ANSWERS TO QUESTIONS Q1. THROUGH Q13.

A1. Passive and active.
A2. Earth terminals.
A3. Approximately one-half.
A4. The extreme polar regions.
A5. The lack of suitable power sources.
A6. To allow maximum solar cell exposure to the sun and satellite antenna exposure to earth terminals.
A7. Large, high-gain parabolic antennas.
A8. To overcome satellite transmitter low power and permit extraction of the desired information from the received signal.
A9. Up to 20 kilowatts.
A10. To receive fleet multichannel tty broadcasts.
A11. Fm or psk.
A12. To ensure earth terminal antennas are always pointed towards the satellite.
A13. Satellite down-link transmitter power and up-link receiver sensitivity.