Full Mission Simulation Test Report

1. Full Mission Simulation Test Report RocketSat CU Boulder 5-15-2010

2. Mission Overview • Goal is to characterize atmosphere for amount of meteoric smoke particles • Looking for numerical density/altitude and charge • Particles are being studied by many scientists for effects on upper atmosphere • Possible connection to PMCs • Models predicting global shift of these particles, not proven • Have been measured <10 times

3. Design Overview • Half canister, sharing with VT • Two Graphite Patch Detectors (mounted on skin of rocket) • 5 Electronics Boards • AVR: temperature, pressure, xyz accelerations • SCIENCE: gyroscopes (pitch, yaw, roll) • CVA: 2, convert current input from detectors to voltage • MEPO: takes voltage from CVAs and stores Colorado Space Grant Consortium RocketSat VI

4. Changes to System • Electronics changes • Added resistors to AVR • Added transmission gate due to bus contention • Allowed for successful read/write from flash to RealTerm • Structures changes • Need aluminum boxes around amplifiers to reduce noise and interference

5. New Design Final design Integrated payload without AVR, SCIENCE, MEPO New boxes for CVAs Colorado Space Grant Consortium RocketSat VI

6. PCBs in Current State AVR SCIENCE MEPO Colorado Space Grant Consortium RocketSat VI

7. CVA Testing • Tested amplifiers in aluminum box to check noise reduction • Metal box acts as Faraday Cage to prevent exterior signals from being amplified (overshadows data) Colorado Space Grant Consortium RocketSat VI

8. CVA Testing Noise Results • Noise reduced to 200mV as opposed to 2V 60Hz power signal • Allowed for CVA calibration with inputs Colorado Space Grant Consortium RocketSat VI

9. CVA Testing • CVAs were calibrated to determine relationship between input current and output voltage • Tested each CVA in box with power supply, measured output voltage • Inputted a DC voltage through a 1GΩ resistor • From Ohm’s Law, knew that 1V through 1GΩ resistor  1 nA of current Colorado Space Grant Consortium RocketSat VI

10. CVA Testing Results: 2.5V Bias on Input and Output Colorado Space Grant Consortium RocketSat VI

11. CVA Testing Results: 2.5V Bias on Input Only Colorado Space Grant Consortium RocketSat VI

12. Detector Functionality Testing • Bell Jar Results – reduced pressure not significant enough to produce valid results • Instead, connected detector to amplifiers, pointed at various sources, touched, to look for changes in voltage outputs Colorado Space Grant Consortium RocketSat VI

13. Detector Functionality Results • Ambient signal from detector • without this signal, output from CVA sits at ~5V • Pointing detector at the wall, computer, touching it, yielded different voltages Colorado Space Grant Consortium RocketSat VI

14. Integrated System Test • Tested MEPO with CVA and detector • Read results into RealTerm • Testing with both bias types • MEPO can provide 15V rails Colorado Space Grant Consortium RocketSat VI

15. CVA #61 Results (I/O Bias) Colorado Space Grant Consortium RocketSat VI

16. SCIENCE Board Testing • Outputs from all sensors the same • Results imply incorrect sample rate or other code issues • RealTerm readouts show variation in voltage output Colorado Space Grant Consortium RocketSat VI

17. AVR Board Testing • Flight code has worked on AVR with sampling, read/write • Flash is writing, working with data utility Colorado Space Grant Consortium RocketSat VI

18. Results • Detectors and CVAs fully functional • Flash memories are working • Structure nearing completion • Flight code nearing completion Colorado Space Grant Consortium RocketSat VI

19. Action Items • Can launch with current code, data would be full of error • Sample rates • Max sample rate on MEPO is 1k, need at least 2k to sample detectors quickly enough • Need to sample gyros at 330Hz each, right now max is 250Hz (1000Hz/ 4 sensors) • Two options for increasing sample rate • Software fix – change internal AVR sample rate, adjust timing and clocks in all code • Hardware fix – change microcontroller to ATXmega256 • Two SPI buses, faster internal sample rate would eliminate necessity of external ADCs and transmission gates

20. Action Items • Spin Test • Lockheed Martin 3 axis spin table • Shock Test • Dropping fully integrated stack for deceleration • Checking power connections • Vibe Test • ITL Lab • Preliminary vibe to check ballast weight stability Colorado Space Grant Consortium RocketSat VI

21. Lessons Learned • Schedule • Try to build-up first rev of boards before Christmas • Test in small sections before integrating, including on the PCBs • Do your research thoroughly to minimize last minute changes

22. Backup Slides

23. FBD: Full System Rocket 9V G-switch Z- accelerometer Command Line AVR Dust Particle Detectors Latch LEDEX CVA XY acc Temp/Press SCIENCE gyros MEPO CVA Dust Particle Detectors Latch Latch AD977 9V 9V Canister Write Enable Trigger Colorado Space Grant Consortium RocketSat VI

24. FBD: Boards 9V Power G-Switch RBF (Wallops) Temperature Sensor 3.3V Voltage regulator Microcontroller Pressure Sensor 5V Voltage regulator ADC 3 axis High range Accelerometers Level Shifter 3 axis Low Range Accelerometers AVR Board Flash Memory MEPO board Flash memory Data Gyroscope Pitch and Yaw ADC 3.3V Buffer 9V Level Shifter Gyroscope Pitch and roll 5V Microcontroller +15V Science Board Colorado Space Grant Consortium RocketSat VI