Page 181 - Intro to Space Sciences Spacecraft Applications

168 Introduction to Space Sciences and Spacecrafi Applications
Mission
- Altitude
- Inclination
- Launchyear
- Life span Payload
\ - Mass Satellite Subsystems
- Power
- Attitude reference
- Data rate and control
- Pointing - Power
requirements
- Thermal
\ - Orbit maintenance
- Propulsion
- Data handling
- On-board computer
- TT&C
- Structure
Figure 8-2. Satellite design flow diagram.

application. Payload attributes such as dynamic mass and envelope
dimensions, data collection and transfer rates, power profiles, and point-
ing and stabilization requirements also determine the design requirements
for the satellite bus subsystems.

Mission

Specification of the six orbital elements is determined by user applica-
tions requirements concerning temporal (scene revisit frequency), field of
view, solar illumination geometry, and other important considerations.
Part of the mission design process includes decisions about the launch
vehicle’s role in achieving the final orbit and how much propulsion the
satellite design must provide for the satellite to reach its final destination.
Specifically, the mission affects the entire design because it establishes
the environment and duration for the satellite’s lifetime. The orbit influ-
ences the power subsystem by setting the eclipse times and mission life-
time that the solar panel output must comply with; the orbital maintenance
subsystem by determining the neutral density environment that causes
drag and the time duration that the satellite will be exposed to this orbit-
modifying force; and the satellite propulsion subsystem by determining
the Av necessary to achieve final orbit.