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Apollo 8 - the first general rehearsal for the moon landing

Lucky they didn't try to land the Apollo 8 lunar lander, because it could have crashed on the first interplanetary flight in history

The orbit of Apollo 8. Image: NASA
The orbit of Apollo 8. Image: NASA

After 17 manned launches, two in suborbital flights and 15 in flights around the Earth, the Apollo 8 launch reached the moon. The flight of Apollo 8 should be seen as the first manned interstellar journey. Apollo 8 was launched on December 21, 1968. Its pilots were James Lovell, Frank Burman and William Anders. Nitrogen infiltration into the oxygen tanks and bad weather the day before put the launch date in question. The repair of the malfunction and an improvement in the weather led to the launch of the spacecraft as planned.
The spacecraft's main mission was to circle the moon 10 times in an early stage and test for the future landing on the moon. An accompanying and necessary goal was to examine five possible landing areas. These were indeed the main tasks, but not the only ones. Additional tasks assigned to the spacecraft team were:

  • A. Test the tracking equipment on Earth.
  • B. to test the spacecraft's navigation equipment and long-distance communication equipment.
  • third. To photograph and conduct navigation experiments near the moon.

Due to the high risk involved in this flight, several escape routes were planned in the event of a malfunction at the launch site or near the Earth, and at the same time alternative targets were planned during its flight to the moon. The set of options were:

  • A. The astronauts could take an elevator down to the base of the launcher within 40 seconds and slide into an underground shelter made of concrete.
  • B. Sliding the Omega cable from the top of the launch tower to a point 800 meters from the base of the launcher, this descent also lasts 40 seconds.
  • third. In the event of a sudden explosion, during the ignition of the large engines in the first stage of the launcher, the astronauts could activate the escape tower located in the nose of the spacecraft to move away from the launcher.
  • d. After the launch, the spacecraft orbits the Earth twice and then the third stage engine is activated which directs it to fly towards the moon. In the event that this engine malfunctions, the astronauts can turn on the spacecraft's engine to move away from the third stage and save themselves from disaster.
  • God. If a malfunction occurs during the flight to the moon, the astronauts circle the earth in an orbit that is 100,000 km from the ground.
  • and. If a malfunction occurs when they are close to the moon, the astronauts can use the moon's gravity to return to Earth. When leaving the moon's gravity, the main engine and the small navigation engines are not used.
  • Those responsible for the flight also prepared for an 11-day stay instead of six if serious problems arose. Accordingly, the spacecraft was equipped with an appropriate amount of fuel, food and oxygen. Just as they cared about the lives of the astronauts, they also cared about their health. The astronauts were equipped with a kit of first aid equipment that included nose drops, eye drops, pills for every possible purpose from headache to infection, suitable equipment for treating toothaches and more. To maintain personal hygiene, the astronauts were equipped with brushes, toothpastes and paper napkins to remove sweat.
The first time the Earth's sunrise over the Moon was seen from the windows of the Apollo 8 spacecraft. Photo: NASA
The first time the Earth's sunrise over the Moon was seen from the windows of the Apollo 8 spacecraft. Photo: NASA

After two orbits of the Earth (the distances from the ground were 181-190 km) during which all the spacecraft's systems were tested, the third stage of the launcher was activated which accelerated the speed of the spacecraft to 39,000 km/h. A few minutes later, Borman fired several rockets that moved the spacecraft away from the third stage of the launcher which continued its flight after the spacecraft at a distance of less than one kilometer. It should be noted that as the spacecraft moved away from Earth, its connection with the tracking stations improved more and more.
On the second day of the flight, some small problems occurred and they are:

A. One of the life belts that the astronauts wear before landing in the ocean has inflated. The inflation may have been caused by the injection of compressed air adjacent to the life belts.
B. The spacecraft's windows were covered in fog. Two of the windows were covered with a thin layer and the third window was covered so that it became completely opaque. The other two windows remain clear.
third. Due to light entering the telescope it was difficult to identify stars.
d. Later, the astronauts felt cold and had to turn on the heating system.

11 hours after launch, one of the navigation engines was activated to correct the flight path. The engine ran perfectly. It took two seconds to increase the flight speed by 24 km/h.

Burman contracted a viral illness that lasted 24 hours (an infection that affects the digestive tract and passes within a day). At the beginning of the flight, Borman suffered from vomiting, diarrhea, chills and a headache. At first he tried to hide it from his doctors, but later decided to talk about it anyway. At first they thought he was suffering from Asian flu, but it turned out to be just a viral illness that lasted 24 hours. According to the instructions of the doctors, he took medicine and was relieved. His two flight mates also felt ill. If two or all three of them felt ill at the same time, the flight would be aborted.

