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The coarse sun sensor assembly consists of two identical half sphere
sensors, providing complete 4 
steradian sun direction information.
Each sensor provides angle information of the sun line with respect to
two perpendicular axes.
The spacecraft coordinate system is right handed ( 
).
The 
axis points towards the sun within 
20 
.
The symmetry axis of the sensors is mounted in-line with the
- 
axis and + 
axis, respectively.
The sensor outputs correspond to one angle in the 
-plane
and one angle in the 
-plane with nominal zero output
when the sun is in the - 
or - 
direction.
The sensitivity for the inner region ( 
0.1 rad) is of
the order of 100 mV/rad within either of the symmetry planes
( 
-plane or 
-plane of the sensor).
The output is a monotonic characteristic between -83 
and +83 
.
Between 83 
and 97 
the characteristic decays linearly
to zero.
| Range | 4  |
| Zero bias error |  0.50 |
Tolerances on 83  , 97  points |  10 |
| Tolerances on output voltage |  5% when illuminated with
1 solar constant |
The measurement performance parameters are given in Tab. 1.2.
After the Y-gyro loss, the CSS has been used for coarse target acquisition. A software patch in the AMCE was designed and tested, and has been in operation since the start of 1991 October. After the Z-gyro loss in 1993 October, the CSS has been used together with the magnetometer, the S-gyro, and the degraded X-gyro for attitude control.