Author Dragon Sunflower
The United States has the most manned lunar landings in the world and is by far the only country to have successfully landed on the moon. As early as the end of the 1960s, the United States proposed the Apollo series of plans, and in 1969, three astronauts were sent to the moon for the first time, kicking off the prelude to the human landing on the moon. After the successful landing of Apollo 11 on the moon, NASA was in a hurry to prepare for the launch of Apollo 12, which shocked the human space community.
The second manned lunar landing in the United States was also successful, but the implementation of the third plan was unexpected. Apollo 13 was launched in 1970 and carried three astronauts, Jim Lowell, Jack Swegert and Fred Hayes. Apollo 13 was successfully launched and entered a predetermined orbit in space. On the third day, the three astronauts received instructions from the ground control center to stir some liquid oxygen tanks, and the astronauts followed the instructions to do things, and the accident happened.
What kind of dangers were the three astronauts facing at the time?
It is understood that the Apollo 13 spacecraft is divided into three stages, the lunar module, the command module and the service module, while the liquid oxygen tank is placed in the service module. After receiving instructions from the ground control center, one of the astronauts went to the service module and pressed the button, but when the astronauts were ready to leave, the liquid oxygen tank exploded. At that time, Apollo 13 was on its way to the lunar orbit, and such an event already meant that it was impossible to land on the lunar surface normally, and even whether it could safely return to the surface became a problem.
After the liquid oxygen tank exploded, the lives of the three astronauts were greatly threatened. The first is that normal oxygen supply cannot be carried out in the cabin after the explosion of the oxygen tank, which will affect the awareness and judgment of the astronauts. Second, the energy power system of the entire spacecraft is closely related to the liquid oxygen tank. It is understood that the power supply for Apollo 13 is three large fuel cells, and their normal operation requires the participation of liquid hydrogen and liquid oxygen, and the explosion of the liquid oxygen tank means that the power system on the spacecraft is paralyzed.
After receiving the return plan from the ground control center, the three astronauts must also save power on the spacecraft to ensure that they can follow the preset steps, otherwise they will remain in space forever. This led to a gradual decrease in the concentration of oxygen in the cabin, the temperature system stopped working, and the three astronauts were once trapped in an environment of only 4 degrees Celsius, and the dangerous situation they faced could be described as very critical.
How did ground personnel and astronauts accomplish this great deliverance?
From the launch of Apollo 13 to the launch of space, NASA's ground control center monitors and tracks in real time. After the Apollo 13 accident, ground personnel reacted quickly and made plans to return to Earth. After the expert group's seminar, they finally asked the astronauts to control the spacecraft according to the instructions of the ground personnel, first let the spacecraft fly to the surface of the moon, and then use the moon's gravity to enter the return orbit.
After receiving the ground command, the three astronauts immediately began to divide their work, Lowell and Hayes entered the lunar module first, while Swegert remained alone in the command module, because his job was to transport the only remaining oxygen in the service module to the storage equipment in the command module, and then connect the emergency battery pack placed in the command module to re-supply the spacecraft with power. The other two astronauts stayed in the lunar module waiting for ground instructions in order to seize the opportunity to enter the orbit around the moon.
When the Apollo 13 spacecraft was about 218 kilometers from the moon, Lowell received instructions to activate the landing engine of the lunar module. After flying in this state for about 21 hours, Hayes received the command to activate the ascending engine of the lunar module, which allowed the spacecraft to smoothly enter the return orbit. But the return work is not over, after entering the atmosphere, the three astronauts received instructions to start the explosion bolt in the command module, so that the command module and the lunar module were separated.
In the end, the command module where the three astronauts were located successfully fell into the Atlantic Ocean and was successfully rescued by the sea rescue team. Although the mission to the moon failed, the three astronauts were able to safely return to Earth after the explosion accident, which is a fortunate misfortune. The event also became the greatest rescue operation in the history of human spaceflight, and this success was inseparable from the careful planning of the ground control center and the level at which astronauts in danger remained calm and played a professional role in dealing with risks.
What caused the accident?
After the accident, NASA set up a special investigation team to investigate the cause of the accident. In fact, the causes of this accident are both NASA's own institutional problems and the operational problems of technical employees. It is understood that the liquid oxygen tank used by Apollo 13 is actually "second-hand goods", which was originally the "first-hand goods" of Apollo 10, but it fell during the test of Apollo 10, and then it was set aside.
In the process of research and development of Apollo 13, engineers remembered the shelved liquid oxygen tank, through simple external testing found that it can still be used, so it was installed in the service cabin of Apollo 13, but after the investigation found that a line inside the second-hand liquid oxygen tank has been damaged, as long as the outside world is slightly applied to a little mechanical external force, it is easy to cause an explosion, which is equivalent to installing an untime bomb on Apollo 13, and the bomb eventually exploded.
In addition, investigators found that this problem could have been avoided in equipment inspections before the launch of Apollo 13, but it was not taken seriously. A technical employee had already found that it could not eliminate oxygen normally when testing the liquid oxygen tank, so he reported the situation to his superiors and only repaired the liquid oxygen tank, but did not replace the liquid oxygen tank, which once again planted an untime bomb for Apollo 13.
In contrast, the astronauts on the Space Shuttle Challenger were less fortunate
After the Apollo 13 explosion, people praised NASA and the astronauts' ability to respond, but the "Challenger space shuttle air explosion" in 1986 made the world see the risks of spaceflight again. Unlike the Apollo 13 accident, Challenger exploded shortly after liftoff, not even flying out of Earth, and all the astronauts on board were killed, and the accident also taught NASA a painful lesson.
At the same time, these accidents in the field of space are also lessons for us, rocket launches such a huge project, every detail must be put in place, as long as one detail is a problem, enough to lead to the failure of the entire plan, resulting in the sacrifice of astronauts.