Stratospheric Ozone Experiment 26 May 2005 Donald Swart Christopher Barber Michael O’Leary Gregg Ridlon Robert Schefferstein

Goals Measure UVB and UVC attenuation through the stratosphere Measure UVB and UVC attenuation through the stratosphere Approximate the thickness of the ozone using attenuation data Approximate the thickness of the ozone using attenuation data “Map” the ozone layer “Map” the ozone layer Measure pressure as a function of altitude Measure pressure as a function of altitude

Overview of Results UV Data: Uncollected Cause: Programming Error Pressure Data: Collected successfully

UV Data Circuit retested on the ground successfully Circuit retested on the ground successfully Programming error caused our UV readout to come from an incorrect ADC pin. Programming error caused our UV readout to come from an incorrect ADC pin. Four ADC pins, only three were used (ch 0,1,3), and our data was recorded from channel 2, which had no signal being fed into it Four ADC pins, only three were used (ch 0,1,3), and our data was recorded from channel 2, which had no signal being fed into it

Pressure Data Pressure measurements were very successful in showing the variation of pressure as a function altitude. Pressure measurements were very successful in showing the variation of pressure as a function altitude. After correcting the zero offset for our circuitry our pressure graph looks accurate, within 17 HPa of the known ground pressure at launch. After correcting the zero offset for our circuitry our pressure graph looks accurate, within 17 HPa of the known ground pressure at launch. Taking this error into account the lowest pressure sustained by our payloads was HPa ± 17 HPa. Taking this error into account the lowest pressure sustained by our payloads was HPa ± 17 HPa.

Pressure Uses Adding temperature data to our pressure data (thanks go to LA Tech) we were able to calculate several other pieces of data: Adding temperature data to our pressure data (thanks go to LA Tech) we were able to calculate several other pieces of data: Air densityAir density Drag ForcesDrag Forces Potential TorquePotential Torque Velocity data was inferred from altitude and time stamp data. Velocity data was inferred from altitude and time stamp data.

Pressure and Altitude vs. Time

Velocity and Density vs Time

Velocity and Altitude vs. Time

Analysis Sharp Change in Velocity at UT 15:34 Sharp Change in Velocity at UT 15:34 Probable time of SU payload lossProbable time of SU payload loss Highest “jerk”Highest “jerk” Greatest potential torque (assuming payloads weren’t falling “ducks in a row”)Greatest potential torque (assuming payloads weren’t falling “ducks in a row”) Time and altitude correspond to the location of the tropopause; lowest temperatures and most brittle state for most plastics Time and altitude correspond to the location of the tropopause; lowest temperatures and most brittle state for most plastics

Analysis cont. Early speculations stated payload possibly lost at tropopause; collected data reinforces original theories. Early speculations stated payload possibly lost at tropopause; collected data reinforces original theories. Velocity Data too inaccurate to reliably calculate drag Velocity Data too inaccurate to reliably calculate drag Parachute behavior also unknown, only speculatedParachute behavior also unknown, only speculated

Improve Earlier testing techniquesEarlier testing techniques Labeling Programs with proper version numbersLabeling Programs with proper version numbers Organized checklist of final assembly stepsOrganized checklist of final assembly steps Periodic review/revising of checklistsPeriodic review/revising of checklists Debug ProcessesDebug Processes TeamworkTeamwork Time ManagementTime Management

Sustain Circuit Design Circuit Design Thermal Design Thermal Design Finishing the payload despite setbacks Finishing the payload despite setbacks Background Research Background Research

Acknowlegments Lawrence Blanchard Lawrence Blanchard Dr. Kevin Stokes Dr. Kevin Stokes Lester Langford and Stennis Space Center Lester Langford and Stennis Space Center NSBF and NASA NSBF and NASA LA Tech LA Tech LA ACES Panel LA ACES Panel