Mars trips could blind astronauts
A manned trip to Mars could end up blinding its astronauts suggests research by the American Academy of Ophthalmology. The report says that long amounts of time spent in space damages astronauts' eyes. It puts another obstacle in the way of manned Mars missions, which would be a three-year round trip requiring rocket power …
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2001...
Just a quick note to everyone suggesting the idea of spinning / rotating sections, a la 2001.
You are aware that it was a science _fiction_ book....?
Can you be sure that what the author had created would actually hold true in the real world?
Hmmm
If memory serves, Arthur C. Clarke came up with the concept of communications satellites too, so I wouldn't be too quick to dismiss his stories as not-technologically-feasible.
re: 2001...
You are aware that spinning sections are in fact the only reasonably easy to do approach to generating long term artificial gravity in space? There's plenty of fiction in Space Odyssey 2001 but the spinning artificial gravity section is not.
Other examples of the same used in fiction can be found in at least Babylon 5 and PlanetES. Others can probably provide more examples
"Just a quick note to everyone suggesting the idea of spinning / rotating sections, a la 2001.
You are aware that it was a science _fiction_ book....?
Can you be sure that what the author had created would actually hold true in the real world?"
Because Kubrick put a vast amount of time into researching every aspect, including checking out every technical issue with the current world experts. Had you wondered why the 'ape-men' sections were so realistic? Courtesy of the Anthropology section of New York Zoo. The fashions worn at the time? Hardy Amis. He took up a huge amount of NASA technologists time....
"Just a quick note to everyone suggesting the idea of spinning / rotating sections, a la 2001.
You are aware that it was a science _fiction_ book....?"
Which is exactly why so called "tablet computers" are unpossible.
http://www.pcworld.com/article/238664/samsung_claims_tabletlike_device_in_2001_a_space_odyssey_invalidates_apple_patent.html
Specsavers Shuttle Advert
Where the Shuttle lands at Gatwick - not so far fetched after all then!
So...
Whiling away the journey by introducing your old geezer to Mrs Palmer and her five lovely daughters would be double trouble then.
Can't scientists come up with some sort of big hat?
just wondering like.
Out of focus != Blind
Space Adapation Syndrome affecting eyes and meaning that the astronaut needs glasses doesn't necessarily mean that they go totally blind.
Constant acceleration
I thought the mission to Mars would be under constant acceleration / deceleration. Would that provide enough "gravity"? Surely they're not going to coast all the way?
OK, you doubters
Two craft tethered by a 100m cable:
a = v*v/r
For a reasonable amount of artificial gravity (say 0.5g), v would be about 15.7m/s, which would give you a rotation of once about every 20 seconds.
I don't think that would make anyone space sick if you happened to be looking out of a window. And if you needed to kill the rotation to do any fancy manoeuvres, it's only like going from 35mph to 0mph. Easily achievable with modest attitude thrusters.
The motion sickness is more to do with the way that apparent gravity will change as you move around, than with looking out the window. Sitting down, standing up, walking with or against the rotation - they'll all result in a change in acceleration, and the human brain interprets changes in 'g' as falling.
I don't think it would be insurmountable though - some people are less bothered by motion sickness than others, so it might just require careful screening of candidates.
No worse than being on a ship - the ship lurches about with little apparent warning and moves around constantly.
Some people get incredibly seasick, but most are barely affected and even those who are affected almost always get used to it after a few days.
More surprisingly, some people actually get landsick after spending a long time on board ship because the ground *isn't* moving anymore.
You guys should watch 2001. I can't believe nobody suggested this already.
Bah!
Well, lucky for us we're never going to really go then, innit?
Wait: Don't the crew of submarines also go short-sighted after a tour?
Do the Maths
Generating 1g with a rotation needs quite a fast rotation. If you have a 10m radius arm then (assuming my maths is correct) you need a rotation period of around 6s, which puts you at about 20mph. With a 100m radius arm you are doing just under 40mph with a rotation period of around 20s.
Generating those speeds, especially assuming a pretty heavy craft, stabilising the rotation, and stopping it at the far end won't be trivial. It will also require quite a bit of maneuvre fuel over and above the fuel to take you to Mars. Again, not impossible, but also not trivial.
If you can get away with a tiny fraction of g then things become a lot easier. With moon gravity you have 12s per revolution at 10m, and 40s per revoluation at 100m. Half the speed means a quarter of the energy required to get there, and a quarter the fuel load.
On Earth with 1G
your head and feet are so far away from the centre of gravity that there is little differential effect. In a small radius centrifuge there is. That would be far from physiological.
That's why most of the serious design proposals use a tether.
You don't actually need the whole ring, just two modules with a long rope connecting the two.
For bonus points, add a low-mass flexible collapsible tube with a rope ladder between the two so the two halves of the crew can mix without going EVA. Basically like a child play tunnel.
The rope does need to be pretty strong - however it's only taking the weight of *half* the craft (one module plus self weight) so it doesn't need as much strength as you might think, and is well within what we can do now.
Well, spin the damn thing, or develop constant thrust drive. Bonus of CTD is a 28-day round trip.
Problem is more widespread...
I've spent all my life living on a planet with a surface gravity of about 1G. Yet I still have blurred vision and need to wear corrective glasses or contact lenses. I am by no means alone in this.
@ Gardner21
That does bring up the intriguing possibility of what happens when you send someone with blurry vision into space. Maybe their vision would improve!!
Dear Anna...
Please stop writing nonsense like: "...Mars missions, which would be a three-year round trip requiring rocket power beyond what we can currently muster."
NASA could have sent a manned mission to Mars with Apollo era tecnology. In the 1970s several landers reached the surface of the planet, we had the "rocket power" then, we certainly have a lot more now.
long amounts of time spent in space damages astronauts' eyes
Reduced gravity has cited as the most likely cause - known as Space Adaptation Syndrome – includes spatial disorientation, nausea and vomiting.
So does a large amount of time spent on a bar crawl.
I saw this movie once...
It had an old ape in a big white bedroom with a bone in his hand, he was shaking it at this big red eye that called itself Dave. I *think* they had chicks bringing him (the old ape, not the big red eye) food with special slippers that kept their eyes in one place,maybe they can use this for the Mars mission?
Glaucoma
This effect was known long ago with silly sods that climbed mountains. There is too much pressure in the eye balls which in turn damages the optic nerve. I guess the answer is to give all astronauts a trabotomy to reduce this pressure.
Apparently under 20 is OK but for a person going up ito space it needs to be a lot lower.
As one gets older it tends to go up so giving a regular eye pressure test should keep the situation under control and drugs can be used if the situation is temporary.
It is the Monitors.
My eyes have degenerated dramatically since I started spending so much time in front of a computer. I think that this is about the same thing as staring into the sun for prolonged periods, but staring at a monitor works its damage at a much slower rate than the sun will. Monitors just seem to be paper. They aren't.
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