PACER Summer Program
Preliminary Design Review Document
For the
Atmospheric Thermodynamics Profile and Clarity Experiment
By
Team PACER-GSU
Prepared by:
Johnte Bass Date
Herman Neal Date
Matthew Ware Date
Team Member (replace with name) Date
Team Member (replace with name) Date
Submitted:
Reviewed:
Revised:
Approved:
Institution Signoff (replace with name) Date
Institution Signoff (replace with name) Date
LA SPACE Signoff Date
Change Information Page
Title: PDR Document for Atmospheric Thermodynamics Profile and Clarity Experiment
Date: 06/29/2007
List of Affected Pages
Page Number
/ Issue / DateTBD
Number
/ Section / Description / DateCreated / Date Resolved
Open payload lid. TBD / 6/29
Insert fresh batteries into their designated locations / 6/29
Attach a serial cable from a laptop computer / 6/29
Boot the computer and start pre-launch software. / 6/29
Set the real time clock and initialize the EEPROM data archive system / 6/29
Disconnect the serial cable. / 6/29
Close and secure the payload lid. TBD / 6/29
Status of TBDs
TABLE OF CONTENTS
Cover i
Change Information Page ii
Status of TBDs iii
Table of Contents iv
List of Figures v
List of Tables vi
1.0 Document Purpose 1
1.1 Document Scope 1
1.2 Change Control and Update Procedures 1
2.0 Reference Documents 2
3.0 Goals, Objectives, Requirements 3
3.1 Mission Goal 3
3.2 Objectives 3
3.3 Science Background and Requirements 3
3.4 Technical Background and Requirements 3
4.0 Payload Design 4
4.1 Principle of Operation 4
4.2 System Design 4
4.3 Electrical Design 4
4.3 Software Design 4
4.4 Thermal Design 4
4.5 Mechanical Design 4
5.0 Payload Development Plan 5
6.0 Payload Construction Plan 6
6.1 Hardware Fabrication and Testing 6
6.2 Integration Plan 6
6.3 Software Implementation and Verification 6
6.4 Flight Certification Testing 6
7.0 Mission Operations 7
7.1 Pre-Launch Requirements and Operations 7
7.2 Flight Requirements and Operations 7
7.3 Data Acquisition and Analysis Plan 7
8.0 Project Management 8
8.1 Organization and Responsibilities 8
8.2 Configuration Management Plan 8
8.3 Interface Control 8
9.0 Master Budget 9
9.1 Expenditure Plan 9
9.2 Material Acquisition Plan 9
10.0 Risk Management and Contingency 10
11.0 Glossary 11
LIST OF FIGURES
1. Figure on expected science results 2
2. Block diagram of payload systems 4
3. Schematic of sensor electronics 5
4. Schematic of control electronics 6
5. Schematics of power system 6
6. Flight software flow chart 7
7. Ground software flow chart 11
8.. Project organization chart 11
LIST OF TABLES
1. Goals versus measurement traceability matrix 5
2. Power budget table 6
3. Data format and storage 7
4. Weight budget table 9
5. Flight certification check list 10
6. Organization and Responsibilities 11
7. Project budget 12
i
Team PACER-GSU PDR v1.0
1.0 Document Purpose
This document describes the preliminary design for the Atmospheric Thermodynamics Profile and Clarity experiment by Team PACER-GSU for the PACER Summer Program. It fulfills part of the PACER Summer Program Project requirements for the Preliminary Design Review (PDR) to be held June 29, 2007.
1.1 Document Scope
This PDR document specifies the scientific purpose and requirements for the Atmospheric Thermodynamics Profile and Clarity experiment and provides a guideline for the development, operation and cost of this payload under the PACER Project. The document includes details of the payload design, fabrication, integration, testing, flight operation, and data analysis. In addition, project management, timelines, work breakdown, expenditures and risk management is discussed. Finally, the designs and plans presented here are preliminary and will be finalized at the time of the Critical Design Review (CDR).
1.2 Change Control and Update Procedures
Changes to this PDR document shall only be made after approval by designated representatives from Team PACER-GSU and the PACER Institution Representative. Document change requests should be sent to Team members, the PACER Institution Representative and the PACER Project.
2.0 Reference Documents
[Include and number the documents that provide background or supporting information and include in the write-up as references.]
