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How would a spaceship be protected from solar wind and deterioration?
May 9, 2014 8:18 PM   Subscribe

Once we develop the technology of manned, long-term space travel (such as star trek, for example), how would our spaceships hulls and housing be protected from things such as solar wind, other "energy debris", and deterioration?

The Earth is protected by its magnetic field, would our ships need their own magnetic field? Would it need any protection at all?
posted by lain to Science & Nature (8 answers total) 3 users marked this as a favorite
 
Yes. Current deep space designs (e.g. to Mars) are looking at various forms of shielding positioned on the sun-facing side of the spacecraft. Since water and other heavy things are excellent radiation absorbers, one idea has been to store all the water there, as well as the solid waste produced during the mission.
posted by intermod at 8:29 PM on May 9 [1 favorite]


Things like solar wind only matter over very long time frame. Interplanetary space is very, very empty of 'dust' big enough to cause problems. I am not sure what energy debris are.
It turns out that light shielding is worse than no shielding. Radiation will hit the light shield and scatter and actually cause more radiation exposure than the original cosmic ray.
A great intro to a lot of these subjects is a book called the millenial project.. It is a little pie in the sky but the science and engineering is pretty sound at a basic level.
posted by bartonlong at 10:34 PM on May 9 [1 favorite]


On Star Trek, they have "shields," that have been retconned as manipulations of spacetime that are related to the warp drive, which seems to have been retconned as an Alcubierre drive.

In more grounded SF, the answer is usually just fucktons of ice or rubble that ablates away during an interstellar voyage.
posted by ROU_Xenophobe at 10:55 PM on May 9


Although it would not protect from high energy photons such as gamma rays, or particles with neutral charge (like neutrons), charged particles are subjected to a force at a right angle to the direction of their travel while in a magnetic field, such that a strong magnetic field, properly placed, could deflect errant protons into a path "around" your ship.

Let's consider the Shuttle, just to give an idea of what we are working with as sort of a fake spaceship (it is entirely too small for anything but puttering around but let's go with it). The Space Shuttle weighed about ninety-two tons. We would like to enclose the shuttle in a loose box about two hundred feet long, sixty feet wide, and eighty feet of depth. This protective box would be there to stop the gamma rays and anything else not deflected by the "magnetic shielding."

Now, image a sheet of iron. For fifty percent attenuation of 2,100 KeV gamma rays, you need roughly an inch thickness. A foot thickness should get the attenuation down to a mere 0.024% and you would have a weight thick enough such that it would not easily buckle. This should allow our travelers a decent passage without ending up with various damage to their DNA from radiation, and should also serve as a decent shield against any wee rocks floating about. When you're moving quickly, even a small grain of rock could punch through more flimsy structures.

With the above "box," you would need 113,356,800 cubic inches of iron. This works out to be about 16,123 tons, far exceeding the mass of the shuttle, the aforementioned ninety-two tons. In the shuttle's history, since 1981, it has boosted 1,500 tons of cargo into orbit. It would take a great many missions to lift these slabs up into orbit if manufactured on Earth, assuming we don't have some form of "Beanstalk" developed by then.

More practically, it would be smart to send semi-autonomous probes out to metal-rich bodies in the asteroid belt far ahead of time, such that they could be mined for thick slabs of metal to be arranged around the ship, such that you could have a few antennae and sensors sticking out; the entire arrangement might be more tenable than trying to lift into space such slabs manufactured on Earth. You would still need to develop a decent power source (fusion, eternally fifty years away) to power your little mining and smelting robots but we could probably develop the robotics required today, once we spent a lot of money on radiation-hardened processors and the like.

Additionally, I imagine the travelers would be heavily modified themselves, possibly using tricks from species like deinococcus radiodurans — an organism which has tricks to resist and repair damage caused by ionizing radiation — to keep themselves in good repair.
posted by adipocere at 10:56 PM on May 9 [2 favorites]


In Star Trek they have "deflectors" which are some sort of field emitter which deflects particles away from the ship.

The "shields" are different, they are force fields that protect the ship from energy weapons and objects that are too big for the deflectors to handle.

The fictional technology might be similar, but they're different subsystems. The deflectors are "always on" whereas the shields are activated in response to events.
posted by under_petticoat_rule at 10:58 PM on May 9 [2 favorites]


when interstellar ships get up to almost-light speeds, they will be shaped like needles with repellent fields around them to avoid hull-busting particles at relativistic speeds. they will be fueled by little black holes at the rear end which have accretion disks shooting enormous energy out the backside. i haven't figured out how to protect the crew cabin against the energy shooting out the frontside yet.
posted by bruce at 11:13 PM on May 9 [1 favorite]


I've got to be the contrarian here, and say this question is unanswerable before we HAVE that FTL space drive --- we don't know what that FTL drive will require for fuel, if it'll require something like a non-metallic shell (for instance, the ship might have to have some sort of specialty plastic body!), or other problems we can't even envision right now.
posted by easily confused at 2:29 AM on May 10


In Arthur C. Clarke's The Songs of Distant Earth, the spaceship has a massive shield of ice which was manufactured from water on the moon (so it didn't have to be lifted by a rocket). I think other semi-realistic scifi uses that convention.
posted by miyabo at 7:53 AM on May 10


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