WVU Returns to RockSat 2010: A Research and Education
Project
WVU Returns to RockSat 2010: A Research and Education
ProjectWest 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
11The 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 StatementMission Overview: Radio
BoardMeasured variable: plasma density. Processes: solar UV
produces ionosphere >85 km.Objectives:Emit radio pulse which is
reflected where index of refraction=0Measure density profile;
identify E layer peakFor high-activity conditions: high-density
patches descend to E-layer altitudes (spread-F effect)
Mission Overview: Main BoardMeasured 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
4Mission ResearchMagnetic 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
6WVU Functional Block DiagramMain BoardPower flow
Comm/Con
Data flowLegendPower/Reg
Comp/Store
SensorsPower SupplyThermistoruMag X/Y/ZG
uControllerFlashMemoryRBFZ AccelGyro
X/YADCInertialSensorRegDIGITALGeigerCounterMag
X/Y/ZP/Q/RAx/Ay/AzTemperatureBatteryuProcessor: 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 BoardGeiger Counter
Included a Geiger counter in payload to help verify Plasma
Density experiment WVU in RockSat 2010: Functional Block
Diagram1010Power SupplySwept-fPulse TxRadio BoardFixed-fPulse
TxPre-amp &Power filterSuperhetLOAmplifierIFG RegsANTRF
inuControllerADCFlashMemoryANTANTRF out10Solenoid valveTransmitter
SchematicLatest testingTransmitter 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 Schematic14Programmable 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
Final Payload
Concluding RemarksConstructing our RockSat payload was a great
hands on learning experience for experimental design and build.WVU
looks forward to participating in the next RockSat.
11
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D DTitle
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WVU RockSat 2010: Transmitter
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Size Document Number Rev
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v. 2
WVU RockSat 2010: Transmitter
Custom
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Title
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v. 2
WVU RockSat 2010: Transmitter
Custom
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Primary of radiooscillator coil
Gnd
RADIO BOARD: Transmitter
V
V
470470
MAX1474
33p
MAX1474
33p
1000p1000pANTENNAANTENNA
10u10u
360u360u
1
2
10n10n10u10u
1m1m
1 2
1000p1000p
10M
R_Free_Space
10M
R_Free_Space
10k10k
FREQ = 1e4VAMPL = 1VOFF = 0
FREQ = 1e4VAMPL = 1VOFF = 0
47u47u
2N44012N4401
5.1k5.1k
99
9797
11
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E ETitle
Size Document Number Rev
Date: Sheet of
WVU RockSat 2010: Receiver
A
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Title
Size Document Number Rev
Date: Sheet of
WVU RockSat 2010: Receiver
A
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Title
Size Document Number Rev
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WVU RockSat 2010: Receiver
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RADIO BOARD: Receiver
Active Filter
Detector
To detector
To uProcessor
+
-
OUT
+
-
OUT
Ra
1k
Ra
1k
RG
1k
RG
1k
+
-
OUT
5050
10p10p
OP-27OP-27+
-
OUT
1n1n
0.10.1
1k1k
0.10.13.6k3.6k
D1N914D1N914 470470
270k270k
0.10.1
1k1k
AntennaAntenna
10k10k
10k10k
1k1k
Chart12.12.52.93.33.744.44.85.15.45.86.26.56.87.27.57.88.18.58.89.19.49.710.110.410.71111.311.611.912.212.5
Capacitance (pF)Number of PulsesCapacitance (pF)
Sheet1Number of PulsesCapacitance
(pF)02.112.522.933.343.75464.474.885.195.4105.8116.2126.5136.8147.2157.5167.8178.1188.5198.8209.1219.4229.72310.12410.42510.726112711.32811.62911.93012.23112.5
Sheet1
Capacitance (pF)Number of PulsesCapacitance (pF)