73
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Accepted
Why don't we shield existing CPUs from radiation instead of designing new ones?
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 ...
- 3,382
68
votes
How did Apollo missions solve the cosmic radiation problem?
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 ...
- 123k
54
votes
How did Apollo missions solve the cosmic radiation problem?
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 ...
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48
votes
How did Apollo missions solve the cosmic radiation problem?
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 ...
- 12.4k
32
votes
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How to check, if there is currently an increased solar activity?
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 ...
- 58.2k
21
votes
How much power would a spacecraft's magnetic shield require?
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 ...
- 21.1k
18
votes
How can cosmic ray muons be used to replace GPS for positioning information in 3D on Earth and underwater?
From what that paper says, it's based on the flight time of highly-relativistic muons between a reference detector at the surface and the final detector under the water. There are three or more ...
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16
votes
How big is the risk/potential damage from radiation on a Mars trip?
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, ...
- 58.2k
14
votes
Why don't we shield existing CPUs from radiation instead of designing new ones?
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 ...
- 120k
13
votes
Accepted
Could cosmic rays be produced by alien propulsion systems?
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 ...
- 14.3k
12
votes
Accepted
How are cubesat electronics protected against the effects of radiation in LEO?
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 ...
- 16.2k
11
votes
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Could a spacesuit similar to the suit of Felix Baumgartner be used on the Moon and Mars?
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 ...
- 47.3k
10
votes
Accepted
Can cosmic background be harvested for energy?
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 ...
- 149k
10
votes
Accepted
How radioactive is surface regolith on the Moon?
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 ...
- 149k
9
votes
Accepted
How to test the impact of radiation on cubesat's electronics?
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 ...
- 771
9
votes
Accepted
How are nuclear thermal reactors designed for cosmic rays in space?
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 ...
- 4,538
9
votes
Accepted
Is radiation dose from cosmic rays higher behind 50 cm of shielding, or lower?
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 ...
- 2,247
8
votes
Can cosmic background be harvested for energy?
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 ...
- 2,147
7
votes
Accepted
How much radiation are astronauts on the ISS exposed to?
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 ...
- 471
6
votes
Is there any safety advantage/disadvantage to a particular attitude of a vessel in space?
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 ...
- 583
5
votes
Accepted
How would Solar Flares affect Solar Sail navigation?
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
"...
- 9,129
5
votes
Can cosmic background be harvested for energy?
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 ...
- 1,365
5
votes
How big is the risk/potential damage from radiation on a Mars trip?
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 ...
- 78.7k
5
votes
How are nuclear thermal reactors designed for cosmic rays in space?
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 ...
- 1,138
5
votes
How much power would a spacecraft's magnetic shield require?
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 ...
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5
votes
Accepted
What are the cutting edge materials & strategies which could be used for radiation shielding on long-duration missions?
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 ...
- 8,548
5
votes
Could a spacesuit similar to the suit of Felix Baumgartner be used on the Moon and Mars?
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 ...
- 48.3k
4
votes
Accepted
Is exposure to cosmic radiation more dangerous on some body parts than on other?
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.
...
- 12.4k
4
votes
Accepted
Did the Surveyor missions measure secondary radiation?
Have there been any measurements on neutron radiation performed by the Surveyor (or later) missions?
The Lunar Reconnaissance Orbiter (LRO) has several instruments designed to determine the radiation ...
- 2,084
4
votes
Accepted
Is interstellar plasma a danger for future probes and astronauts?
I asked a colleague (R. Jokipii, a retired expert in this field) about this, and here's my summary of what he told me.
Since the spacecraft separates the plasma outside from the people inside, any ...
- 471
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