WVU RockSat 2010: Atmospheric & Plasma Physics Experiments

1. WVU Returns to RockSat 2010: A Research and Education Project West Virginia University Rocketeers Student team: N. Barnett, R. Baylor, L. Bowman, M. Gramlich, C. Griffith, S. Majstorovic, D. Parks, B. Pitzer, K. Tewey, E. Wolfe Faculty advisors: Y. Gu, D.J. Pisano, D. Vassiliadis June 2010

2. Mission Statement • The mission of WVU RockSat is to design, build, and test three atmospheric and plasma physics experiments: a temperature measurement, a vector magnetic field probe, and a radio-sounding plasma-density measurement. We expect to obtain height profiles for the first two experiments and get a proof of concept for a novel plasma measurement.

3. Mission Overview: Radio Board • Measured variable: plasma density. • Processes: solar UV produces ionosphere >85 km. • Objectives: • Emit radio pulse which is reflected where index of refraction=0 • Measure density profile; identify E layer peak • For high-activity conditions: high-density patches descend to E-layer altitudes (“spread-F” effect)

4. Mission Overview: Main Board • Measured variable: temperature. • Processes: atmosphere heating/cooling mechanisms. • Objective: identify layers based on temperature profile • Measured variable: terrestrial magnetic field. • Processes: field controls charged-particle motion. • Objectives: • Measure vector B, dependence on latitude, geocentric distance. • For high S/N: detect low-frequency waves

5. Mission Research • Magnetic field: – Strongly involved in plasma structure and dynamics. – Experiment measures power-law decrease of field magnitude with geocentric distance. – differences in Earth's magnetic field can be caused by the interaction between charged particles from the Sun and the magnetosphere of a planet

6. WVU Functional Block Diagram Main Board Power Supply RBF G Flash Memory Reg uMag X/Y/Z DI G I T A L uController Geiger Counter A D C Thermistor Temperature Inertial Sensor Z Accel Ax/Ay/Az Gyro X/Y P/Q/R Legend Battery Mag X/Y/Z Power/Reg Comp/Store Sensors Power flow Comm/Con Data flow

7. uProcessor: Netburner MOD5213 Programming Language: C++ Programming Requirements: Periodic Interrupt Timers (PIT) 8 Analog to Digital Pins Serial Peripheral Interface (SPI) 5 Digital GPIO Pins Write 19 sensor channels to binary text file Write to external storage using a serial port additional serial port for uploading software

8. Main Board PCB Vertical Breakout Board

9. Geiger Counter Included a Geiger counter in payload to help verify Plasma Density experiment

10. WVU in RockSat 2010: Functional Block Diagram Radio Board Power Supply G RF in ANT Regs Fixed-f Pulse Tx ANT Pre-amp & Power filter RF out Super het LO Swept-f Pulse Tx ANT IF Amplifier uController A D C Flash Memory 10

11. Transmitter Schematic

12. Latest testing • Transmitter works on PCB when high-resonance frequency (>2 MHz) inductors are used. • If in addition, inductances are high, then we can use low capacitances.

13. Receiver Schematic

14. Programmable Circuit Elements • Programmable Capacitor used to control Transmitting and receiving frequencies • The Mod5213 PIT is used to control the digital capacitor (Max 1474) • We control simultaneously multiple capacitors: useful in extending range or resolution of effective capacitance

15. Final Payload

16. Concluding Remarks • Constructing our RockSat payload was a great hands on learning experience for experimental design and build. • WVU looks forward to participating in the next RockSat.