3.0 Goals, Objectives, Requirements
3.1 Mission Goal
Investigate the temperature, pressure, density and clarity as a function of altitude up to about 100,000 feet in order to study layering in Earth’s lower atmosphere.
3.2 Objectives
3.2.1 Science Objectives
1. Identify the zones of the Earth’s lower atmosphere.
2. Determine the altitude of the tropopause.
3. Develop a temperature profile of the atmosphere.
4. Develop a pressure profile of the atmosphere.
5. Develop a density profile of the atmosphere.
6. Develop a reflectance profile of the atmosphere.
7. Compare models of the atmosphere to measurements.
8. Present findings.
3.2.2 Technical Objectives
1. Build and fly a payload and retrieve the data.
2. Measure temperature over the range -80 ˚C ≤ T ≤ 40 ˚C.
3. Measure pressure over the range 5 mbar ≤ P ≤ 1000 mbar.
4. Calculate the atmospheric density using the ideal gas law.
5. Take photographs of the external environment using an onboard camera for the duration of the flight.
6. Store thermodynamic and photographic data onboard the payload.
7. Correlate payload data with mission telemetry data to determine the altitude of each measurement.
3.3 Science Background and Requirements
3.3.1 Science Background
This payload will ascend through the troposphere, the tropopause, and into the stratosphere to the upper boundary of the ozone maximum.
The word troposphere comes from tropein, meaning to turn or change. All of the earth's weather occurs in the troposphere. It extends from the earth's surface to an average of 12 km (7 miles). The pressure ranges from 1000 to 200 milliards. The temperature generally decreases with increasing height up to the tropopause. The temperature averages 15°C (59°F) near the surface and -57°C (-71°F) at the tropopause. The layer ends at the point where temperature no longer varies with height. This area, known as the tropopause, marks the transition to the stratosphere.
3.3.2 Science Requirements
1. Measure temperature with TBD accuracy.
2. Measure pressure with TBD accuracy.
3. Calculate density with TBD accuracy.
4. Make measurements with TBD frequency.
5. Determine altitude with TBD accuracy.
6. Take photographs up to an altitude of 100,000 feet.
3.4 Technical Background and Requirements
3.4.1 Technical Background
The experiment will be performed by an instrument payload which will be secured between two strings beneath a latex helium sounding balloon. The experiment will operate for the duration of the flight which will be approximately three hours. The payload will be self-contained with respect to electric power, computer control, and data storage. It will rely on a GPS beacon located in another payload on the flight string for latitude, longitude, and altitude.
The payload will take measurements of ambient temperature and pressure. An onboard camera will photograph the environment. All measurements taken with onboard instrumentation will be time stamped. The time stamp will allow payload-based measurements to be correlated with GPS data in post-flight data analysis.
Temperature will be measured using an Analog Devices AD22100 monolithic temperature sensor with on-chip signal processing. The temperature sensor is powered by 5 V dc. Pressure will be measured by an ICSensors Model 1210 temperature compensated piezoresistive silicon pressure sensor. The pressure sensor is powered by 1.5 mA. These measurements will be made under the control of a BASIC Stamp microprocessor and archived in EEPROM nonvolatile memory. These devices are integrated with the BallonSat and share its power. Power for the BalloonSat will be provided by a 9 V lithium battery. Photographs will be taken with a VistaQuest VQ1005 digital camera triggered by the BASIC Stamp and stored on a 512 MB Secure Digital flash card. The camera will be powered by a separate 1.5 V lithium battery. All measurements will be time-stamped using a real time clock onboard the BalloonSat.
3.4.2 Technical Requirements
1. Payload must remain intact from launch to recovery.
2. Power system must survive temperatures over the range -80 ˚C ≤ T ≤ 40 ˚C.
3. Temperature sensor able to measure over the range -80 ˚C ≤ T ≤ 40 ˚C.
4. Pressure sensor able to measure over the range 5 mbar ≤ P ≤ 1000 mbar.
5. Camera able to operate over the temperature range -80 ˚C ≤ T ≤ 40 ˚C and pressure range 5 mbar ≤ P ≤ 1000 mbar.
6. Photograph storage medium with the capacity to store TBD high-resolution pictures.
7. Record time to TBD accuracy.
4.0 Payload Design
The payload will consist of a power supply connected to the BalloonSat and external sensors. The payload will have a data converter, a light control unit, a data storage unit, a sensor to measure the temperature, a sensor to measure the pressure, and a camera to take photographs of the atmosphere.
