Image Description -  0692-2

This is an uncaptioned drawing showing the relative orientation of the axes of 
four reaction wheels.  The drawing is divided into four parts.

The first part of the drawing shows four arrows representing the reaction wheel 
axes.  This is a perspective view.  The base of each arrow is at the corner of 
a pyramid.  Each arrow points along the edge of the pyramid towards the apex of 
the pyramid.  Each arrow makes a 25-degree angle with the plane on which the 
pyramid is sitting. 

The second part of the drawing is a perspective view of a coordinate triad.  
One arrow of the triad points vertically upward and is labeled "A2 PITCH."  
On arrow points horizontally to the right and is labeled "A3 YAW."  The third 
arrow of the triad points upward and to the right that indicates that it is 
perpendicular to the plane formed by A2 and A3 and in the background.  The 
third arrow is labeled "A1, ROLL."

The third part of the drawing shows the four arrows representing the axes of 
the reaction wheels again.  In this case the pyramid is being viewed from 
directly overhead.  The pyramid base forms a square in this view.  One side 
of the base of the pyramid is horizontal.  Each arrow points from a corner 
of the square to its center.  The lower left corner of the square is labeled 
"WHEEL 1."  The lower right corner of the square is labeled "WHEEL 4."  The 
upper left corner is labeled "WHEEL 3."  The upper right corner is labeled 
"WHEEL 2."

The final part of the drawing is a coordinate triad.  One arrow of the triad 
points vertically upward and is labeled "A1 ROLL."  A second arrow of the triad 
points horizontally to the right and is labeled "A3 YAW."  The last arrow of 
the triad points out of the plane of the picture and is labeled "A2 PITCH 
(out of paper)."