How did Apollo deal with the Van Allen radiation belts ?

One of the most hotly contested procedures during the Apollo missions was how NASA dealt with the issue of Van Allen belts, the naturally-occurring belts of radiation that's suround the earth both on the journey to the moon and also returning from it. To some this just proves the point that NASA never went to the moon because they contest that if the crew went through the Van Allen belts they would have received a lethal dose of radiation and died during or shortly afterwards but as we know that didn't happen so how did NASA achieve this. Mention the word "radiation" and most people think of x-ray,s the atom bomb Hiroshima, Chernobyl and therefore associated with bad things. Yes, you do need thick lead shielding to protect against high-intensity x-rays but the radiation in the Van Allen belts is not x-rays, it's charged particles. There are two main types of radiation the first is electromagnetic waves this covers everything from radio waves through microwaves, infrared which we feel is heat, visible light on through ultraviolet light onto x-rays to gamma rays, that is the electromagnetic spectrum. The second type of radiation is charged particles, these are the component parts of atoms such as protons, neutrons and electrons which had been broken apart by nuclear reactions or extreme heat in the Sun. These particles flow out from the Sun as the solar wind and because they have a positive or negative electric charge they react with the Earth's magnetic field. Some are attracted to the north and south poles where they enter the atmosphere and react with the air to create the northern and southern lights others are captured into the bands of magnetic fields around the earth where they form the Van Allen belts. These consist of an inner and outer belt and a temporary third belt which appears when the Sun has large solar flares. These bands extend from between 1000 and 60,000 miles above the earth surface with the most active areas centered around the equatorial area of the earth but thin out near the poles. This type of charge particle radiation is also known as ionizing radiation which means that it has enough energy to knock electrons from atoms or molecules that make up spacecraft and the crew inside, which can cause tissue damage if there is a high enough exposure for long enough. The main types of ionizing particles in the Van Allen belts are high-energy protons and electrons. The protons can be stopped by light materials such as the aluminium skin of craft and also the epoxy resin Heat shield. Electrons which are also known as beta particles can penetrate several inches into living tissue but because they're very small they don't tend to do much damage, they can also be blocked by materials like polyethylene which contain a lot of hydrogen. The hydrogen atoms are very light and absorb the beta particles as well as the fibrous insulation material that was fitted between the inner and outer hulls of command module should also have been a good shoot against them. One problem is that when beta particles interact with large atoms like late they give off secondary x-rays and this is called the bremsstrahlung effect, so the thick lead shielding but some people think is needed to protect the crew against x-rays would ironically make the problem worse by creating more xrays whereas the lighter metals like stainless steel and aluminium of command module would create less x-rays and even then some of the x-rays would be absorbed by the inner hull. So whilst we can shield against the radiation to a degree provided it's not too strong, there are other things have been NASA engineers and the mission planners knew about and one of these was where the thickest and most lethal parts of Van Allen belts were and also how the human body reacts to radiation. The effects of radiation are cumulative which means the longer exposed to it the more damage it causes. Within reason a short exposure to high levels of radiation is better tolerated by the body as it has time to repair the damage afterwards. Long exposures to low levels of radiation caused more problems because the body has to try and repair itself and contend with a continual damage while it's doing so. If you spent an extended period within the Van Allen belts then the effects would be lethal but the Apollo Crews only spent about six hours in total. around three and a half hours going two and a half hours returning several days later, effectively to short bursts separated by a rest period. More importantly the course which each of the Apollo craft took avoided the most lethal parts of the inner belt completely and they only went through the thinnest part of the outer belt. All the astronauts wore dosimeters to measure their personal radiation exposure levels during the flight and reported results back to NASA at regular intervals. In total the amount of radiation at the Apollo Crews received during their flights to and from the moon from high-energy protons electrons and x-rays from the bremsstrahlung effect was much less than that of the yearly allowed dose for someone working the nuclear industry and regularly dealing with radioactive materials. In the end a simple answer to why Van Allen radiation belts were not the killer issue that some people think it was and how the Apollo missions cut a radiation exposure from the cruise to between just 1% and 5% of what it could have been is because the Apollo missions didn't need to go straight through the Van Allen belts is because they basically flew around the most deadly areas and we're not in the less dangerous areas for long enough for it to be a showstopper. This remains true today as it was for any future missions, why go through it, when you can just go around it. Thanks for watching and I hope you found it interesting informative if you did let me know in comments below and as always please subscribe, rate and share. We also have other videos you may find interesting on the click more videos link above now showing. So it's goodbye for me and I hope you drop by again soon :-)

Channel: Curious Droid

Views: 1,980,323

Rating: 4.6941032 out of 5

Keywords: van allen radiation belts, van allen, radiation, x-rays, xrays, x-ray, proton, apollo, apollo radiation, apollo radiation dose, electron, beta particle, charged particals, moon hoax, electromagentic radiation, radiation risk, radiation dose, curious-droid.com, nasa, space, moon, van allen radiation belt, moon landing hoax, van allen belts, nasa hoax, hoax, apollo hoax, james van allen (academic), apollo missions, moon landing, charged particle, bremsstrahlung effect, paul shillito

Id: lNiscigIgBc

Length: 6min 34sec (394 seconds)

Published: Sun Jan 08 2017

Reddit Comments

[u/pquade]

http://www.braeunig.us/apollo/apollo11-TLI.htm

On the page are links to orbital elements.

[u/Scholesie09]

An equatorial flight path to the moon would be no good anyway since the moon is at an inclination of several degrees (18.28 - 28.58) relative to the earth's equator

[u/ashmain675]

If the apollo crafts went on an equatorial flight path the the astronauts cancer would have cancer

[u/Gaiiden]

Kerbalism has magnetic fields and radiation belt mechanic for all planets

[u/yehoodig]

The rotational axis of the Earth is tilted, relative to its orbital plane, the same plane parallel to which the cosmic rays that create the belts come. In other words, the densest parts of the Van Allen belts are tilted away from the Equator around the Summer and Winter Solstices. If they left Earth during the Summer in the Northern Hemisphere, and went through the belts on the night side of Earth, their necessary trajectory would have been enough, I'm willing to bet.
After some Googling: What do you know, Apollo 11 left Earth in the dead middle of Summer (July 16, 1969) and the Moon was a waxing crescent at launch and approaching First Quarter at the landing (July 20). http://www.moongiant.com/phase/07/20/1969