.
Another issue arose when the landing radar and primary guidance and navigation system differed on their altitude over the moon’s surface. It was determined that this difference was caused by an anomaly in the attitude control system as well as multipath interference resulting from this.
The crew managed to overcome these difficulties through training, rehearsal and intensive pre-mission simulations. Furthermore, they could rely on one team member from mission control known as CAPCOM; an astronaut trained specifically for stress-inducing situations who provided positive yet supportive messages aimed at keeping everyone calm in an intense situation.
5. Landing
As Apollo 13 crewmembers prepared their lunar module to land, they faced several tense moments that nearly derailed their mission. First, their computer gave incorrect landing instructions during landing sequence. Furthermore, their lunar module (LM) appeared to be heading toward craters with truck-sized boulders instead of its anticipated smooth plain predicted in orbital maps. Aldrin took semi-manual control to avoid these rocks before landing safely at Little West with 25 seconds left worth of fuel remaining.
When the astronauts suited up for their moonwalk, they inadvertently knocked off a circuit breaker that controlled power running to their ascent engine–the very engine designed to launch them off of the Moon! When this occurred, alarms went off indicating that Apollo Guidance Computer’s core processing system had become overwhelmed – however fortunately this computer had been designed so mission critical programs would take priority over less critical ones.
At some point, it became evident that a defective circuit breaker was responsible for 1202 program alarms – this meant oxygen was being lost at an alarmingly fast rate – something the astronauts knew was bad news but weren’t sure what steps to take to address.
Aquarius was their backup spacecraft intended to keep Lovell, Swigert and Haise alive for up to 90 hours until Odyssey could return and reenter Earth’s atmosphere for reentry. To conserve power for reentry they worked hard at starting Aquarius up as quickly as possible while turning off nonessential systems on Odyssey for power conservation purposes.