1. MAGGEX FRR Evan Anzalone Louisiana State University 5/23/2005 NSBF, Palestine, TX

2. Purpose Measure magnitude of the geomagnetic field as a function of altitude Check accuracy of World Magnetic Model over a large altitude range Look for spatial and temporal variations in magnetic field

3. Expected Field Courtesy: IGRF Model

4. Payload Overview Based on standard BalloonSat package: –BasicStamp 2p24, 4 channel ADC, RTC, 256kbit EEPROM –Each reading is 80 bits –Take reading every 5 seconds Outer box: 18 x 15 x 10.5 cm Batteries: 8 x 1.5 V e 2 Lithium Batteries 3000mAh –2 for RTC backup, 6 for electronics Power needed: 60 mA ~4 hours, 240 mAh Weight: 423.7 g

5. Sensor Package Donated by Precision Navigation Corp. PNI ASIC 11096 Driver, Sen-L Sensor –low power, temperature-independent measurements, resolution used ~.042 mG/count –Driver returns 16 bit signed integer “count” of change in frequency between forward and reverse bias frequency measurements –3 sensors arranged orthogonal

6. Operations Design Read time from RTC Read measurement of temperature from sensors on voltage regulator Individually send commands to ASIC to take three orthogonal field measurements Store all information to EEPROM Pause until next reading

7. Certifications Vacuum: –Stable operation independent of pressure Temperature: –Readings independent of temperature change –Insulation proven to keep temperature at operation level Electronics/Software: –Proven operation in lab, electronics/software at very mature stage of use

8. Interference Testing Other BalloonSat’s –No effect at inter-payload distance Payload Electronics –Small effect, ~.1 mG, within error, steady GPS Beacons –No effect due to radio beacon, even when antenna placed near to sensor

9. Data Analysis Procedure Offload data from EEPROM to PC Obtain location data Put location data into modified World Magnetic Model Code Compare Model to actual readings to see local variations

10. Final Preparations Install fresh batteries Seal inner package Paint outer package Seal outer package (near time of attachment to flight-line)