That day, on December 23, after the television broadcast, the spacecraft passed the point where the Moon's gravitational pull exceeds that of the Earth. The correction of the route that day was canceled because it was found to be accurate. At the moment when the moon's gravity increased, the spacecraft's speed increased from 4,398 km/h to 9,300 km/h and it entered an orbit around it. Upon entering orbit around the moon, the spacecraft's engine was turned on for 4 minutes, slowing down its speed and putting it into an elliptical orbit, on the hidden side of the moon, so that contact with you was cut off until it entered the visible side. From the moment they entered the hidden side, 36 minutes of anxiety passed in the control center until they returned to the visible side. The spacecraft circled the moon 10 times in 20 hours. The first two orbits were elliptical and the spacecraft's distance from the ground was 119.8 - 312.8 km. The other eight laps were initially circular, the distance from the ground was 112.7 km and then reduced to 96 km. For the transition from an elliptical orbit to a circular orbit, the spacecraft's engine was turned on for 11 seconds.

During their flight around the moon, Lobel, in his transmission to the control center, described the landscape of the moon as seen from the spacecraft: "The craters are all rounded, their number is not small. Many look new, especially the round ones. They looked like meteorites or projectiles had hit there. The walls of the craters are graded from the rim of the craters to their bottom in 6-7 steps." As for the small craters, a dark spot can be seen in their center and fine white dust around it. The hidden side of the moon is all bumps and humps and is not suitable for landing spacecraft. The photographs of the moon showed an arid and gloomy landscape. Plains strewn with craters and potholes, plateaus strewn with rocks. Yeshimon is bigger than the Sahara desert. The researchers noticed slight downward deviations of the flight path. These deviations were probably caused by concentrations of water below the surface of 5 lunar days.

At the end of the tenth lap of the moon, the spacecraft's engine was activated and removed from its lunar orbit. The duration of leaving the track was 3 minutes and 20 seconds. At that time the connection with the earth was cut off and restored a quarter of an hour later. If the astronauts had not succeeded in breaking out of their orbit, the flight would have ended in disaster. During the departure from the lunar orbit, the spacecraft's flight speed was increased to 9,000 km/h and this speed kept increasing.

To increase the safety of the spacecraft and the astronauts, the spacecraft's engine was turned on for a longer period of time than planned. Thanks to this, the journey back is shortened from 65 hours to 58 hours. If they had entered the atmosphere at a smaller angle than planned the spacecraft would have burned up. If the entry into the atmosphere had been at a greater angle, the spacecraft would have been thrown into space and orbit the Earth in an irregular orbit that would have made it difficult to rescue the astronauts. The spacecraft entered the atmosphere with its nose pointed upwards to minimize friction. The astronauts themselves monitored the flight path. Finally, the spacecraft deployed its parachutes and landed in the Pacific Ocean 45 minutes before dawn after a journey of 6 days, 52 hours and XNUMX minutes. The astronauts landed wearing only their underwear and not their spacesuits.

With all the stress that accompanied this flight, the astronauts entered into a routine of daily work and this is evidenced by the preparation of food every day and especially on those days when Christmas is celebrated and the television broadcasts that took place once every 24 hours. In these broadcasts the astronauts showed the interior of the spaceship, the lunar landscape and the Earth as seen from afar. A big disappointment happened when a malfunction - teleobjective of the television camera that prevented the continuation of the photographing of the Earth. Instead of the earth they saw a bright and blurred spot. Usually the transmission was very clear and the ice crystals ejected from the exhaust nozzle of the spacecraft engine were also visible. The moon was photographed in the first, second and ninth cycles in color and black and white. A total of six black and white television broadcasts were conducted.
After the full data processing of the flight was received, it became clear that the navigation was so poor that if they had tried to land on the same flight - and indeed there were those who thought about this before the launch - the spacecraft would have missed the landing site by 8 km and might have crashed on its surface.

Additional chapters in the history of space exploration series:

The Apollo manned flight series

6 תגובות

  1. And on the other hand, there was a bridge that collapsed like a leaf blown in the wind. So don't present things as you like. In general, it seems that you find it difficult to accept the opinion of others, and maybe we are in retreat precisely because of people like you?

  2. The article reminds me of the story of the building of the Brooklyn Bridge. There, too, many disappeared and Rivling took large margins of safety. "Experts in the field", such as commenter Yaron, said that the bridge would not last 10 years. And here, it has been standing for over 130 years.

    In my opinion, the execution of Kennedy's space program was the pinnacle of human civilization. Since then, also thanks to people like Yaron, we are in constant decline.

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