Survival after the explosion of Apollo 13

On April 11, 1970, astronauts Haise, Lovell, and Swigert were eating breakfast at the Kennedy Space Center to reserve energy for the Apollo 13 launch mission that day. No one knew that what was waiting for them was not an exciting moon landing, but a thrilling space adventure.

From left, astronauts Hayes, Lovell, and Swigert are having breakfast

At 13:13 pm Central Time, the Apollo 13 spacecraft, whose launch time had been repeatedly changed, was launched. At first, everything seemed to be in order. Although there were some minor problems, the mission went on normally.

Apollo 13 launches

On the 13th, 55:46 had passed since takeoff. The astronauts had just finished a 49-minute live broadcast and were preparing to return to the command module to rest. When the last astronaut, the lunar module pilot Haise, returned to the command module, a loud noise suddenly occurred. However, the astronauts did not immediately become alert because Haise often made such noises when opening valves before, so Lovell and Swigert thought it was another prank by Haise.

When they saw Hayes' innocent expression, they realized that something was not right. The ground control center did not know what happened to the spacecraft at this time. After a while, they heard a sentence as famous as Armstrong's "This is a big step for mankind". Commander Lovell sent back the message:

"Houston, we're in trouble."

Then, Lovell described the problems displayed by the system to the ground, and he found that the spacecraft was discharging something like gas into space. Later, Lovell found that the pressure gauge of the No. 2 liquid oxygen tank of the Apollo 13 service module had dropped to zero, and the No. 1 liquid oxygen tank was decreasing. This means that of the only two liquid oxygen tanks in the service module, the No. 2 liquid oxygen tank exploded and emptied the oxygen, and the No. 1 tank was leaking and was being emptied.

Apollo 13 service module perspective

The safety of the spacecraft and the astronauts was seriously threatened. This is because the liquid oxygen tank not only provides breathable oxygen for the astronauts, but also supplies fuel cells to generate electricity to maintain the normal operation of the command module and service module. At this time, two of the three hydrogen-oxygen fuel cells had stopped working and could not supply power to the command module normally.

25 seconds after the explosion, due to liquid oxygen leakage and insufficient power, the service module could not supply oxygen to the astronauts, and the command module could not maintain a suitable temperature. What's more serious is that the oxygen in the command module can only supply oxygen for another 15 minutes. Obviously, landing on the moon is impossible. How to save the lives of the astronauts and return safely became the focus of the astronauts and ground personnel.

Ground personnel are discussing

According to the situation at the time, the ground personnel quickly provided a rescue plan: they hoped to use the lunar module as a lifeboat, fly around the moon first to turn the spacecraft around, and then start the lunar module engine on the back of the moon to enter the orbit back to the earth. This would not only help the spacecraft speed up with the help of the moon's gravity, but also avoid using up all the propellant at once, reducing the possibility of damage to the spacecraft.

So, the three astronauts of Apollo 13 quickly entered the lunar module. In order to save electricity, oxygen and water, Swigert shut down the operating systems that might not be damaged before leaving the command module. In the lunar module, the astronauts also shut down part of the power of the lunar module, leaving only the power to support the life support system, communication, environmental control and necessary thrust systems. In this way, the power consumption was greatly reduced and could be maintained until returning to Earth.

Apollo 13 spacecraft perspective view

In order to get the spacecraft into lunar orbit and then change orbit to return orbit, the spacecraft must change orbit. At present, the only intact thing is the lunar module, which means that the astronauts can only use the lunar module's smaller descent engine to change the spacecraft's orbit.

Although there was no precedent for the lunar module to push the entire spacecraft in the mission, Apollo 9 used the lunar module to tow the command and service module for more than 6 minutes. Therefore, the ground personnel believed that it was possible to use the lunar module to change the spacecraft's orbit. At 61:28:43, Lovell, who had performed Apollo 9, started the lunar module's descent engine, and the spacecraft successfully entered the lunar orbit.

On April 14, Apollo 13 flew into the back of the moon. Due to the moon blocking the way, the astronauts lost radio communication with the ground. The ground personnel could only wait and hope. On the spacecraft, Swigert and Haise, who saw the moon for the first time, were excited to see the moon so close, and they kept taking pictures of the moon.

Keeler Crater on the Moon photographed by astronauts

At 18:49 on the 14th, the Apollo 13 spacecraft appeared on the other side of the moon and contacted the ground. A message came from the Apollo 13 lunar module Aquarius: "Houston, this is Aquarius, the scenery here is so beautiful."

Two hours later, Lovell and Haise started the lunar module engine, which lasted for 4 minutes and 26 seconds. The spacecraft successfully entered the orbit to return to Earth, and the return time was shortened by 9 hours. At this time, the three astronauts were exhausted and had to take turns to rest.

Lovell in the Lunar Module

However, the command module was very cold. As the temperature control system was turned off, the indoor temperature was only 3 degrees Celsius, and the astronauts could not sleep. Even if they entered the relatively warm lunar module to rest, it was still very uncomfortable. This caused the astronauts to be overly tired and even unable to complete their regular work.

The most difficult thing was that there was no hot water to wash the food, so the astronauts could only eat cold food. A few hours before returning to the atmosphere, the astronauts were exhausted and had to take appropriate amounts of stimulants to maintain their spirits. What was even more desperate was that 5 hours before returning, the problem of water shortage arose. The astronauts could only drink one-fifth of the normal amount of water a day, plus the water in the food to maintain, which caused them to be severely dehydrated. The entire astronaut crew lost 31.5 pounds, which was 50% more than other Apollo missions.

On the 16th, the astronauts vaguely saw the Earth and became excited. However, at this time, the Apollo 13 spacecraft deviated from the normal orbit of returning to the Earth and needed to determine the angle of entry into the Earth's atmosphere. If the angle was too small, the spacecraft would burn up in the atmosphere, otherwise, it would eject from the atmosphere and fly into the endless universe. Although the astronauts were very tired, they still calibrated the route together with the help of ground personnel.

On the 17th, the Apollo 13 spacecraft entered the re-entry orbit, and the ground control center instructed Swigert to jettison the damaged service module. The astronauts finally saw the damaged service module.

Damaged service module

After the astronauts followed the instructions and moved back to the command module to charge the battery, they abandoned the lunar module Aquarius, which they had relied on for survival in the past few days, with sadness and gratitude: "Goodbye, Aquarius. We thank you."

Lunar Module Aquarius

At 12:08, the Apollo 13 command module splashed down in the Pacific Ocean. "They won!" People all over the world were excited!

Apollo 13 command module splashes down in the Pacific Ocean

In the following content, we will tell you more knowledge and stories about the Apollo 13 mission, so stay tuned!

References/Accidents and Disasters in Manned Space Flight, The Story of Moon Exploration