Embedded Files
Introduction
Introduction
This page will act as the Interface Control Document for the ADCS subsystem. It details the electrical, data, mechanical, and thermal interfaces between ADCS and the rest of the spacecraft.
System Interfaces
System Interfaces
Electrical Interfaces
Electrical Interfaces
The electrical interfaces for the subsystem components can be found in the figure below. The majority of components connect to voltage regulators located on the AODC board, which receives power at the common bus voltage. Two exceptions are the thruster, which receives power at the common bus voltage, and the star tracker, which connects to a voltage booster on the communications board.
Data Interfaces
Data Interfaces
The components that are contained in the subsystem, and the data interface they use to connect to the spacecraft is shown in the figure below.
The CDH subsystem will communicate to the AODCS control board via Serial Peripheral Interface (SPI) denoted as SPI 1. The reaction wheel cluster will also connect to the SPI 1 bus. The sun sensors will interface to the AODC board on their own SPI bus, denoted SPI 2. The magnetorquers will interface to the AODC board using PWM. The 3-axis gyroscope and magnetometer on the IMU will interface using I2C. The thruster will interface to the AODC board using an RS232 serial connection. Finally, the GNSS receiver and star tracker will connect to the CAN bus to be used by CDH.
AODCS Data Interfaces
Mechanical Interfaces
Mechanical Interfaces
Thermal Interfaces
Thermal Interfaces
AODC Board (UMS-0054) ICD
AODC Board (UMS-0054) ICD
The schematics for the AODC Board are shown in the figures below. Interface information can be found below that.
Electrical Interfaces
Electrical Interfaces
The AODC board receives power at the common bus voltage, which typically ranges from approximately 6.5 to 7.2 Volts.
Most AODCS components connect to the AODC board for power. They are listed as follows:
The IMU, GNSS receiver, and sun sensors all use a 3.3 V connection.
The magnetorquers and reaction wheel cluster use a 5 V connection.
Data Interfaces
Data Interfaces
The AODCS board connects to the CDH subsystem via SPI. This will be used to send telemetery and sensor readings to CDH, and receive commands.
The majority of the AODCS components have data interfaces with the AODC board. They are listed as follows:
The IMU connects via I2C.
The sun sensors connect to an SPI bus separate from the one between AODCS and CDH.
The magnetorquers will receive PWM signals from the board to generate dipoles.
The thruster connects via RS232.
Mechanical Interfaces
Mechanical Interfaces
Embedded below is the base dimension suite for the Iris ADCS control board (LOTAD). While the LI Bus AODCS board will not have the same circuitry shown, the dimensions remain the same.
Thermal Interfaces
Thermal Interfaces
GNSS Antenna - Antcom 1.2G-Mini-GNSS-AS4 (UMS-0651) ICD
GNSS Antenna - Antcom 1.2G-Mini-GNSS-AS4 (UMS-0651) ICD
Electrical Interface
Electrical Interface
The GNSS antenna connects to the GNSS receiver using a +5.0 Volt DC connection.
PS 1.2G-Mini Electrical Specifications
PS 1.2G-Mini LNA Performance
Data Interface
Data Interface
The antenna will connect to the receiver using an SMA connector.
Mechanical Interface
Mechanical Interface
The engineering drawing for the 1.2G-Mini-GNSS-AS4 is found below.
Thermal Interface
Thermal Interface
PS 1.2G-Mini Environmental Specifications
GNSS Receiver - Novatel OEM719 (UMS-0631/0632) ICD
GNSS Receiver - Novatel OEM719 (UMS-0631/0632) ICD
Electrical Interface
Electrical Interface
Electrical interfaces come from the OEM719 Electrical and Environmental Specifications. The model on LI Bus uses GPS and GLONASS, so will have a typical power consumption of 1.3 W.
OEM719 Power Requirements
The antenna will connect to the receiver via MCX connection.
OEM719 RF Input/LNA Power Output
Data Interface
Data Interface
The GNSS receiver is one of the few components that does not have a data interface with the AODC board. Instead, it connects to the CAN bus to provide CDH and the payload with data directly. The table below comes from the OEM719 Data Communication Specifications.
