Louisiana State University (LSU)NSF PACER ProgramPhysics & Aerospace Catalyst Experiences

A. M. Espinal Mena, V.Gónzalez Nadal, J. Díaz ValerioFaculty Advisor: Dr. H. Vo

Aerospace Balloon Imaging Testing with Accelerometer (ABITA) Experiments

The Interamerican Geospace Research Experiments (TIGRE) Team

Preliminary Design Review (PDR)

6/30/2008

Outline

Goals, Objectives & Requirements Payload Design Payload Development Plan Payload Construction Plan Project Management Master Schedule Risk Management and Contingency

Mission

To determine balloon dynamics.

Reference: BEXUS 5 Experiment (Altitude Sensing and Determination System)

Scientific Objectives

Obtain images of the surrounding environment Create a model of the balloon movements Determine rotational & translational movement

Technical Objectives

Develop a payload less or equal to 500 g Have a maximum cost of $ 500 Collect data for about 4 hours balloon flight

Science Background

Reference: Lyndon State College, Department of Meteorology

Scientific Requirements

Record the flight time of payload

Observe the surrounding environment of the balloon

Record outside temperature

 Obtain the vector acceleration of the balloon payload

Know the rate of tilt change and its relationship with the acceleration

Technical Requirements

Require to have a real time clock on board Include video camera capable of recording 4 hours Include a three axis accelerometer to record

vibration/shock Compare data at high rates Record tilt of payload

Electrical Design

ADXL330 Three Axis Accelerometer

Digital Video Camera

1N4001 Diode Temperature Sensor

Control Electronics

Power Supply

Power Budget

Component Current (mA)

BalloonSat ~56

3 Buffers ~3 (1 each)

Three axis accelerometer (ADXL330)

~0.32

Temperature Sensor (Diode) ~1

Voltage to Frequency Converter

~ 5 (1.67 each)

Total Current ~64.32

Power Budget

Estimated Requirement : 257.28 mA-hour

The 9V battery will supply: 750 mA-hour at -20 C Note: The camera has its on power supply & also its own

memory

Mechanical Design

General Design

The “Giammanco” Model?Foam core construction.Component placement and its importance.Mechanical design and construction.

External Structure

Front, Cross Section and Bottom View of Model

Multi-View Enclosure Model

Internal Structure

Multi-View Internal Model

Front, Cross Section and Hidden Lines View of Model

New Design

Advantages:Components are placed in modular spaces.Physically smaller than original design.Structurally stronger.Ease of access to components.

Redesigned Enclosure

The above picture depicts the payloads enclosure, insert and lid.

Multi-View of External Design

Redesigned Enclosure

Multi-View of Assembled Model

Picture above depicts assembled enclosure, open and sectioned views.

So why a new design?

New Design

Disadvantages:Still in the drawing board.Design might be heavier than original.Complexity of construction.

Assembly and Disassembly

Weight budget

Component: Weight:

BalloonSat Board 67g

Video Camera 42.3g

Accelerometer ~19g

Temperature Sensor ~2g

Conditioning Circuitry ~30g

Camera Power Supply 48.6g

Electronics Power Supply 46.6g

Payload Enclosure ~150g

Cables and Connectors ~40g

Total: ~447.5g

Payload Development

Phases are required to build our payload:• Electronics design.• Software design and testing.• Mechanical design and construction.• Assembly, testing and modification to the payload.

Payload Fabrication

The order of fabrication is as follows:• Ordering of components needed.• Component prototyping and functionality assurance.• Mounting components onto PCBs.• Construction of payload enclosure.• Testing and certifying that all components work together.

Software Design

Software RequirementsControl Instruments

- Time Stamp

- Temperature Sensor

- Accelerometer

- Digital Camera

Calibrate DataAnalyze DataInterpret Data

Data Format and Storage

EEPROM will have to store 13 bytes per minute for 4 hours from the

4 * 60 minutes = 240 minutes13 bytes * 240 minutes = 3, 120 bytes for the whole

flight

Data Format and StorageByte Description

1 Time Stamp: hour

2 Time Stamp: minute

3 Time Stamp: second

4 Temperature

5 Accelerometer: X axis Max

6 Accelerometer: X axis Min

7 Accelerometer: X axis Average

8 Accelerometer: Y axis Max

9 Accelerometer: Y axis Min

10 Accelerometer: Y axis Average

11 Accelerometer: Z axis Max

12 Accelerometer: Z axis Min

13 Accelerometer: Z axis Average

Software: Pre- Flight

Software:During Flight

• Main loop: After every minute

Software:During Flight• The accelerometer Loop: If one minute has not passed

Software: Post- Flight

Data Analysis Plan

• Level 0: Raw Data - Data downloaded to BASIC STAMP and saved using Term 232

• Level 1: Calibrated Data- Convert digital values into physical quantity

• Level 2: Analysis-Data interpreted using Graphing Analysis -Frame grabber to analyze video image

-Accelerometer’s frequency using Spectrogram

Work Breakdown Schedule

Risk Management & Contingency

Management Plan

Team TIGRE member roles:

-Ana M. Espinal Mena: Electronics design.

-Jonathan Diaz Valerio: Mechanical design & fabrication.

- Victoria Gonzalez Nadal: Software Design and implementation.

Team TIGRE webpage: www.pjarea.com/wiki