Van Allen's belt and how Apollo overcame this challenge to the Moon (Part 1)

Recently, we have written an article Reviewing the theory, NASA explains how Apollo astronauts cross the Van Allen radiation belt?

Please read the 2-part synthesis section mainly from popular science magazines (Popular Science or PopSci, a quite prestigious scientific journal in the US with nearly 150 years of history) and NASA documents.

Van Allen radiation belt surrounds the Earth.

The Van Allen belts were found by one of America's leading space scientists at the time: James Van Allen . In the mid-1950s, Dr. James Van Allen began to explore the world of complex charged molecules outside the earth's atmosphere with rockets and rockoon rockets (small missiles launched from hot air balloons). on high). Initially his experiments were limited to radiation surrounding the planet from within the atmosphere. On the occasion of the International Year of Geophysical Year (International Geophysical Year-IGY, July 1, 1957 - December 31, 1958, an international event on exploring solar activity and earth science), Van Allen won the opportunity to perform higher-level experiments. The satellite Van Allen experimented with was the first satellite to orbit the US Earth, Explorer 1 was launched into the sky on January 31, 1958.

This time, the cosmic ray device on Explorer 1 recorded almost no radiation in the Van Allen area that predicted high radiation. Van Allen argues that low cosmic rays are inaccurate and the devices are saturated with molecules trapped in the earth's magnetic field. By March 1958, tools on Explorer 3 satellites confirmed Van Allen's hunch was correct. Discovering Van Allen belts became one of IGY's most outstanding scientific discoveries that year.

Van Allen belts and Explorer 1 satellites (Photo: NASA).

The Van Allen belts, the high radiation environment surrounding our green planet, are charged molecules trapped in the earth's magnetic field but have no energy to escape (the task of the magnetic field is to protect them. we lose the radiation deadly, and help this radiation not dissipate in space). The two belts are shaped like two interlocking donuts, located in different positions and the composition is also different: small inner donuts are mainly composed of protons above the earth 1,000. -6,000km; Large outer donuts (outer belt) including protons and electrons located 15-20 thousand kilometers from the earth. The radiation density of both belts is different, some radiation places are high, some are almost no radiation.

According to NASA, Van Allen radiation belts are the largest natural molecular accelerators in the Solar System , capable of making molecules move at 99% of the speed of light. In August 2012, NASA launched two satellites Van Allen A and Van Allen B to learn the natural acceleration mechanism of this belt.

Van Allen radiation belts are the largest natural molecular accelerators in the Solar System.(Photo: NASA).

Van Allen and Apollo

After discovering the Van Allen belts, the scientists clearly realized that they would be a challenge for traveling into space. The obvious solution is to limit missions within a safe height range within a small inner belt (starting at a height of 550km from the earth). However, not long after that, NASA thought about the plan to fly to the moon 384,400km away, which means bringing people through both small and large belts.

In the summer of 1960, the first solutions appeared. At a meeting in Washington, Robert O. Piland and Stanley C. White from NASA's space task force showed how to solve this big problem. Accordingly, it is not feasible to protect astronauts to overcome the high radiation environment of small belts, but with large belts, only a sufficient protection is required.

Half a year later, in January 1961, NASA was preparing a route to the moon by Apollo (though many months before it was officially announced). The Van Allen belt problem was again set."A standard model of the Van Allen belt can be used for all Apollo program orbital analysis" to become an emergency task of NASA's orbit analysis team. The team had to learn everything needed to draw the route that took the crew through this dangerous heavy radiation belt.

(Photo: Lego Ideas).

And so the discovery of Van Allen belts became one of many post-study research goals, when NASA brought Apollo from concept to public idea. Some of the results of this study have brought new suggestions. Typically, in July 1962, Van Allen himself proposed solutions for radiation and Apollo with the American Rocket Society (American Rocket Society). He said that belt protons would be a serious obstacle to expanding human missions. But we can "clean up" the belt with a nuclear bomb. Complementary matter will help the molecules have the extra energy needed to escape the Earth's magnetic field.

NASA has never used Van Allen's solution, but an Atomic Energy Commission experiment in 1962 made this radiation problem worse .

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