Sat Tech: Introduction

Question 1

Satellite Subsystems (9):

Answer 1

1) Payload
2) Structure
3) Thermal System
4) Mechanics
5) Propulsion
6) Electrical Power System
7) Telemetry, Tracking & Communication (TTC)
8) On-Board Computer Data (OCD)
9) Attitude Determination Control System (ADCS)

Question 2

Major Design Drivers (3):

Answer 2

1) Payload
2) Space Environment
3) Operational Conditions

Question 3

Environmental Conditions in Space close to Earth (6):

Answer 3

1) Vacuum
2) Microgravity
3) Thermal Conditions
4) Radiation
5) Aggressive Residual Atmosphere
6) Micrometeorites and Orbital Debris (MMOD)

Question 4

Vacuum Issues (3):

Answer 4

1) Outgassing, Leaking
2) Heat Transfer (No convection = overheating)
3) Avoid Closed Gas Volumes

Question 5

Gravity Issues (4):

Answer 5

1) Difficult management of liquids
2) Heat Transfer
3) Diffusion of solids (Stalagmite)
4) Every action has a reaction

Question 6

Thermal Condition Characteristics (3):

Answer 6

1) Very cold, very hot - many times
2) ~1370 W/m2 solar power density near Earth
3) Thermal & Mechanical cyclic loads

Question 7

Radiation Characteristics (3):

Answer 7

1) High energy (>MeV) objects deposit energy in materials
2) Increasing of radiation hardness in electronics to avoid failure (mass increase)
3) Redundancy of electronic components to compensate for reduced lifetime

Question 8

MMOD Issues (4):

Answer 8

1) Natural and man-made
2) Can penetrate S/C systems, or cause degradation of external surfaces
3) General Protection and System Redundancy is needed
4) ~ 40,000 little shits orbiting the earth

Question 9

Aggressive Residual Atmosphere issues (2):

Answer 9

1) Surface Material degradation
2) Very important to choose the best material