A Side Effect Of Space Travel No One Thought Of...

[mosaix]

Apparently long space missions may damage eyesight.

http://www.bbc.co.uk/news/science-environment-17354304

[Huttman]

long sigh..........Maybe I should research this a little further before I comment, nah, here is my two pence; I have always loved anything space from real goings on to far-fetched movie stuff. When I was old enough to understand there is no gravity in space they compensated for that with artificial gravity, something I wholeheartedly believe we will have someday. For the here and now, we do not. Select few of mankind has been traveling in weightlessness for about 50 years now and for a good portion of that time they have known of the deteriorating effects on the human body when it does not have gravity for a length of time. So a bunch of people get together and decide to build an international space station that will cost billions of dollars and be good for only, what, 10 years? That's not my point, my point is that it has no gravity on it! But wait you say, we haven't made that artificial gravity discovery yet. Well, in 1968 they made this odd little hippie loved film called 2001: A Space Odyssey, and in this film they had this space station, this big, double wheel looking thing that spun and simulated the effect of gravity through inertia. What a great idea.

Since science knows the pitfalls of weightlessness on the human organism, why o why don't we build an international space station like the one in that movie. There would even still be weightlessness in the center of the wheel to conduct all those science experiments that they tinker with on our current future Skylab (it finally became ocean lab). Seriously, if anyone knows the downfall of that idea for the wheelie space station, let me know, OK?

[Dave]

Keeping the light on in a child's bedroom when they go to sleep damages their eyesight - according to research last year.

Old age damages your eyesight.

I' won't have sleepless nights about the effects of space travel.

[mosaix]

Originally Posted by Huttman

lSeriously, if anyone knows the downfall of that idea for the wheelie space station, let me know, OK?

I always thought that they made docking seem a tad too easy in 2001.

[HareBrain]

Originally Posted by mosaix

I always thought that they made docking seem a tad too easy in 2001.

It was certainly much harder in Elite, until you bought a docking computer.

[iansales]

Originally Posted by Huttman

Well, in 1968 they made this odd little hippie loved film called 2001: A Space Odyssey, and in this film they had this space station, this big, double wheel looking thing that spun and simulated the effect of gravity through inertia. What a great idea.

That's because no one writes science fiction - or makes science fiction films - which actually show what it's really like. It's all magic technology and a blithe disregards for the difficulties and dangers of getting into space and travelling through space. You might as well expect an epic fantasy novel to accurately depict life in the Middle Ages...

[Michael01]

And wouldn't it take a lot of resources to build it? I understand a space station like that would have to be pretty big, wouldn't it?

[Abernovo]

Like Dave, I'm not going to let it worry me too much.

I keep seeing these types of reports, with big headlines about how dangerous X is. I also remember my grandmother's words: 'we're all going to die of something, so we might as well try to enjoy life whilst we've got it'.

We'll just have to start building rotating stations, as Huttman says. Perhaps start with two pods with trusses joined to an axle. Of course, by then the papers will have other pronouncements of doom.

[Vertigo]

A space station like that would have to be very big. In fact the rotating spaceship later in the 2001 filem is one of the technically weak points in the film. It too rotated to give pseudo gravity, however in this case the diameter of the rotating section is too low meaning the speed of rotation would be moderately high. The crew would have terrible trouble with their inner ears due to the coriolis effect. In order to avoid this problem the rotation must be very slow and if you want significant pseudo gravity then the space station wheel would have to be significantly big. Big in space means seriously expensive. The ship in 2010 was, as I recall, much more realistic.

[Michael01]

Originally Posted by Vertigo

A space station like that would have to be very big. In fact the rotating spaceship later in the 2001 filem is one of the technically weak points in the film. It too rotated to give pseudo gravity, however in this case the diameter of the rotating section is too low meaning the speed of rotation would be moderately high. The crew would have terrible trouble with their inner ears due to the coriolis effect. In order to avoid this problem the rotation must be very slow and if you want significant pseudo gravity then the space station wheel would have to be significantly big. Big in space means seriously expensive. The ship in 2010 was, as I recall, much more realistic.

Yeah, that's what I thought. Big and expensive. I think I heard (or read) something like two miles (was that diameter?), but I'm not sure. Been a while. In fact, that sounds a bit small...

I'm not that old, but my memory tends to be elusive sometimes.

[Kaladan]

Dammit, why is it that everything a young man REALLY wants to do damages the eyesight!?

[Metryq]

The pressure on the optic nerve is caused by excess fluid in the upper body. Muscle action has evolved to push body fluids upward against gravity. (This is why giraffes have such high blood pressure.) In freefall, this results in the puffy faces seen in spaceflight video, and it is how Wally Schirra ended up on TV endorsing head-cold medicine. Skylab astronauts experimented with vacuum pants designed to draw body fluids back into balance.

As noted by Vertigo, a small diameter centrifuge would produce more pronounced Coriolis effects than a larger one:

Frame Effects and Space Stations

It is not necessary to spin fast enough for Earth normal gravity, although a diminished acceleration compromises the benefits of the simulated gravity. And there are numerous problems with designing a rotating habitat on a ship. While there are conceptual designs to maintain the direction of "gravity" under variable thrust of the ship, the gyroscopic effects would present steering problems. At the moment, it would seem that the cheapest and simplest solution to the problems of long-duration spaceflight is (drumroll, please) to shorten the transit time with advanced propulsion systems, like nuclear thermal rockets.

[Overread]

Originally Posted by HareBrain

It was certainly much harder in Elite, until you bought a docking computer.

First time trying to land at a rotating space station in X-Beyond the Frontier - I died so many times before I learned to rotate the ship to match --- then before I learned to slow the heck down on the approach

[ktabic]

Originally Posted by Michael01

Yeah, that's what I thought. Big and expensive. I think I heard (or read) something like two miles (was that diameter?), but I'm not sure. Been a while. In fact, that sounds a bit small...

I'm not that old, but my memory tends to be elusive sometimes.

Wouldn't need to be that big. You could get away with something with a radius of about 225m. That would give you 1G at 2rpm.
But you wouldn't necessarily need to get to 1G. Even providing something like 0.75G should still help off-set the downsides of microgravity.

[Vertigo]

Well 2rpm is generally considered to be the fastest you could have a rotation without affecting the inner ear seriously. So if we went for say .5g then you would still need a diameter of around 100m at 2rpm. Bearing in mind the biggest man-made object in space is the ISS at 51m wide, 109m long, 20m high. That would suggest a structure at least twice the size of the space lab. Then stop and consider the effect of rotating it on solar panels, and all other sensors, antennas etc. and the problem becomes not insignificant.

I'm sure that is what we will eventually end up with but I think it might be a while before we get it.