4.1 Principle of Operation
Temperature will be measured using an Analog Devices AD22100 monolithic temperature sensor with on-chip signal conditioning.
Pressure will be measured using an ICSensors Model 1210 temperature compensated piezoresistive silicon pressure sensor.
Photographs will be taken using a VistaQuest VQ1005 digital camera. They will be stored on a 512 MB Secure Digital flash memory card attached to the camera.
The payload will be controlled by a BASIC Stamp embedded microprocessor. The BASIC Stamp will convert all payload-collected thermodynamic and temporal data to digital form and archive it in EEPROM non-volatile memory.
4.1 System Design
4.1.1 Functional Components
Mechanical. The container will hold all instruments for the payload. It must secure each instrument and protect it against the shocks of the ascent and landing.
Thermal. It will also provide the thermal insulation for the instruments which will protect them from the cold temperatures of the upper troposphere, tropopause, and lower stratosphere. The thermal system is the insulating shearing used to construct the box and the heat generated by the electrical components within the payload during operation.
Power. Batteries must provide sufficient power for the duration of the flight to power the controller, all of the instruments, and the data archive.
Sensors. A temperature sensor will measure the ambient temperature. A pressure sensor will measure the ambient pressure. A digital camera will photograph the environment outside the payload.
Processor. A BASIC Stamp processor is integrated with the BalloonSat.
Data Archive. An EEPROM onboard the BalloonSat archives data collected by the temperature and pressure sensors and real time clock. A 512 MB Secure Digital card is inserted into the camera’s integrated SD card slot to store the photographs taken by the camera.
4.1.2 Traceability
Component / Functional Requirements / Implemented InPayload Capsule / Keep the payload intact from launch to recovery / Test payload box ability to withhold under a vacuum, in dry ice, and drop from a certain height
Battery / Supply the payload wit 9 volts of power. / Run a sample program and verify that every component receives power
Temperature Sensor / Measures the temperature outside of the payload / Run a sample program and measure temperature
Pressure Sensor / Measures the temperature outside of the payload / Run a sample program and measure pressure
Camera / Take photographs up to an altitude of 100,000 feet / Test cameras ability to operate at low temperatures and under pressure
Basic Stamp / Converts data into numerical values/ controls the sensors/ powers the EEPROM / Run a sample program and verify its control over other components under certain conditions
EEPROM / Collects data from BASIC Stamp / Run a sample program and verify its ability to store data under certain conditions
Real Time Clock / Keeps time during payload flight / Run a sample program and verify its ability to maintain time under certain conditions
4.2 Electrical Design
4.2.1 Sensors
Temperature will be measured using an Analog Devices AD22100 monolithic temperature sensor with on-chip signal conditioning.
Pressure will be measured using an ICSensors Model 1210 temperature compensated piezoresistive silicon pressure sensor.
Photographs will be taken using a VistaQuest VQ1005 digital camera. They will be stored on a 512 MB Secure Digital flash memory card attached to the camera.
4.2.2 Sensor Interfacing
The sensor subsystem will receive power from the power supply as shown earlier. The power is then distributed when the temperature and pressure sensors. The camera however has its own power source and its information is converted to digital by way of the SD memory card that id attached to it. The different signals from the other sensors will be converted to digital information by way of the ADC on the Processor.
4.2.3 Control Electronics
The flight control unit is the BalloonSat. It includes a data storage chip(EEPROM), the digital converter(ADC), the real time clock, and the back-up internal temperature sensor.
4.2.4 Power Supply
A schematic of the system is shown at the right. It includes a thermodynamic instrument subsystem to power everything except the camera and its picture archive. The power subsystem for the thermodynamic instruments will be based on a 9-12 volt lithium battery. During laboratory development, power will be supplied by a Heathkit IP-2718 power supply.
The camera power subsystem will be powered by a 1.5 V lithium C-cell during flight. During laboratory development, power will be supplied by a 1.5 V alkaline AA cell. The camera will need no voltage conversion because it designed to operate on 1.5 V power. It will, however, require a modification to use the C-cell because its battery holder is designed for an AA cell.
4.2.5 Power Budget
The components of the payload devoted to acquisition of thermodynamic data will require a separate power source from the digital camera. Therefore, their power budgets have been separated as shown in the tables on the right.