sit down and spread ’em

There are people out there who have no idea how difficult it is to crap in space, and until I read Mary Roach’s book “Packing For Mars” I was one of them.

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“The NASA potty cam is an astronaut training aid. It provides a vivid arresting perspective on something you’ve had intimate contact with all your life but never really seen. Positioning is critical because the opening to a space shuttle toilet is 10 centimetres across as opposed to the 45.5¬†centimetres¬†maw we are accustomed to.

toilet lighters found here

The camera enables you to see if your anus lines up with the centre. Without gravity you can’t reliably gauge position by feel. If your angle of approach is off you can sully the back of the transport tube or plug the air holes.

The re is an alternative positioning tactic called the two-joint method. The distance between the anus and the front of the seat should equal the distance between the tip of the big finger and its knuckle.

knuckle buster ring found here

Here’s something else you may not have considered.

Gravity facilitates what is known in aerospace waste collection circles as “separation.” In weightlessness, faecal matter never becomes heavy enough to break away and drip down on its own. Space toilets utilise air flow “drag” to pull the material away from its source. The seats are designed to also function as a cheek-spreader to facilitate a cleaner break.

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Early Apollo missions used faecal bags rather than sit down toilets. The moulded adhesive ring at the top of the bag rarely fit and the adhesive pulled hairs. Worse, without gravity or anything else to foster separation, the astronaut was obliged to employ his finger. Also under consideration was a defecation glove. The astronaut would reach around and crap in his own palm then peel back the glove and dispose of the contents.

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Given the complexity of this chore, “escapees” or free floating faecal material have been known to plague the crews. There is also the problem of “faecal popcorning”…..

You should probably buy the book if you want to know what that is.

Without gravity to pull things straight, bowel motions tend to curl as they’re coming out. Thanks to some filming done by NASA, their engineers are not only aware of the curl, they know its range of curvature and most likely direction.

The films featured male and female volunteers included gals from the nurses’ corps. The footage was classified as limited distribution but regularly travelled beyond their prescribed limits. They were very very popular.

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Published in: on October 25, 2010 at 7:07 am  Comments (47)  
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unfettered hurls are common

Because not everyone is going to read Mary Roach’s “Packing for Mars” (but everyone should – she is the funniest science writer around), I’ll tell you what she taught me about vomiting in space

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“With motion space sickness, the impulse to vomit can hit with unusual suddenness. Launch-pad workers stuff extra vomit bags in rookies’ pockets before lift-off, but even then, unfettered hurls are common. So what happens if you vomit in your helmet during a space-walk?

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US space helmets have air channels directing flow down over the face at 17 cubic centimetres per minute so the vomit is blown down away from the face and into the body of the suit. There is an extremely remote potential for barf to get into the oxygen return duct. If it somehow did the crew member could shut down the fan and go on ‘purge’ while continuing to get fresh oxygen via his pressurised tank.

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Vomit is a dangerous material to inhale for many reasons not least of which is that stomach acid is capable of digesting the lining of your lungs. so imagine getting it in your eyes. Barf bouncing off the helmet and back into your eyes would be really debilitating. That’s the more realistic danger with in-helmet regurgitation. That and the vision-obstructing visor splatter. Visor glop is a serious astronautical downer.

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Some 50 to 70% of astronauts have suffered symptoms of space motion sickness. “That’s why you don’t see much shuttle news footage the first day or two. They’re all, like, throwing up in a corner somewhere.” says Mike Zolensky, NASA’s curator of cosmic dust. Zolensky himself was epically sick on a parabolic flight. The only passenger worse off was the one helping astronauts practice drawing blood in zero gravity. Since his arms were strapped down someone else had to hold the bag to his face.

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Published in: on October 6, 2010 at 7:25 am  Comments (47)  
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