Apollo 13 mission

In April 1970, the U.S. "Apollo 13" spacecraft was carrying out the third lunar landing plan, when a sudden explosion occurred, and the pilot Lowell looked out of the window and found that some mysterious substances in the tail of the spacecraft were leaking out.

After the explosion, the spacecraft's commander, Swigget, quickly reported to the launch center, and then ground controllers discovered that it was the No. 2 oxygen tank in the spacecraft's service module that had exploded.

The mysterious gaseous substances that leak out are the oxygen that astronauts rely on to survive. At this time, the spacecraft is 320,000 kilometers away from Earth.

The leakage of oxygen tanks not only directly threatens the survival of astronauts, but also triggers a "lack of electricity" crisis, because the batteries on the spacecraft mainly rely on the reaction of liquid oxygen and liquid hydrogen to generate electrical energy, when the liquid oxygen supply is insufficient, the fuel cell can not continue to work, and the spacecraft faces the threat of "shutdown" at any time.

At the same time, the water produced by the fuel cell is also the source of drinking water for astronauts, and after the fuel cell stops working, the spacecraft enters the dilemma of water shortage at the same time.

At this time, the voltage reading of the spacecraft's B bus appeared abnormal, the voltage reading began to drop, and then, two fuel cells failed, the No. 1 oxygen tank was affected by the explosion, and the air pressure was constantly decreasing.

As more and more oxygen drifted into space, ground controllers issued instructions to the astronauts: "Turn off the valve of Fuel Cell 3." The astronaut who received the order was half cold in his heart, and turning off the valve meant giving up the moon landing.

However, they soon realized that it was a fool's dream not to say that they could return to Earth without saying that they could go to the moon. Because at this time, the oxygen in the command chamber is only enough for 3 people to breathe for 15 minutes.

They had to find a way to transfer to the lunar module, but fortunately, when the valve of the No. 3 fuel cell was closed, there was no accident, and the next battery was successfully reserved for them.

But to start the lunar module, it is difficult, they must enter the coordinate data into the lunar module before the power of the command module is exhausted, so that the lunar module will not lose its way in space.

The lunar module has independent power supply, oxygen supply equipment, and powered engines, and although the shell of the lunar module is very thin, it has become a lifesaver for the three astronauts.

After intense calculations, astronaut Hayes entered complex numbers into the lunar module's computer. At that moment, even if a number is wrong, they will die in an instant.

Fortunately, just before the oxygen in the command module was about to run out, the function of the lunar module was activated in time. After being transferred to the lunar module, Lowell tried to fly the lunar module, but found that the lunar module kept bumping and did not listen to the call.

It turned out that the lunar module was dragging the command module, top-heavy, and there was no way to control it, and Lowell used all his strength to stabilize the spacecraft. At this time, they are still facing the problem of lack of electricity and water.

They only have enough electricity for 2 days, and it takes at least 3 days to return to Earth. The ground control center adjusted the flight route for them to shorten it by 12 hours, and when approaching the dark side of the moon, Lowell activated the automatic driving mode, ignited the lunar module, started the engine, and accelerated the spacecraft by 40%.

In order to save power, they had to shut down the navigation system and computers, reduce the power consumption to 12 amperes, and enter the "super power saving mode", leaving only the radio and a small fan to work.

At this time, the astronauts faced another big problem, the design of the lunar module for only 2 people, equipped with a small air filter, can not deal with the carbon dioxide emitted by 3 astronauts, and now the concentration of carbon dioxide is rising, they are in danger of poisoning at any time.

When they brought the carbon dioxide filter in the command module over, they found that the filter in the command module was square, while the filter in the lunar module was round and could not be installed at all. In an emergency, they can only modify the filter with tape, cardboard and other tools under the instructions of the ground control center.

After modification, the carbon dioxide concentration was reduced. Personnel who have been following the spacecraft's trajectory have found that the spacecraft has somehow deviated from its orbit. At this point, you need to adjust the flight angle to enter the "corridor" to return to Earth.

If the angle of entering the "corridor" atmosphere is too large, it will cause the spacecraft to catch fire, and the spacecraft with too small an angle will be easily ejected and flew out.

Since the autopilot system in the lunar module has been turned off, the three astronauts need to work together to enter the "corridor" by manually adjusting the spacecraft. When the spacecraft enter earth orbit through the "corridor", they must return to the command module and abandon the service module and lunar module to successfully cross the atmosphere.

Because the spacecraft produces high temperatures when it travels through the atmosphere, only the command module is equipped with a heat shield. At the command of the ground control center, the astronauts used a circuit breaker, allowed the command module to complete the charging, and restarted the command module.

Now astronauts face the final hurdle, that is, when the command module enters the atmosphere, friction will generate high temperature negative ions around the capsule, causing the radio to disappear and there is no communication signal for 3 minutes.

What is even more frightening is that the speed of the command module is 40,000 kilometers per hour, and once the heat shield cracks, the 3 astronauts will vaporize in an instant.

The astronauts knew they might die, and Swegt even left a last word to the ground control center: "All of us thank you for all that you have done for us." ”

The god of luck took care of them again, and after the signal disappeared for 4 minutes and 28 seconds, the people in the control center saw the command module again, they safely crossed the atmosphere, and 3 red and white parachutes landed safely in the South Pacific with the command module.

In a later investigation, it was found that the No. 2 oxygen tank that caused the explosion at that time was actually a second-hand product. It was originally installed on Apollo 10, but was accidentally damaged during installation. The oxygen tank was then repaired and installed on the Apollo 13 spacecraft.

This lunar exploration is known as the "most successful failure", "epic" space rescue, accumulating a lot of enlightenment and reference for human space history, and even more meaningful and valuable than a successful moon landing.

Although the exploration of space is full of dangers, the journey of human beings in the sea of stars has never stopped!