PROCESSOR
Processor is based on a 32-digit signal processor TS-21020 with the floating point and a toggle frequency of 16 MHz.
Memory including star catalog.
For Program 640 Kbytes
For Data 512 Kbytes
The processors unit controlling tracker operation is implemented on a gate matrix with 5,000 gates.
There is a 12 digit video signal ADC at the processor input.
Data Exchange is supported via the back up interface MIL STD 1553-B.
The Processors capacity makes it possible to use it for other task solution in the background mode.
ONBOARD STAR CATALOG
CATALOG CONTENTS
Star’s equatorial coordinates
Total number of stars 8,500
Maximum star magnitude +8.5
Number of catalog sectors 642
Maximum number of stars in sector 25
Time of browsing all sectors 30 seconds
(Without prior data about orientation)
DESTINATION, DESIGN AND OPERATION PRINCIPLE
VF STC 1 has been designed for the s/c attitude determination in the onboard star catalog coordinate system. It includes a digital TV camera with a processor.
The VF STC 1 lens projects the starry sky image onto the CCD array.
This image analysis includes:
Localization of the registered images of light sources in the processors image buffer (image buffer capacity is 2048 pixels) and calculation of their energy centers position on CCD array.
Identification of the registered stars with the cataloged objects by angular distances between them.
Determination of the s/c attitude in the catalog star’s coordinate system.
RELIABILITY
Lifetime 15 years
Number of ON/OFF cycles >10,000
Number of the protection cover >10,000
openings/closings.
Probability of failure-free operation
during a 100 hour session
At the beginning of life >0.99995
At the end of life >0.975
Maximum storage time At least 20 years
Radiation stability of the components and materials used makes it possible to apply the modified star coordinate determination unit into geostationary and high apogee orbits.
ILLUMINATION CONDITIONS
Maximum star magnitude +8.5
Registered with an exposure of 0.5 sec.
Coefficient of the lateral >8x109
Solar illumination attenuation
By a system “lens + baffle”
Minimum admissible angle between
The tracker optical axis and direction towards:
The Sun 300
The Earth 300
The Moon 200
S/c structures 300
Illuminated by the sun
TECHNICAL DATA
Dimensions 320 x320 x160 mm
Mass 3.2 kg
Input Voltage 24 – 28 V
Voltage Conversion 27/ +5 V
27 / +15 V
27/ +5 V
27/ +24 V
Power Consumption <10.2 W
Adapter Temperature C -200 +450
TV CAMERA CHARACTERISTICS
Lens
Focal Length 60 mm
Aperture 16 mm
Field of View 80 circular
Spectral Band 0.45 – 1.0 um
Light scattering factor <0.5%
CCD Array
Number of Pixels 512 x 512
Pixel size 16 x 16 um
Minimum data updating frequency 2 seconds