PACER Summer ProgramHigh-Altitude Thermodynamics Profile and Clarity Experiment

(HATPaC)

Johnte Bass, Herman Neal, Matthew WareJohnte Bass, Herman Neal, Matthew Ware

Mission Goal

Investigate the temperature, pressure, Investigate the temperature, pressure, density and clarity as a function of altitude density and clarity as a function of altitude up to about 100,000 feet in order to study up to about 100,000 feet in order to study layering in Earth’s lower atmosphere. layering in Earth’s lower atmosphere.

Science Background The payload will ascend through the

troposphere, the tropopause, and into the stratosphere to the upper boundary of the ozone maximum.

This figure represents a typical temperature profile of the layers of the atmosphere. However, the specific profile depends on location, particularly the latitude. There is also a seasonal variation with the tropopause at higher altitudes in summer at latitudes smaller than 60°.

The HATPaC experiment will measure the profile over East Central Texas (35° latitude) in midsummer.

Science Background (continued) The tropopause is characterized

by a region several kilometers thick where the temperature is relatively constant. High altitude sounding measurements indicates that temperature over 2 km altitude range varies 3 °C or less.

This figure shows the pressure and density profiles as determined by the NRLMSISE Standard Atmosphere Model.

The atmosphere may be considered as an ideal gas. The ideal gas law may be used to calculate the density from measurements of pressure and temperature: = MP/RT.

Science Objectives1.1. Identify the zones of the Earth’s lower atmosphere.Identify the zones of the Earth’s lower atmosphere.2.2. Determine the altitude of the tropopause.Determine the altitude of the tropopause.3.3. Develop a temperature profile of the atmosphere.Develop a temperature profile of the atmosphere.4.4. Develop a pressure profile of the atmosphere.Develop a pressure profile of the atmosphere.5.5. Develop a density profile of the atmosphere.Develop a density profile of the atmosphere.6.6. Qualitatively evaluate atmospheric clarity as altitude Qualitatively evaluate atmospheric clarity as altitude

varies.varies.7.7. Compare accepted models of the atmosphere to Compare accepted models of the atmosphere to

measurements.measurements.8.8. PresentPresent findings findings

Science Requirements

Make measurements every 15 seconds.Make measurements every 15 seconds. Calculate density within 5% uncertainty which includes:Calculate density within 5% uncertainty which includes:

Measure temperature to within 1 °C (0.5% at the tropopause).

Measure pressure to which 1 mbar (5% at the tropopause).

Determine the altitude to within 100 meters. Take photographs during ascent and descent every 15

seconds up to an altitude of 100,000 feet.

Technical Objectives1.1. Build and fly a payload and retrieve the data.Build and fly a payload and retrieve the data.2.2. Measure temperature over the range -80 ˚C ≤ Measure temperature over the range -80 ˚C ≤ TT ≤ 40 ˚C. ≤ 40 ˚C.3.3. Measure pressure over the range 5 mbar ≤ Measure pressure over the range 5 mbar ≤ PP ≤ 1000 mbar. ≤ 1000 mbar.4.4. Calculate the atmospheric density using the ideal gas law.Calculate the atmospheric density using the ideal gas law.5.5. Take photographs of the external environment using two onboard Take photographs of the external environment using two onboard

cameras for the duration of the flight. The two cameras will provide an cameras for the duration of the flight. The two cameras will provide an overlapping field of view from 10˚ above the horizon to 60˚ below the overlapping field of view from 10˚ above the horizon to 60˚ below the horizon.horizon.

6.6. Store thermodynamic data in memory contained within the payload Store thermodynamic data in memory contained within the payload control computer and photographic images in flash memory within the control computer and photographic images in flash memory within the cameras.cameras.

7.7. Correlate payload data with mission telemetry data to determine the Correlate payload data with mission telemetry data to determine the altitude of each measurement.altitude of each measurement.

Technical Requirements Payload must remain intact from launch to recovery.Payload must remain intact from launch to recovery. Power system must operate over the temperature range -80 °C ≤ Power system must operate over the temperature range -80 °C ≤ TT ≤ 40 °C with ≤ 40 °C with

the capacity to power the BalloonSat, sensors, and data archive for the duration of the capacity to power the BalloonSat, sensors, and data archive for the duration of the flight.the flight.

Temperature sensor able to measure over the range -80 °C ≤ Temperature sensor able to measure over the range -80 °C ≤ TT ≤ 40 °C. ≤ 40 °C. Pressure sensor able to measure over the range 5 mbar ≤ Pressure sensor able to measure over the range 5 mbar ≤ PP ≤ 1000 mbar. ≤ 1000 mbar. Camera able to operate over the temperature range -80 °C ≤ Camera able to operate over the temperature range -80 °C ≤ TT ≤ 40 °C and ≤ 40 °C and

pressure range 5 mbar ≤ pressure range 5 mbar ≤ PP ≤ 1000 mbar. ≤ 1000 mbar. Record time to 15 second accuracy.Record time to 15 second accuracy. Data archive system with the capacity to store measurements by the sensors and Data archive system with the capacity to store measurements by the sensors and

real time clock for the duration of the flight (approximately 750 data records)real time clock for the duration of the flight (approximately 750 data records) Photograph storage media with the capacity to store about 1500 1.3 megapixel Photograph storage media with the capacity to store about 1500 1.3 megapixel

(1600 (1600 1200 pixels) images. 1200 pixels) images. Ground system which can download, analyze, and graphically display payload Ground system which can download, analyze, and graphically display payload

measurements.measurements.

