Why cosmic radiation did not kill astronauts when flying to the moon

50 years ago one man made a littlesmall step, which turned out to be a big step for all mankind. We are talking, as you understand, about the famous landing of American astronauts on the moon. And recently, the controversy surrounding that mission (like the Apollo program itself) has flared up with a new force. And this is not about the fact that "there was no disembarkation and everything was filmed in the pavilion." New arguments tell us that during the mission to the moon, astronauts should have received a huge dose of cosmic radiation, which is impossible to survive. But is it?

What is cosmic radiation

No one is going to dispute the fact thatcosmic radiation does exist and the fact that its effect on living organisms is very difficult to call positive. The term “cosmic radiation” itself is quite extensive and is used to describe the energy that is emitted in the form of electromagnetic waves and / or other particles emitted by celestial bodies. However, not all of them are dangerous to humans. For example, people can perceive some form of electromagnetic radiation: visible light can (see for tautology) be seen, and infrared radiation (heat) can be felt.

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Meanwhile, other types of radiation suchlike radio waves, x-rays and gamma rays require special monitoring equipment. The most dangerous is ionizing radiation, and it is its effect that in most cases is called the very cosmic radiation.

Where does cosmic radiation come from

There are several sources in spaceionizing radiation. The sun continuously emits electromagnetic radiation at all wavelengths. Sometimes huge explosions on the sun's surface, known as flares on the sun, release a huge amount of x-rays and gamma rays into space. These phenomena are precisely the danger to astronauts and spacecraft equipment. Also, dangerous radiation can come from outside our solar system, but on Earth we are protected from most of this ionizing radiation. The earth’s strong magnetic field forms the magnetosphere (roughly speaking, a protective bubble), which acts as a kind of “shield” that blocks most of the dangerous radiation.

At the same time, cosmic radiation "does not fly away" back into space. It accumulates around our planet, forming the so-called Van Allen Belts (or radiation belts).

Van Allen Belts Device Diagram

How NASA solved the problem of organizing a mission to the moon

The short answer is no way. The fact is that in order to get to the moon, the spacecraft must move as quickly as possible and along the shortest distance. For “fly-around and maneuvering” there would not be enough time or fuel reserve. Thus, the program participants had to cross both the external and internal radiation belts.

NASA knew about the problem and therefore they neededsomething to do with the ship's trim for the astronauts. The sheathing should have been thin and light to provide protection. It was impossible to “burden” her too much. Therefore, minimal radiation protection with metal plates was added to the structure. Moreover, theoretical models of the radiation belts, developed on the eve of the Apollo flights, showed that passing through them would not pose a significant threat to the cosmonauts' health.

But that is not all. To get to the moon and return home safely, the Apollo astronauts had to not only cross the Van Allen belts, but also a huge distance between the Earth and the Moon. By the time the flight took about three days in each direction. Mission members also had to work safely in orbit around the moon and on the lunar surface. During the Apollo missions, the spacecraft most of the time was outside the Earth’s protective magnetosphere. Thus, the Apollo crews were vulnerable to solar flares and to the flow of radiation from outside our solar system.

Why are astronauts alive?

We can say that NASA was lucky, because timemission coincided with the so-called "solar cycle". This is a period of growth and decline in activity, which occurs approximately every 11 years. At the time of the launch of the devices, there was just a period of decline. However, if the space agency delayed the program, everything could have ended differently. For example, in August 1972, between the return of Apollo 16 to Earth and the launch of Apollo 17, a period of increasing solar activity began. And if at this time the astronauts were on their way to the Moon, they would receive a huge dose of cosmic radiation. But this, fortunately, did not happen.

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