Could you really have a space colony like the one in Elysium?

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Over at Slashdot, former International Space Station director Mark Uhran talked about whether the amazing space habitat we saw in Elysium is realistic. It turns out the biggest problem isn't what you'd expect.


The space habitat in Elysium is rotating around a central axis, which likely creates enough centrifugal force in the torus to prevent the kind of muscular and skeletal damage that astronauts suffer in zero gravity. So that's slightly realistic. The real problem is the radiation shielding:

On a stationary space station, however, it’s all about the shielding. “After considering active shields which electromagnetically trap, repel or deflect the incident particles, and a passive shield which simply absorbs the particles in a thick layer of matter, the study group chose the passive shield for their design,” read a passage from NASA’s 1975 report, which recommended layering the outside of a habitat with tons of minerals.

How many tons? A table in the report recommends nine megatonnes for a single torus (i.e., a single round with one hole), which brings up a whole new issue: rotating that much mass (in order to establish artificial gravity) would exceed the strength of the materials composing the space station. “Consequently the shield must be separate from the habitat itself and either rotated with an angular velocity much less than 1 rpm or not rotated,” the report adds. “To minimize the mass required, the shield would be built as close to the tube of the torus as possible.”

That shielding could also protect a space station from smaller pieces of floating debris. For best results, Elysium would orbit far above the artificial-debris belt that circles Earth (the result of decades’ worth of satellites, discarded rocket parts, and other random bits). “Two or three times a year, we do get warning—36 to 48 hours in advance—that a piece of debris is in path, and the ISS can maneuver to get out of the way,” Uhran said. “In the future, you’d just be in a very, very high orbit where the debris has a much less density.”

The NASA report actually recommends considering a number of “free orbits” for a space station—including ones nearer the moon, where much of the 10 million tons of matter needed for a large facility would presumably be mined.

The Elysium portrayed in the film seems like a single torus, and lacks the disconnected shield necessary (at least according to current thinking) to block debris and radiation.

So basically everybody on Elysium would be suffering from the effects of radiation poisoning constantly. Maybe that's why they all need medical beds in their living rooms.

Read more at Slashdot


Corpore Metal

Unfortunately, no you can't. At least not as it's depicted in the film.

The retaining walls shown to be supposedly keeping the atmosphere from spilling away into space are about 1600 kilometers too short. We are therefore forced to assume there is some kind of "force field" holding the atmosphere in and keeping the pressure close to Earthly norms.

As shown here as the SSTO VTOL craft coasts in for a landing:

That's shown in the movie as being open to vacuum and, I guess, we're expected to believe that that rotational inertia is keeping all the air below the retaining walls at the edges of the band. But those walls are simply are too short. They'd have to be a good 1000 to a 1, 600 klicks tall for this trick to work.

A better example where the same trick is used is Niven's Ringworld. The walls are of the correct height there.

Now, if the station were fully domed over this wouldn't be a problem.