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In this live stream, we have an astronaut facing the sun (we've seen his hands actually):

enter image description here

I thought people doing an EVA should avoid the sun at all cost, but here he's facing it.

From what kind of deadly things/events does his suit protects him against?

(a rough guess is radiations but a detailed explanation would be appreciated)

Eric Cartman
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  • How about editing your question - including the title - to clarify what you really want. If your question is "What protection does the suit provide" your title is totally inappropriate. – Organic Marble Jun 17 '17 at 01:51

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There is no real reason why astronauts should avoid the sun while spacewalking. While it is true that things like seeing what you are doing, dealing with radiation and heat management are somewhat more difficult the suits are designed for this. Remember that ISS revolves around the earth once every 90 minutes (give or take) and spacewalks can take up to 8 hours. It would be exceedingly difficult to perform a spacewalk where they would have to 'run for cover' every 45 minutes.

The answer on How are EVA's in LEO affected by being at the night side of Earth? has some very good details on how day versus night affects spacewalks.

JDT
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The shuttle/ISS Extravehicular Mobility Unit (EMU) aka spacesuit incorporates a gold-film plated sun visor to protect the astronaut's vision when looking in the general direction of the sun. It is called the Extravehicular Visor Assembly.

enter image description here

from here

In this picture you can see the visor totally raised (gold rim at top of bubble) enter image description here and in this picture you can see the visor half raised. enter image description here

Organic Marble
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  • Why don't they use so called "virtual reality" whre their eyes are safely projected with visualised data from external sensors? (Barring some spelling errors in the code, of course :-) – LocalFluff Jun 17 '17 at 06:32
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    Because VR is far more failure-prone than your eyes. – Hobbes Jun 17 '17 at 07:07
  • Also because VR capable of matching the resolution and sensitivity of the human eye isn't really available – ikrase Aug 24 '20 at 20:03
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  1. Facing the Sun does not mean looking at it. As there are no air there, you have more light looking directly at the Sun, but LESS light looking somewhat in its direction, but not straightly. Because of that, BTW, you can see stars simultaneously.

  2. Even while looking at the Sun directly, you still could do it for the short time enough for taking a photo, without any real harm.

Edit.
The spacesuit protects the wearer from cold, heat, extra visible light, UV, soft roentgen, alpha and beta-rays and protons. A bit from gamma-rays. Earth magnetic field is blocking most of Sun alpha, beta rays and protons and also charged energetic cosmic rays. But not from neutrons and gamma-rays. And the spacesuit and even the spacecraft do not protect from them also. So, the space travels remain very dangerous. Space radiation is 50-fold more effective than typical radiation on Earth at causing a type of liver cancer called hepatocellular carcinoma in mice.

Wiki has much info on the space suits history.

The best fiction literature where space suits are impotant is Have Space Suit—Will Travel of Heinlein.

Gangnus
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  • "Because of that, BTW, you can see stars simultaneously." Do you have a citation for that claim? (Assuming, of course, that you mean stars besides the Sun, but I'm pretty sure that's a reasonable assumption to make here.) – user Jun 16 '17 at 09:30
  • http://curious.astro.cornell.edu/about-us/81-the-universe/stars-and-star-clusters/stargazing/735-why-can-t-you-see-stars-during-the-day-beginner Really, the physics arguments are based not on references, but on thinking based on physical laws. – Gangnus Jun 16 '17 at 13:21
  • There is not much protection by the suits against roentgen or xrays, only against very long waves. – Uwe Jun 17 '17 at 20:26
  • @Uwe Roentgen=xrays. Photons, created by electrons. They start at 2nm wavelength. These soft kind can be significantly weaken by any metal film. On the other hand, waves can be practically very short and still be xrays. https://en.wikipedia.org/wiki/X-ray. These of course, remain dangerous. – Gangnus Jun 17 '17 at 21:18
  • @Gangnus I did know before Roentgen=xrays – Uwe Jun 17 '17 at 21:37
  • @Uwe sorry, it could be understood that you didn't. Anyway, the question is what is protection. I would propose to say "protected" when the person has cancer probability lowered to the normal state. – Gangnus Jun 17 '17 at 21:57
  • I don't believe the stars could be seen simultaneously. The difference in brightness is too big. The human eve may adapt to full sunlight and starlight too, but the adaptation takes time. You could not have a fully opened and closed pupil at the same time. Adaptation of the retina from sunlight to starlight is a matter of about 15 minutes. – Uwe Jun 20 '17 at 20:39
  • @Uwe You can see them simultaneously means you simultaneously have two possibilities: see the Sun or see stars. You have to move your eyes at least from one to the others. It does not suppose that you look at the sun and see stars around it. ... It is in contrast to the Earth, where you can see no stars during the day. – Gangnus Jun 21 '17 at 00:27