Apollo 13 is one of the most significant missions in the history of space exploration. It was the seventh manned mission in the Apollo program and was launched on April 11, 1970, from the Kennedy Space Center in Florida. The mission was supposed to land on the moon and explore its surface, but an explosion in one of the oxygen tanks caused severe damage to the spacecraft. This incident led to a crisis situation which threatened the lives of the astronauts onboard.
Objectives of the Apollo 13 Mission
The objectives of the Apollo 13 mission were multi-fold. The primary goal was to make a third landing on the moon and conduct scientific experiments on its surface. The mission was also aimed at developing and improving the spacecraft’s propulsion system, life-support, and communication systems. Another objective was to test new and advanced technologies that could be used in future space missions.
The Apollo 13 mission was also part of the Cold War Space Race between the United States and the Soviet Union. The United States was determined to demonstrate its technological superiority over the Soviet Union, which had already achieved significant milestones in space exploration, such as launching the first artificial satellite (Sputnik 1) in 1957, and sending the first human (Yuri Gagarin) into space in 1961. Therefore, the Apollo 13 mission was not just a scientific exploration mission but also a political one with important implications for the global perception of the United States as a superpower.
What Went Wrong in the Apollo 13 Mission?
The Apollo 13 mission ran into unexpected problems when an explosion occurred in one of the oxygen tanks in the Service Module at approximately 56 hours 30 minutes of the flight. The explosion caused significant damage to the spacecraft, and the crew was in danger of being killed in space. The oxygen tank was designed to supply breathing oxygen as well as powering the fuel cells that generate electricity. When the explosion occurred, it caused a pressure dump, which resulted in a sudden loss of the majority of the oxygen supply to the Command Service Module (CSM) and landed them in a situation they could not have anticipated. The landing module containing the astronauts had to be manoeuvred back to earth with minimal use of power provided by the lander's engines.
The Apollo 13 spacecraft was also losing power because it could not rely on the fuel cells, as they were badly damaged during the explosion. The spacecraft and the Command Service Module of Apollo 13 were designed with redundant systems to ensure that any failure would not be catastrophic. However, in this case, the explosion had damaged both the primary and secondary backup systems, which made the situation even more critical.
The explosion damaged the oxygen tank and the systems that used it, resulting in a loss of power, and the spacecraft began to drift away from the planned trajectory. Moreover, the explosion also damaged the heat shield, which exposed the crew to the dangerous solar radiation during their re-entry to earth's atmosphere if they survived the ordeal.
How NASA Managed to Bring the Apollo 13 Crew Back Safely?
NASA had to make significant changes to its operational plans to save the crew onboard Apollo 13 after the explosion. The primary concern of NASA was the safety of the crew, and it acted quickly and decisively to ensure that the crew came back alive. NASA assembled a team of experts to evaluate the situation and come up with a plan to bring the spacecraft and the crew back safely.
The first step taken by NASA was to assess the damage to the spacecraft and determine the critical systems that were necessary to bring the spacecraft back safely. Next, they focused on conserving the power and oxygen supply to ensure that they lasted the entire journey back to earth. They turned off all non-essential systems and modules to conserve power.
NASA also worked on improvising and creating a makeshift air filter using duct tape, which allowed the crew to breathe without running out of oxygen until they safely arrived back on earth. The NASA team improvised an oxygen transfer system with sufficient pressure to be able to sustain eleven minutes of flying without the usual flow rate.
To save power, they shut down the computer systems and used a manual navigation system where the crew had to calculate their entry angle by hand, pointing to the position of stars. The final step was to improvise a new re-entry strategy as the spacecraft was not operating under the preferred criteria. NASA used a new return trajectory that allowed the spacecraft to enter the earth's atmosphere safely.
NASA’s crew and management deselected the usual landing site, Pacific Ocean, and instead headed for the closer and smaller land mass in the South Atlantic. The team studied the weather patterns to ensure that the crew landed in a calm sea surface condition. The crew and command module craft braked through the atmosphere with a slight entry angle of 7.19 degrees instead of the standard angle of 5.5 degrees to reduce the amount of energy they will absorb during descent and to make sure the craft flew as high as possible to slow down its descent before it hit to the water.
The successful return of the Apollo 13 crew to earth was a remarkable achievement and a testament to NASA’s dedication and expertise. The NASA engineering team and the Apollo 13 crew worked together with extraordinary ambition, improvisation, and ingenuity to overcome the challenges they encountered.
Impact of the Apollo 13 Mission
The Apollo 13 mission had a significant impact on space exploration and NASA staff. The incident made NASA aware of the need for a more stringent safety protocol while preventing inadequate oversight of seemingly small problems. The incident served as a significant wake-up call for NASA, which previously operated with a more lax attitude towards safety issues.
The Apollo 13 mission highlighted the fragility and complexity of spacecraft and demonstrated the importance of redundancy and robust engineering. This experience led to NASA rethinking its previous safety procedures and implementing changes that lead to safer and more efficient spaceflight.
