73

Because shielding against radiation is heavy, and weight is the enemy of getting things into space. CPUs are quite sensitive to radiation, and some types of radiation (cosmic rays) are not only quite good at penetrating most things, as they do, they cause a cascade of secondary radiation. To protect a device form any of this radiation getting through is not ...


68

While cosmic radiation is a problem, it's the same as with radiation on Earth: the risk is cumulative. The levels were low enough that missions of 1-2 weeks at this level did not pose a big health risk, so no shielding was necessary. The big remaining problem was radiation from solar flares and CMEs. These produce so much radiation it wasn't possible to ...


54

They didn't, which is why the Apollo astronauts saw blinding flashes inside their eyes during the mission and then had a much higher probability of suffering from cataracts later in life. The flashes were from Cerenkov radiation passing though their eyeballs, occurring as often as 2 per minute on the Apollo missions. Of the 39 astronauts to suffer from ...


48

Apollo solved the cosmic radiation problem in a counter-intuitive manner: by minimizing shielding. Most cosmic rays are very-high-energy atomic nuclei; the rest are very-high-energy protons. When these particles strike something (eg. a sheet of aluminum), they generate a shower of secondary radiation. Any effective shield needs to be thick enough to both ...


32

Looks pretty darned quiet to me right now: You can find that here, along with other measures of space weather. By the way, cosmic rays and solar activity are two entirely different things. Cosmic rays originate from outside of our solar system. The flux of cosmic rays is relatively constant. As for your question about stress, indeed, I just experienced ...


27

Yes, the research on shielding from energetic particles of solar wind plasma using dipole magnetic field continues, and perhaps the best indication of that is the filing of the Spacecraft shield patent (1) in 2010, roughly 2 years after the publication of the Plasma Physics and Controlled Fusion journal (2) that was noticed by the author of that Physics ...


21

It's Monday, so let me rain on this parade a little. Current magnetic shield designs are adequate to protect against ionizing radiation from the sun. They aren't sufficient to protect against galactic cosmic radiation, which has a lot more energy in each particle. To effectively block that would take a shield with energy 100x greater. If Bamford's shield ...


16

If you just stay here on Earth, you have an 18% chance of dying of cancer. Let's first consider a one-way trip, ignoring solar flares and radiation after you land. So just consider the cosmic rays, whose flux is pretty constant and which cannot be reasonably shielded against. If you go to Mars in six months, you'll get 0.3 sieverts, increasing your chance of ...


14

You actually ask a really good question. And the answer is, we do both, depending on the needs. NASA tends to go for the ultra-reliable, and radiation tolerant components are more reliable, thus it is their preferred way. Many commercial satellites, however, use non-space grade components that are shielded lightly, and with software and hardware built in a ...


13

I can't give a precise answer to your primary question besides "Extremely unlikely", but here are some facts on cosmic rays that might help coming to a conclusive answer: Current models are able to describe the distribution of energies and ion masses rather well. What we do not know precisely is the source of this radiation. There are plenty possible ...


11

Radiation shielding in a cubesat (and spacecraft in general) is a tricky thing because radiation shielding adds mostly negative factors to the satellite. In general, the heavier your shielding is and the larger it is, the better it will work. Both of these are obviously no-go for a satellite that's supposed to be as light and as small as possible. This ...


11

Baumgartner's suit is now on display at the Smithsonian Air and Space Museum. The museum's magazine describes that suit as a "pressurized flight suit", not a spacesuit. They are not the same. The suit was not comfortable. A picture in the same article shows a press conference, with the caption "Felix Baumgartner describes the scariest ...


10

I'm guessing you mean cosmic microwave background radiation. A radio tuned to an empty frequency hears "static" noise. A small fraction of the static received by an analog television is in fact the CMB. Could an antenna system collect some of this, and with a diode or something similar, convert some of it to a small amount of useful electricity? CMB ...


10

tl;dr: This is not meant to be a at all a complete answer, but it's a start, and I think it gives a flavor of what will come; that in general the stuff is not very radioactive as (at)Gregg has already predicted. But if your material is in contact with breathable gasses or perhaps even drinkable liquids, don't forget to buy your lunar Radon protection kit ...


9

TL;DR: The medical accelerators are not suitable. There are basically two effects of radiation on electronics: Single event upsets (SEUs) RAM Memory cells are usually small capacitors (caps) which are charged or not to represent a 1 or 0. If an ionizing particle crosses the dielectric between the cap plates, it forms a channel of ionized, and so ...


