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 ...


67

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 flying those missions accepted that dose of radiation with the health risks that come with it. A manned Mars mission will take, at minimum, months of travel. For ...


67

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 shielding but shielding was considered undesirable. There are two main radiation threats in space: cosmic rays and solar flares. Their "defense" against solar ...


35

...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 it's not possible to deflect debris. Things in orbit are moving around at 10 km/s (20,000 mph!) and when they collide, the impact is so energetic they basically ...


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 ...


17

The basic idea here is to turn to have the shield you have towards the Sun. That does actually work, because the radiation from the Sun is directed, with a few exceptions: First, inside a planetary magnetosphere, charged particles are bent, and form radiation belts, for example the Van Allen belts. There, shielding is a bit more difficult. Secondly, that is ...


16

If we have $O_2$ lighted with UV, we have actually many reactions working together: $O_2 + \gamma \rightarrow 2O$ $O_2 + O \rightarrow O_3$ $O_3 + \gamma \rightarrow O_2 + O$ $O + O_3 \rightarrow 2 O_2$ $O_3 + O_3 \rightarrow 3O_2$ $O + O \rightarrow O_2$ (1) produces nascent oxygen. This is slow, and its speed depends on the UV concentration. (2) builds ...


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 ...


12

A Europa lander would need much more shielding, and/or more radiation tolerant components. Juno's orbit avoids the main radiation belt, but Europa is right in the middle of it.


12

This has happened in space before, as a matter of fact, on Mir. During tests of a new manual control system for cargo ships, the cosmonaut piloting the ship managed to crash it into the Spektr module. The crew determined the location of the leak, and after some tense moments trying to sever the various hoses and cables leading into the module, they managed ...


12

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 other materials were too difficult to work with. There are harder and softer lead alloys, but nothing begins to approach titanium. Later on the same page: ...


10

Every Apollo mission sent to the moon was a roll on the dice praying like hell that a major solar flare wouldn't be sending an ejection Earthside. This is why NASA didn't raise that much of a fuss when the last 3 missions were canceled. As demonstrated in the movie "Space" the Lunar Module would have provided no protection whatsoever. The Command ...


8

This is an incredibly complex problem, so the only way I can think of usefully answering your question is by referring you to NASA's Micrometeoroid and Orbital Debris (MMOD) Shield Ballistic Limit Analysis Program and its documentation (PDF). This software complements the NASA's BUMPER-II risk assessment software package that was used for the Orion project (...


8

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-television documentary, "Conspiracy Theory: Did we land on the moon?", cites a reference revealing this. Unfortunately that website I referenced no longer exists. I ...


8

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 bird most likely was a turkey vulture, average mass about 2 kg. The piece of foam that hit the wing leading edge of the Columbia during the launch of STS-107 ...


7

That depends on where the spacecraft lands. The radiation belts rotate faster than the moon so the trailing side of Europa gets a lot of radiation while the leading side gets relatively little. It also depends if the lander will be a separate spacecraft or a part of the orbiter. If it has to go multiple times through the radiation belt with the orbiter, ...


7

Extrapolation is always dangerous but here's my shot at it. I assumed the bullet was a chunk of lead. I have no way of incorporating the effects of any kind of explosive charge in the bullet. Presumably they would increase the damage. I used a chart from Page 60 of here. The chart is for aluminum...here is where some shaky extrapolation gets in...is the ...


7

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 across the ship? What if they chose to all group up at one location? Second, because tardigrades are not as dense as, say, a sheet of iron, you would need to ...


7

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 neighbouring atoms in the metal's crystal lattice. Even non-magnetised iron at room temperature is ferromagnetic, only, the Weiss domains are randomly oriented and ...


7

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 about 6.6 times higher than titanium for 60 keV x-rays. Crank the x-ray source up to 10 MeV and lead is more like 1.82x more effective than titanium, and ...


6

Part of the plan was to time the missions for a time period when the sun was not expected to be active. Secondary plan was to point the Service Module, getting as much mass between the astronauts and the Sun as possible. But likely would have died. Orion is being designed to have an area where they can hang out, in such a case, where the mass of the ...


6

The so-called tyranny of the rocket equation, which becomes clear by examining Tsiolkovsky rocket equation, defining maximum change in velocity $\Delta v$ as: $$\Delta v = v_\text{e} \ln {\left(\frac{m_0}{m_1}\right)}$$ where $m_0$ is the wet mass, $m_1$ dry mass, and $v_\text{e}$ effective exhaust velocity of reaction mass, shows that: Rockets are ...


6

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 operating ranges. Even for terrestrial applications, like electric cars, this is a significant pack engineering constraint, second being safety. Less ...


6

The space shuttle did launch through some birds at least one time with no Ill effects.


6

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 the electron density of the materials. Neutron radiation is more complicated. Metals with high atomic numbers have high electron densities and typically maintain ...


6

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 changing to a lower and lower altitude relative to earth. This suggest to me that the first contact with debris that a satellite (for example, the ISS) would be ...


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

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 are conclusive as to NASA's involvement. RAL has a good bit of material published on the proof of concept magnetosphere and as far as I can tell is the only ...


4

Arthur C. Clarke's Songs of Distant Earth featured a generation star ship which traveled from star system to star system. They would rebuild their water ice forward shield each time they stopped at a star system. The forward shield was needed because impact from even a small speck of dust at small fractions of c could do a lot of damage. Hydrogen and oxygen ...


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