CASTOR Jr.MIT

2LT Corey Crowell

2LT Matt McCormack

Lucas de la Garza

Spenser Parra

Mission Overview:

Goal: Test the functionality of the communication protocol to be used on MIT’s CASTOR satellite

• Data transmission

- Telemetry data from sensors

- Image data

- Command log of operations that have been performed

• Verify proper system functionality

- Transmit commands to actuators

- Automatically generate commands to actuators

- Log all commands

SHOT II / UN-6 Connection:

Preliminary version of avionics and communications subsystems

• Utilize components that will be incorporated into CASTOR satellite

- Avionics: PIC processors, SD card, camera

- Communications: Transceiver

- ACS: IMU, Magnetometer, Torque Coil design

- Thermal: Sensor suite

- Power: Current and Voltage Sensors

• Preliminary test of operating code and ground station processing - Interface coding to be utilized on the CASTOR satellite

- Ground Station post-processing of data to be performed on all of CASTOR’s telemetry data

SHOT II Design and Test Details:

Design:

• Structure: small and simple, similar to SHOT I design

• Avionics Code: Interrupt-based command processing

• Test-devices:

- Magnetometer and Torque Coil: to measure Earth’s magnetic field and the local magnetic field generated from the coil

- IMU: to measure the angular rate about the flight cord and accelerations before and after balloon rupture/ground impact

- Camera: to record sample images of the balloonsat’s flight

- Temperature Sensors: to measure critical component temperatures, measure external temperature, and regulate activation of the heater

SHOT II Design and Test Details:

IMU

Batteries

Processor

SD Card

Heater

Magnetometer

Torque Coil

Antenna Mount

Camera

SHOT II Design and Test Details:

Testing:

• Operations

- Complete dry-runs of the test procedures to ensure all members are familiar with the CONOPS before flight

- Ensure all systems operate as expected

• Environmental Testing

- Structural whip test

- Thermal environment test

-20 degrees F in freezer

SHOT II Design and Test Details:

Operations:• Pre-launch

- Initialize system, ensure operation of all test systems

• Flight- Continuously collect data

- Query balloonsat from ground station for critical data

- Command actuators from ground station

• Post-flight- Process all data recorded on the

SD Card

- Perform analysis of command log

Expected Results:

Camera:

• 128 x 164 pixel image taken every 15 minutes

IMU:

• Acceleration and rotation data taken every 15 seconds

Magnetometer:

• Magnetic field readings taken every 15 seconds that reflect commands given to the torque coil

Thermal Sensors:

• Data including component and environment temperatures taken every 15 seconds

• Heater operation based upon temperatures

Demonstration:

1. Initialize balloonsat and ground station

2. Take a 128 x 164 pixel image using onboard camera

3. Wirelessly transmit image to ground station