9

Reactors are, in general, tuned so that the proportion of delayed neutrons (on the order of seconds to minutes after each fissioning) out of all neutrons is enough to make the reactor more or less dynamically stable. (Specifically, the prompt neutrons released within nanoseconds, which are upwards of 95% of all neutrons, aren't enough to match the neutrons ...


8

Those two graphs are not showing the same thing. The lecture slide is misleadingly labeled, but the original paper makes clear that the table is only showing neutrons, mostly produced by shield spallation. That does go up with added shielding (no shielding means no spallation) but the overall dose including other sources goes down. See figure 7 in the ...


7

YES there are raw materials for making plastics other than found on earth(as far as we explored the solar system). Since major of raw material of the plastics are from the petrochemicals (they are chain of carbons and other organic compounds). It is possible to grow genetically engineered plants in space to extract raw material for making plastics We've ...


7

I do know that the Deinococcus, an earth bacteria, has the ability survive in high energy levels of radiation. Chances are NASA is just trying to limit the possibility of an organism going into space alive. Anything is possible. It also would just seem careless to send earth life into space. This is especially true knowing that thermal adaptation in ...


7

It's important to understand the different types of radiation exposure that astronauts can be exposed to. Galactic Cosmic Rays (GCR's) are a more-or-less isentropic throughout the galaxy and are thought to be caused primarily by supernova and black holes in distant systems. However, these are rarely a concern for astronauts in the ISS as GCR's typically don'...


6

Radiation As you have rightly noted, a long cylinder pointing end on to the radiation source (probably the sun, especially during periods of high activity), can be shielded by a smaller, and thus lighter, shield. On the other hand if you need shielding facing all directions, then a sphere is a better choice. (Micro-)meteorites The spaceship is moving ...


6

Yes! If we assume that you have access to a large black hole and materials that probably can't exist, you can run a heat engine off of the cosmic microwave background radiation. Reasonably sized black holes are cold. Very cold. Billionths of a Kelvin for a stellar mass black hole, which is numerous orders of magnitude colder than the CMB. The temperature ...


5

There was a sensor called RAD (Radiation Assessment Detector) on the Curiosity rover, for measuring the inflight radiation does. On the one hand, the results showed that there was a significant radiation dose in flight. On the other hand as Robert Zubrin notes, there was a similar sensor on an earlier flight that showed the same basic levels, and then it ...


5

This response addresses the last part of the question: "what is the proportion between "propulsive power" between the two accelerating factors of solar sail?" Solar Wind is between 1-6x10-9 N/m2 "The wind exerts a pressure at 1 AU typically in the range of 1–6 nPa (1–6×10−9 N/m2), although it can readily vary outside that range." Solar Radiation ...


5

A couple of things: The reference OP provided for cosmic rays states: Cosmic Ray Composition: Cosmic rays include essentially all of the elements in the periodic table; about 89% of the nuclei are hydrogen (protons), 10% helium, and about 1% heavier elements. This implies that neutrons are not a significant constituent of cosmic rays. Since fission is ...


5

This might be of interest: CERN, in collaboration with the European Space Radiation Super Conducting Shield project are using advances in super conductor technology to develop a super conducting magnetic field to protect spacecraft and their occupants. The aim is to create a magnetic field 3,000 times stronger than the Earth's to protect astronauts in a ...


5

You probably want to harvest usable energy, a physicist would rather call that low entropy. Harvesting energy would mean you heat up indefinitely. Accepting that thermodynamics drives deterministic technical processes (as well as life on earth) is is the key to understanding this problem. Most of your field of view, the cosmic microwave background, is ...


5

Most shielding is just mass plus atomic number - for cosmic Ray shielding you want light elements, as heavy elements make more radiation. Water and polyethylene are good options. The main interesting thing is how to make the shielding do double duty. Options include: supplies thermal protection systems fuel/propellant water supplies boxes of food sewage ...


5

A space suit worn on the Moon needs a system for removal of heat produced by the body of the wearer. A system that works in a vacuum without air around it. The suits also had a micro meteroite protection of multiple thin layers. The suit of Felix Baumgartner was used in very thin and cold air, but not in vacuum. It was designed to protect against ...


4

Is radiation more dangerous to some parts of the body than to others? Yes. Health physics uses tissue weighting factors as a way of factoring in the relative sensitivity of different tissue types. Is partial shielding practical? For the most part, no. Some of the highly sensitive tissues are the bone marrow, lungs, and intestines, meaning an effective ...


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