Prox-0.3

Georgia Institute of Technology

Kiichiro DeLucaRichard Zappulla

Matt UhlmanIan Chen

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Mission Overview:

• System Level Integration of Critical Subsystems

• Opportunity to integrate subsystems that are critical to satellite survival: Command and Data Handling, Electrical Power, and Thermal Control.

• Flight Testing of Critical Subsystem Components

• Power Management and Distribution Board

• Power MOSFETs and Thermistors

• Image Acquisition/Storage and On-board Processing

• Visible image acquisition through web camera

• Visible image storage on flash storage

• OpenCV library for on-board image processing 2

SHOT II / UN-7 Connection:

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Prox-0.3 is a scaled down version of the survival critical subsystems on Prox-1

Prox-0.3 contains many of the same hardware to be used on Prox-1

• BeagleBoard and Arduino

• Power Management & Distribution

• Patch Heaters, MOSFETs, and Thermistors

SHOT II Design – BalloonSat System:

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SHOT II Design – Command & Data Handling:Primary Objectives:

1. Demonstrate overall C&DH architecture functionality and viability

2. Demonstrate reliable communication between FCE and SMC

3. Demonstrate basic data-logging functionality

4. Demonstrate basic flight software functionality and reliability at the hardware/software interface

5. Demonstrate basic image acquisition

Secondary Objectives:

1. Demonstrate on-board IPA on pre-loaded images

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SHOT II Design – Command & Data Handling:

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Logic Level Shifter / SMC

Level-Shifter Schematic

FCE / Visual Camera

SHOT II Design – Electrical Power:

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Battery Specifications:•9V Cells•18V Bus voltage•4480 mAh capacity

Design:•4 sets of 2 cells in series connected in parallel•Ground terminals connect to ground plane•Power terminals are spliced together to send to switch

SHOT II Design – Thermal Control:

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• Foam insulation board provides passive thermal protection against the thermal environment at high altitude.

• Heaters provide active means to providing heat to specific components.

• Varying current through the thermistor provides microcontroller the temperature at the thermistor location.

• At the specified “on” temperature (currently set to 15°C), microcontroller sends current to the LED and to the MOSFET, in turn signaling the heater to turn on.

• Current will stop flowing to the MOSFET and the LED when temperature reaches the specified “off” value (20°C).

MOSFET

Foam Insulation Board used for Box

Structure

Heater Circuit

Diagram

Expected Results:

• Verification of nominal subsystem-subsystem interaction through log of command out and telemetry in to the Flight Compute Element

• Thermistor Temperature

• Heater ON/OFF

• PMAD Board Voltage

• Image acquisition at altitude

• Verification of camera link to Flight Compute Element

• PR Value!

• Verification of on-board image processing routine on Flight Compute Element

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Demonstration:

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Power on the Power Management & Distribution circuit

Telemetry readout and heater switching on the Thermal Control subsystem