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.


“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.


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.


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.


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