Subsystems Involved in Making a Satellite

1. Power Subsystem: Provides and manages the electrical power needed by the satellite. It usually includes solar panels, batteries, and power regulation and distribution units.
2. Communication Subsystem: Manages the transmission and reception of data between the satellite and ground stations. It includes antennas, transponders, and frequency converters.
3. Thermal Control Subsystem: Maintains the satellite’s temperature within acceptable limits using radiators, heaters, and thermal insulation.
4. Attitude and Orbit Control Subsystem (AOCS): Controls the satellite’s orientation and position in space. It includes sensors (like star trackers and gyroscopes), actuators (like reaction wheels and thrusters), and control algorithms.
5. Command and Data Handling Subsystem (CDHS): Manages the satellite’s operations by processing commands from the ground and controlling other subsystems. It also stores and transmits data collected by the payload.
6. Structure and Mechanisms Subsystem: Provides the mechanical support and housing for all other subsystems. It includes the satellite’s frame, deployable structures (like antennas and solar panels), and separation mechanisms.
7. Propulsion Subsystem: Used for orbital maneuvers, station keeping, and attitude control. It includes thrusters, fuel tanks, and associated plumbing.
8. Payload Subsystem: The primary mission equipment of the satellite, which could be instruments, cameras, sensors, or transponders depending on the satellite’s purpose (e.g., Earth observation, communication, scientific research).

Difference Between Satellite and Rocket

Satellite:

• A satellite is an object that orbits around a larger object, typically a planet.
• Satellites are used for various purposes such as communication, weather monitoring, Earth observation, navigation, and scientific research.
• They are usually placed in orbit by a launch vehicle (rocket).
• Once in orbit, satellites operate autonomously, performing their designated functions without further propulsion (except for minor adjustments).

Rocket:

• A rocket is a vehicle designed to propel itself by ejecting exhaust gas from a rocket engine.
• Rockets are used to launch satellites, humans, and cargo into space.
• They operate based on Newton’s third law of motion: for every action, there is an equal and opposite reaction.
• Unlike satellites, rockets do not stay in space permanently. Their primary purpose is to provide the necessary velocity and altitude to place a payload (such as a satellite) into orbit.

In summary, a satellite and a rocket are not the same. A rocket is the launch vehicle that delivers the satellite into space, whereas the satellite is the payload that remains in orbit to perform its intended functions.