CONTROLLER
The controller’s primary function is to adjust the satellite’s orientation. The controller works with other components to orient the satellite to specific angles and directions, as specified by the mission needs. This may include the rotation of a satellite’s solar panels toward the sun!
GNC
SUBSYSTEM
Guidance, navigation and control, or GNC, is a subsystem that moves a satellite’s orientation or altitude. Components within the GNC convert momentum to adjust the orbit of a satellite. The GNC includes the controller, reaction wheels, star tracker, GPS and torque coils.
REACTION WHEEL
Reaction wheels help rotate and accurately re-orient the satellite in specific increments. Rather than using fuel, a reaction wheel adjusts a satellite's orientation according to speed and torque. Since reaction wheels only rotate on a single axis, multiple reaction wheels may be installed to provide multiple degrees of movement.
GNC
SUBSYSTEM
Guidance, navigation and control, or GNC, is a subsystem that moves a satellite’s orientation or altitude. Components within the GNC convert momentum to adjust the orbit of a satellite. The GNC includes the controller, reaction wheels, star tracker, GPS and torque coils.
STAR TRACKER
A star tracker is an optical device that helps determine a satellite’s orientation in relation to stars. To assist with positioning, a star tracker obtains images of nearby stars and compares them to a star catalog. Common star trackers include a camera, photocells and telescope.
GNC
SUBSYSTEM
Guidance, navigation and control, or GNC, is a subsystem that moves a satellite’s orientation or altitude. Components within the GNC convert momentum to adjust the orbit of a satellite. The GNC includes the controller, reaction wheels, star tracker, GPS and torque coils.
GPS
A Global positioning system, or GPS, is a component that measures position, time and velocity. GPS uses a space-based radio navigation software, also known as GPS, to receive radio frequency transmissions. A system may send transmissions to and from other satellites to locate its own position on a mapped grid.
GNC
SUBSYSTEM
Guidance, navigation and control, or GNC, is a subsystem that moves a satellite’s orientation or altitude. Components within the GNC convert momentum to adjust the orbit of a satellite. The GNC includes the controller, reaction wheels, star tracker, GPS and torque coils.
TORQUE COILS
Torque coils are coiled magnetic wires that generate torque. Torque is generated by interacting with the Earth’s magnetic field, using angular momentum to push a satellite in the opposite direction of the desired momentum. Torque rods are an alternative to torque coils and serve the same function.
GNC
SUBSYSTEM
Guidance, navigation and control, or GNC, is a subsystem that moves a satellite’s orientation or altitude. Components within the GNC convert momentum to adjust the orbit of a satellite. The GNC includes the controller, reaction wheels, star tracker, GPS and torque coils.
TRANSCEIVER
The transceiver is a radio device used to receive and transmit data and radio frequencies between a satellite and ground station. It receives and transmits data from the satellite’s payload, sensor suite, or any specific commands or telemetry in the vehicle. The radio works with the antennas to amplify radio frequencies and electromagnetic waves.
TT&C
SUBSYSTEM
Tracking, telemetry and command, or TT&C, relays communication and transmits data between Earth and a satellite. TT&C monitors the satellites’ condition, communicates its exact location and communicates ground input to the device.
ANTENNAS
A satellite’s antennas are responsible for sending and receiving radio frequency signals. Antennas collect electromagnetic waves to route the signal back to the receiver and strengthen signals in specific directions. These radio frequencies are used for two-way communication between satellites and their ground systems.
TT&C
SUBSYSTEM
Tracking, telemetry and command, or TT&C, relays communication and transmits data between Earth and a satellite. TT&C monitors the satellites’ condition, communicates its exact location and communicates ground input to the device.
SOLAR ARRAYS
Solar arrays are a group of solar cells or panels arranged in specific formations on a satellite. They are the primary method of power generation Solar arrays are responsible for harnessing the sun’s energy and converting it into power for the satellite.
EPS
SUBSYSTEM
The electrical power subsystem, or EPS, stores, moves and distributes power across the satellite during operation. Power is generally stored in a satellite through a variety of primary and secondary methods, including batteries, solar cells, solar panels, solar arrays and power switch boards.
BATTERIES
Batteries act as a main source of power storage and manage electrical loads. Primary batteries are generally not rechargeable, so they work with secondary batteries and solar arrays to recharge power storage, extending mission life. Specific battery types within a satellite are chosen according to power-to-mass optimization.
