73
votes
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 ...
- 3,442
66
votes
Why can't we use the same radiation shielding in Mars that we used when going to the moon?
In addition to what Russell Borogove says about cumulative risk you're operating under a false assumption--that there was shielding on the Apollo capsules.
Not only did the Apollo capsules not have ...
- 11.7k
66
votes
Accepted
Why can't we use the same radiation shielding in Mars that we used when going to the moon?
Radiation exposure is a cumulative risk. The more radiation you receive, the more likely you are to develop cancers.
The Apollo missions took no more than two weeks to complete; the astronauts ...
- 172k
36
votes
Accepted
Should man-made satellites feature an intelligent inverted "cow catcher"?
...adjust the angle of the cow catcher to deflect earthward
The catcher could be coupled in a way that would allow it to absorb impact gradually by continuous springs.
The problem with this is that ...
- 510
21
votes
Accepted
Would the reflected sun's radiation melt ice in LEO?
Would the reflected sun's radiation melt ice in LEO?
This is an elegant question and an interesting challenge because though very simple to ask requires a lot of real, practical spaceflight ...
- 151k
17
votes
Accepted
Has depleted uranium been considered for radiation shielding in crewed spacecraft beyond LEO?
Is DU, in fact, the best shielding by mass?
The first thing to note is that the given quote from Wikipedia is not very relevant for the case of shielding of spacecraft: It refers to shielding against ...
- 15.2k
16
votes
Accepted
Could ozone be used in a biodome on Mars?
If we have $O_2$ lighted with UV, we have actually many reactions working together:
$O_2 + \gamma \rightarrow 2O$
$O_2 + O \rightarrow O_3$
$O_3 + \gamma \rightarrow O_2 + O$
$O + O_3 \rightarrow 2 ...
- 3,342
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 ...
- 122k
12
votes
Why make X-ray shielding from titanium, when lead is 6 times lighter?
From the NASA web site for Juno:
While other materials exist that make good radiation blockers, engineers chose titanium because lead is too soft to withstand the vibrations of launch, and some ...
- 12.9k
8
votes
Could an Apollo crew have been killed by Solar radiation?
Yes, they could have been killed if a solar flare had erupted. My 1st-year university essay which I wrote in 2009 as a 64 year old mature student, refuting the dilly claims of the 2001 made-for-...
- 527
8
votes
Can a flock of birds crash a rocket?
As noted in Johnny Robinson's answer, there has been at least one recorded incidence of bird strike during launch. This was STS-114, the first Shuttle launch after the fateful STS-107 mission. That ...
- 77.4k
7
votes
Accepted
Using tardigrades as space shielding
This would not be very feasible. There are several reasons. First, living creatures are unpredictable and uncontrollable. How could you be sure that all your tardigrades would maintain an even layer ...
- 5,636
7
votes
Accepted
Liquid shield for spacecraft?
Could liquid metal be made ferromagnetic by externally inducing an internal magnetic field?
No. Metal is either ferromagnetic or not; this is a result of the quantum-mechanical interaction of ...
- 3,771
7
votes
Accepted
Why make X-ray shielding from titanium, when lead is 6 times lighter?
First things first:
A titanium [dentist's patient] apron would weigh about 6.6 times a lead apron.
This is true in their specific example, because the mass attenuation coefficient of lead is ...
- 8,188
6
votes
Can Li-ion batteries replace parts of the physical structure of a spacecraft, such as the hull of a crewed spaceship?
The biggest argument against this is thermal control. Batteries are one of the most thermally sensitive components of spacecraft, and normally require careful thermal design to make sure they stay in ...
- 1,320
6
votes
Accepted
Can a flock of birds crash a rocket?
The space shuttle did launch through some birds at least one time with no Ill effects.
- 4,924
6
votes
Accepted
What is the shielding capability of liquid metal compaired to solid metal?
The ability of a metal in the liquid state to block radiation is quite similar to the same metal in the solid state.
Ability to block alpha, beta, gamma, and x-ray radiation typically scales with ...
- 2,035
6
votes
Should man-made satellites feature an intelligent inverted "cow catcher"?
binaryfunt explained the problem with speeds and energies, but I'll comment on one your assumptions:
My understanding is that since satellites gradually succumb to gravity their path is constantly ...
- 161
5
votes
Accepted
3D Model of radiation in earth orbit?
The level of detail you seem to want probably requires the use numerical radiation software. I would recommend the free SPENVIS package made available by the European Space Agency or SRIM software. ...
- 1,730
5
votes
Accepted
How thick must a shield be to be better than no shield at all?
First of all let's define what the radiation is:
alpha (helium nucleus i.e. two protons and two neutrons)
beta (electrons)
gamma (high energy photons)
neutrons
ions (bare stripped nucleus)
other ...
- 902
5
votes
Accepted
Is NASA doing research on "mini-magnetospheres" to protect crew from radiation in space?
I've been trying to find a link between the mini-magnetosphere actually created at Rutherford Appleton Labs (U.K.) in 2013 to NASA. So far there's only anecdotal reports and interviews none of which ...
- 66
4
votes
Accepted
Could an Apollo crew have been killed by Solar radiation?
There were plans in place to deal with a large scale CME. These storms would not have been instantly deadly, but could have caused a serious case of acute radiation syndrome. The plan was if such an ...
- 122k
4
votes
Could a Sun shield keep a rover cool daytime on Mercury?
As Hobbes pointed out, the ground under the rover will eventually warm up. Any thermal barrier only slows down the heat transfer. It would eventually cook from below.
The only thing that I can ...
- 910
4
votes
Accepted
Is the amount of damage to humans due to x Sievert a function of exposure time?
As your link already points out, the regulatory assumption is that there's a "linear, no-threshold assumption". This means that doubling the time and halving the radiation intensity cancels out.
We ...
- 1,654
4
votes
Accepted
Can you avoid the costs of cooling superconductors for magnetic shields by separating them from the spacecraft and using shades?
A lot depends on the temperature requirements for your superconductors. That in turn depends on how much magnetic field you need, your mass budget for the coils, and how exotic a material you can ...
- 12.9k
4
votes
Can you avoid the costs of cooling superconductors for magnetic shields by separating them from the spacecraft and using shades?
Deflecting charged particles will also take energy, you constantly have to add new current to the coil.
No, magnets do not change the energy of the particle, just their momentum. Otherwise permanent ...
- 15.2k
4
votes
Accepted
Would a Faraday cage made of gas block radiation?
Gas is mostly not matter, that's why you can move through gas so easily. This is why it blocks virtually no radiation. It's also why it does block electric currents; that needs a conductor. If you do ...
- 1,654
4
votes
Accepted
What is currently used to protect spaceships from meteoroids?
Interstellar travel typically involves much higher velocities than current probes achieve. Depending on how long you are willing to allow the mission to take, you need velocities of a decent fraction ...
- 19.7k
4
votes
When a coronal mass ejection (CME) hits a spacecraft, from which direction will the particles come?
A single CME will impact a spacecraft from only one direction, but that direction might not be directly from the sun because a CME may zigzag en route. So unless you can know in advance from which ...
- 12.3k
Only top scored, non community-wiki answers of a minimum length are eligible