# Apollo 13: perceptual control

**URL:** <http://discourse.iapct.org/t/apollo-13-perceptual-control/1177>\
**Category:** CSG1994\
**Created:** [July 22, 1994, 4:43pm UTC](http://discourse.iapct.org/t/apollo-13-perceptual-control/1177 "1994-07-22T16:43:19Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Tom\_BOURBON3](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/t/85e7bf/32.png) [@Tom\_BOURBON3](http://discourse.iapct.org/u/Tom_BOURBON3)\
**Post date:** [July 22, 1994, 4:43pm UTC](http://discourse.iapct.org/t/apollo-13-perceptual-control/1177/1 "1994-07-22T16:43:19Z")

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> From Tom Bourbon [940722.1025]

Epiphany in Houston. My Brazilian colleague just came in with an excited  
account of his having "got it," with "it" being my insistence that behavior  
is about the control of perception, not control of the "objective"  
environment.

Last evening he watched the PBS series commemorating the 25th anniversary of  
the first manned landing on the moon. The broadcast included accounts of  
all of the other missions before and after that landing. The segment on  
Apollo 13 documented the explosion on board and the ensuing drama while the  
crew and people on the ground devised ways to bring the capsule and crew  
safely to earth. There were many times when things looked pretty bad.

During a critical phase of the re-entry, it was mandatory that the capsule  
be held stable in its trajectory. Too much deviation in any dimension and  
the results would be catastrophic -- bouncing off of the atmosphere with no  
chance of trying again, plunging in as a fire ball, and so on.

While the ground personnel worked to devise ways for the crew to control  
the attitude and trajectory of the spacecraft, time was running out. I wish  
I had seen the re-play of what happened next, but fortunately my colleague  
did -- and he tells me he almost missed it. It was a very brief remark from  
one astronaut to another, something my colleague paraphrased as, "You hold  
the earth still that way (accompanied by a gesture indicating the left-right  
axis) and I'll move it this way." That's all. Then Luis described the  
two astronauts, each gripping a different control stick and wiggling it to  
and fro.

The astronauts had solved the problem of controlling the attitude  
and trajectory of the capsule: they did it (as my colleague said,  
intuitively) by \_not\_ controlling the capsule, but by controlling their  
perceptions of the position of the earth in the window. And it worked.

Later,

Tom