OEM719 Main Connector Pin Numbering
OEM719 Main Connector Pin Description
Mechanical Interface
Mechanical Interface
The drawing for the OEM719 can be found below or in the product's Mechanical Specifications. The receiver will mount to the structure using four M3 screws.
OEM719 Drawing
OEM719 keep-out zones
Thermal Interface
Thermal Interface
OEM719 Environmental Specifications
Gyroscope - STMicroelectronics A3G4250D
Gyroscope - STMicroelectronics A3G4250D
Electrical Interface
Electrical Interface
Gyroscope Electrical Specifications & Operating Conditions
Gyroscope Absolute Maximum Ratings
Data Interface
Data Interface
Gyroscope I2C connections
Gyroscope Pin Addresses
Mechanical Interface
Mechanical Interface
Gyroscope mechanical drawing and dimensions.
Thermal Interface
Thermal Interface
From the tables given in the electrical interface, the gyroscope's operating temperature range is -40 to +85 degrees Celsius, and the survival temperature is given as -40 to +125 degrees Celsius.
Magnetometer - Memsic MMC5983MA ICD
Magnetometer - Memsic MMC5983MA ICD
Electrical Interface
Electrical Interface
Magnetometer Electrical Specifications
Data Interface
Data Interface
Magnetometer I2C Interface
Magnetometer Register Information
Mechanical Interface
Mechanical Interface
Magnetometer mechanical specifications
Magnetometer Pin Description
Thermal Interface
Thermal Interface
Magnetometer Thermal Specifications
Magnetorquer - UMS-0053 ICD
Magnetorquer - UMS-0053 ICD
Electrical Interface
Electrical Interface
The magnetorquers will connect to the AODC board using a 5 V connection. This results in a maximum power consumption of 0.2 Watts per magnetorquer.
Data Interface
Data Interface
The magnetorquers will be controlled using pulse-width modulation (PWM) signals.
Mechanical Interface
Mechanical Interface
The torque rods will mount to the AODC board and structure using the connectors shown below. The rods themselves mount to the connectors using M2 set screws and the connectors mount using M2 screws.
Thermal Interface
Thermal Interface
The table below outlines the thermal performance of both the magnetorquers and the h-bridges.
Magnetorquer Thermal Properties
Reaction Wheel Cluster - NanoAvionics 4RW0 (UMS-0630) ICD
Reaction Wheel Cluster - NanoAvionics 4RW0 (UMS-0630) ICD
Electrical Interface
Electrical Interface
4RW0 Power Input
4RW0 Power Consumption
Data Interface
Data Interface
4RW0 Enable Signal
4RW0 UART/SPI Signals
4RW0 Pinout Specifications
Mechanical Interface
Mechanical Interface
4RW0 drawing
Thermal Interface
Thermal Interface
4RW0 Temperature Specifications
Star Tracker - Rocket Lab ST-16RT2 (UMS-0626) ICD
Star Tracker - Rocket Lab ST-16RT2 (UMS-0626) ICD
The Interface Control Document for the star tracker can be found on Rocket Lab's website, and is embedded below.
RL - Star Tracker - ICD.pdfElectrical Interface
Electrical Interface
The star tracker
Data Interface
Data Interface
The star tracker will interface with CDH over RS485.
Mechanical Interface
Mechanical Interface
The ST-16RT2 is intended to mount using three M3 hardware. M2 pins can additionally be used for alignment.
Thermal Interface
Thermal Interface
Sun Sensor - York Univeristy MOLTRES (UMS-0381) ICD
Sun Sensor - York Univeristy MOLTRES (UMS-0381) ICD
Electrical Interface
Electrical Interface
The sun sensors will use a 3.3V power connection supplied from the AODCS board. Electrical documentation for MOLTRES can be found below.
ManitobaSat_Project.pdfData Interface
Data Interface
The sun sensors will send data to the AODCS board via SPI.
Mechanical Interface
Mechanical Interface
The sun sensor PCB connects to the mask using M1 bolts. The mask connects to the spacecraft structure using M2 bolts.
Sun_sensor_mask_v5_Rectangluar_Edition_Drawing-Jan2020.PDFSun sensor mask engineering drawing
Thermal Interface
Thermal Interface
Sun Sensor Temperature Specifications
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