Sensor Subsystem Schematic

Power Subsystem Schematic

Data Storage Format

Name Bytes

Sequence No. 2

Hour 1

Minute 1

Seconds 1

Temperature Outside1 1

Temperature Outside2 1

Temperature Inside 1

Pressure 1

Flight Software Flow Chart

Readoutside

temperature

ReadDate

Incrementsequence #

Store EEPROMaddress in RAM

on RTC

B

Write values toEEPROM and

increment addr.after each write

ReadHour

ReadMinute

ReadSecond

ReadPressure

Read insidetemperature

B

NO

YES

Wait fortime slot

Takepictures

Store hoursand minutes

in RAM

Elapsedtime >4hrs?

Tests if 10addrs. inEEPROM

=FF

A

A

Power upcamera

Verify RTC

Initializevariables

Define I/Opins

Initializesequence #

Tests if 10addrs. inEEPROM

=FF

Start

NO

YES

Read RTCRAM formagic #

Get launch timeand calculateelapsed time

InitializeEEPROMaddress

YES

NO

Payload Construction

The Pacer payload is constructed using a material The Pacer payload is constructed using a material called Foamular.called Foamular.

This type of material can withstand extreme This type of material can withstand extreme temperatures, pressure and shock from the landing temperatures, pressure and shock from the landing of the payload.of the payload.

The material that will reinforce the payload is silver The material that will reinforce the payload is silver mylar which can withstand cold temperatures and mylar which can withstand cold temperatures and also work as a good insulator.also work as a good insulator.

The plywood that the camera are on is stuck The plywood that the camera are on is stuck together with the cameras using Gorilla Glue. together with the cameras using Gorilla Glue.

Mechanical Design

Closed Capsule (Right Side View)Closed Capsule (Right Side View)

Closed Capsule (Left Side View)Closed Capsule (Left Side View)

Mechanical Design (continued)

Lid (Top View)Lid (Top View)

Lid (Side View)Lid (Side View)

Mechanical Design (continued)

Capsule Interior w/o BalloonSatCapsule Interior w/o BalloonSat

Capsule Interior w/BalloonSatCapsule Interior w/BalloonSat

Thermal Test

Shock Test

Power BudgetComponentComponent Voltage (V)Voltage (V) Current (mA)Current (mA) Power (mW)Power (mW) Duty Cycle (%)Duty Cycle (%)

BalloonSatBalloonSat

SubsystemSubsystem

8–128–12 6060 720720 100100

Data ArchiveData Archive On BalloonSatOn BalloonSat On BalloonSatOn BalloonSat On BalloonSatOn BalloonSat 100100

Temperature Temperature SensorsSensors

8–128–12 88 9696 100100

Pressure SensorPressure Sensor 8–128–12 5 5 6060 100100

RelaysRelays 55 2424 120120 33

Cameras-idlingCameras-idling

(each camera)(each camera)

22 200200 400400 8585

Cameras-during Cameras-during exposureexposure

(each camera)(each camera)

22 320320 640640 1515

Weight Budget

ComponentsComponents Weight (grams)Weight (grams)

CaseCase 172172

Two Exterior Temperature SensorsTwo Exterior Temperature Sensors 1111

Pressure SensorPressure Sensor Included on DaughtercardIncluded on Daughtercard

Batteries for CameraBatteries for Camera 8787

Batteries for BalloonSatBatteries for BalloonSat 8585

Two CamerasTwo Cameras 7373

Power ConnectorsPower Connectors 88

BalloonSat and DaughtercardBalloonSat and Daughtercard 149149

TotalTotal 585585

Pacer Flight Pressure vs. Altitude

Pressure Sounding Profile

Pressure Profile

Temperature Sounding Data

Inside Temperature Profile

Outside Temperature Profile

Temperature Sensor Comparison

Density Profile

At Peak

Retrieval

PACER HATPaC Flight Badge Combination of the US Army Combination of the US Army

93rd Infantry Division patch 93rd Infantry Division patch and GSU logo.and GSU logo.

The 93rd was to fight in World The 93rd was to fight in World War I, but was sent to France to War I, but was sent to France to help the French Army.help the French Army.

The object covering the GSU The object covering the GSU logo is the French steel helmet.logo is the French steel helmet.

The 93rd’s Division badge has The 93rd’s Division badge has the same colors as GSU. the same colors as GSU. Herman Neal is an US Army Herman Neal is an US Army veteran. Dr. Ware’s father veteran. Dr. Ware’s father served in the Infantry in France served in the Infantry in France during World War I.during World War I.

Acknowledgements

PACERPACER LaSPACE, the Louisiana Space Grant ConsortiumLaSPACE, the Louisiana Space Grant Consortium National Science FoundationNational Science Foundation NASA Columbia Scientific Balloon FacilityNASA Columbia Scientific Balloon Facility Louisiana State University-Baton RougeLouisiana State University-Baton Rouge