EPS
SUBSYSTEM
The electrical power subsystem, or EPS, stores, moves and distributes power across the satellite during operation. Power is generally stored in a satellite through a variety of primary and secondary methods, including batteries, solar cells, solar panels, solar arrays and power switch boards.
POWER SWITCH BOARD
The power switch board, or PSB, distributes power across a satellite through a series of switches, working with the rest of the electrical power subsystem for power and load management. Common loads within a satellite include heaters, batteries and radios. The power switch board communicates with the flight computer to moderate switches.
EPS
SUBSYSTEM
The electrical power subsystem, or EPS, stores, moves and distributes power across the satellite during operation. Power is generally stored in a satellite through a variety of primary and secondary methods, including batteries, solar cells, solar panels, solar arrays and power switch boards.
FLIGHT COMPUTER
The flight computer assists with data processing, input and output processes and data management. It is continuously analyzing data, acting as a satellite’s central processing unit. The flight computer works with all other subsystems to carry and store data across the satellite.
CD&H
SUBSYSTEM
The command and data handling subsystem, or C&DH, controls all spacecraft functions and data management. This includes calculating spacecraft position, sending and preparing data and command management. Common components include the flight computer and avionics system. C&DH works alongside the tracking, telemetry and command subsystem to communicate data back to a ground station.
HEATERS
Heaters are composed of etched foil or wire sandwiched between temperature resistant elements. They provide additional heat to components, ensuring individual components operate at their optimal temperature needs.
TCS
SUBSYSTEM
The thermal control subsystem, or TCS, keeps the satellite within normal operating temperatures throughout launch and deployment. Normal operating temperatures typically range between -30C and +61C, but can vary based on the individual component or mechanism. Maintaining each component’s ideal operating temperature is critical for the satellite’s survivability and operation while on orbit. Common TCS components include heaters, temperature sensors, multi-layer insulation and radiator coatings.
TEMPERATURE SENSORS
Temperature sensors sense the internal temperature of a satellite. Thermistors are the primary tool used to accurately measure temperature across various ranges, and do so by measuring resistance.
TCS
SUBSYSTEM
The thermal control subsystem, or TCS, keeps the satellite within normal operating temperatures throughout launch and deployment. Normal operating temperatures typically range between -30C and +61C, but can vary based on the individual component or mechanism. Maintaining each component’s ideal operating temperature is critical for the satellite’s survivability and operation while on orbit. Common TCS components include heaters, temperature sensors, multi-layer insulation and radiator coatings.
SPACECRAFT STRUCTURE
The spacecraft structure is the mechanical design used to support and protect the satellite. The spacecraft structure is dependent on launch requirements and works with all other subsystems to ensure mission success. The structure subsystem is generally made of aluminum, steel, titanium and carbon.
STR
SUBSYSTEM
The structure is the primary and secondary structure components that support and protect the satellite. Structure ensures that each component fits within the available volume mass and that subsystems are placed correctly, according to their needs.
LAUNCH & DEPLOYMENT
The launch adapter enables the mating of the satellite structure to the launch vehicle. Each launch provider has their own adaptor. Deployment mechanisms work in tandem with the launch adapter to deploy a satellite. It is designed to release and push the satellite away from the launch vehicle.
STR
SUBSYSTEM
The structure is the primary and secondary structure components that support and protect the satellite. Structure ensures that each component fits within the available volume mass and that subsystems are placed correctly, according to their needs.
PAYLOAD
A payload can refer to a physical object, software, or area within the satellite. The payload enables the mission. Common payloads include scientific experiments, observation equipment and specialized computers.
STR
SUBSYSTEM
The structure is the primary and secondary structure components that support and protect the satellite. Structure ensures that each component fits within the available volume mass and that subsystems are placed correctly, according to their needs.
SMALL SATELLITES 101
A satellite is defined as a natural or man-made object that orbits around a body. There are natural satellites (such as the moon and Earth) and man-made satellites composed of mechanical components. A small satellite, also known as a SmallSat, is a classification of satellite that is compact and falls under a specific mass line. Individual components of a satellite work together to execute specific functions while in orbit. These functions can include observation of astronomical objects, movement, and communication through space. Small satellites can work independently or in a versatile network to execute specialized missions such as observation, communication, or scientific experiments.
