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. WolfeFaculty advisors: Y. Gu, D.J. Pisano, D. Vassiliadis

June 2010

– 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.

Mission Statement

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)

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

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

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WVU Functional Block Diagram

Main Board

Power flow

Comm/Con

Data flow

Legend

Power/Reg

Comp/Store

Sensors

Power Supply

Thermistor

uMag X/Y/Z

G

uController

FlashMemory

RBF

Z Accel

Gyro X/Y

ADCInertial

Sensor

Reg

DIGITAL

GeigerCounter

Mag X/Y/Z

P/Q/R

Ax/Ay/Az

Temperature

Battery

uProcessor: Netburner MOD5213

Programming Language: C++

Programming Requirements: Periodic Interrupt Timers (PIT)8 Analog to Digital PinsSerial Peripheral Interface (SPI)5 Digital GPIO PinsWrite 19 sensor channels to binary text fileWrite to external storage using a serial portadditional serial port for uploading software

Main Board PCB Vertical Breakout Board

Geiger Counter

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

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WVU in RockSat 2010: Functional Block Diagram

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Power Supply

Swept-fPulse Tx

Radio Board

Fixed-fPulse TxPre-amp &

Power filter

SuperhetLO

Amplifier

IF

G

RegsANT

RF in

uControllerADC

FlashMemory

ANT

ANT

RF out

Transmitter Schematic

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.

Receiver Schematic

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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

Capacitance (pF)

0

2

4

6

8

10

12

14

0 5 10 15 20 25 30 35

Number of Pulses

Capacitance (pF)

Final Payload

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.