Page 180 - Intro to Space Sciences Spacecraft Applications

Spacecraft Systems
+ USER APPLICATION 167
PAYLOAD
REQUIREMENTS

STORAGE
ORBIT DETERMINATION
M ISSION/PAY LOAD ,, POWER
PECULIAR BUS
AUGMENTATIONS STATIONKEEPING
DOWNLINK

SATELLITE BUS
DESIGN HERITAGE

LAUNCH VEHICLES IMPORTANT COST FACTOR
Figure 8-1. Mission requirements. Many factors affect spacecraft design.

example, precise pointing and stationkeeping, and autonomous operation
for extended periods of time. This theme is further expanded in the fol-
lowing sections that follow the design process illustrated in Figure 8-2
which identifies the salient properties of the mission and payload that
drive the design of satellite bus subsystems:
1. Attitude Reference and Control (ARC)
2. Power
3. Thermal Control
4. Orbital Maintenance (station-keeping)
5. Propulsion
6. Data Handling
7. Onboard Computer
8. Telemetry Tracking and Control (TT&C)
9. Structure.

In the design process, these subsystems are interdependent, and any
design must be iterated so as to take into account interlocking design archi-
tecture, power, envelope, and mass interactions.
The origins of satellite design are mission and payload characteristics.
Mission characteristics establish the environment that the satellite will be
subjected to during its lifetime in space as well as the earth observation
revisit frequency, range from the satellite to earth, velocity, and other
important characteristics, all of which are directly related to the payload