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WVU Rocketeers Preliminary Design Review. West Virginia University J. Yorick, B. Province, M. Gramlich Advisor: D . Vassiliadis November 2 2011. PDR Presentation Content. Section 1: Mission Overview Mission Overview Organizational Chart Theory and Concepts Concept of Operations
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WVU RocketeersPreliminary Design Review West Virginia University J. Yorick, B. Province, M. Gramlich Advisor: D. Vassiliadis November 2 2011
PDR Presentation Content • Section 1: Mission Overview • Mission Overview • Organizational Chart • Theory and Concepts • Concept of Operations • Expected Results • Section 2: System Overview • Subsystem Definitions • Critical Interfaces • System Level Block Diagram • System/Project Level Requirement Verification Plan • User Guide Compliance
PDR Presentation Contents • Section 3: Subsystem Design • Power Supply Subsystem (PSS) • PSS Block Diagram • PSS Key Trade Studies • PSS Risk Matrix/Mitigation • Flight Dynamics Subsystem (FDS) • FDS Block Diagram • FDS Key Trade Studies • FDS Risk Matrix/Mitigation
PDR Presentation Contents • Section 3: Subsystem Design (cont.) • Cosmic Ray Experiment Subsystem(CRE) • CRE Block Diagram • CRE Key Trade Studies • CRE Risk Matrix Mitigation • Radio Plasma Experiment Subsystem (RPE) • RPE Block Diagram • RPE Key Trade Studies • RPE Risk Matrix Mitigation
PDR Presentation Contents • Section 3: Subsystem Design (cont.) • Dusty Plasma Experiment Subsystem(DPE) • DPE Block Diagram • DPE Key Trade Studies • DPE Risk Matrix Mitigation • Greenhouse Gas Experiment Subsystem(GHGE) • GHGE Block Diagram • GHGE Key Trade Studies • GHGE Risk Matrix Mitigation
PDR Presentation Contents • Section 4: Prototyping Plan • Section 5: Project Management Plan • Schedule • Budget • Work Breakdown Structure
Mission Overview Ben Province
Mission Overview • Mission statement: develop a payload to measure properties of the space environment and conduct microgravity plasma experiments at approximately 110 km during RockSat flight. • Measurement of high-energy particles (CRE) • Radio-sounding of ionosphere plasma (RPE) • Creation and control of dusty plasma in microgravity environment(DPE) • Measurement of concentration of greenhouse gasses (GHGE) • Comparison to flight dynamics (FD) • Goal: determine physical conditions during flight and compare to standard models • Data analysis will complete the cycle of experiment design and implementation.
Theory and Concepts • High-energy particles: cosmic rays arrive from solar, galactic, and other sources. Variations with altitude and energy provide information about their sources. • Plasma: the distribution of low-energy charged particles changes continuously in the ionospheric E region. The radio sounding experiment will measure the plasma density and magnetic field as a function of altitude. We will compare the measurements against standard models. • Dusty Plasma: When dust is introduced to a plasma environment, the dust particles become negatively charged due to the plasma sheath effect. These negatively charged dust particles repel the positive ions in the plasma and form a lattice. The properties of this lattice vary with temperature and pressure.
Theory and Concepts Continued • Atmospheric Science: In meteorology, the rate at which the temperature of a volume of air would change with altitude is called a “lapse rate”The environmental lapse rate is the actual rate of temperature change with altitude observed in the atmosphere.An adiabatic lapse rate is the lapse rate calculated for an adiabatic differential volume of air. The adiabatic lapse rate varies with humidity and is a piecewise function for differential volumes that would include a H2O phase change within the interval over which the adiabatic lapse rate is being evaluated. (dry adiabatic lapse rate is a constant -9.8 °C per km)When the environmental lapse rate is less than the adiabatic lapse rate for the same location and conditions, the atmosphere is generally stable. When the environmental lapse rate is less than the adiabatic lapse rate for the same location and conditions, convection occurs. This often leads to a storm.
RockSat 2011: Concept of Operations h=117 km (T=02:53) Apogee h=75 km (T=01:18) RPE Tx ON DPE ON h=75 km (T=04:27) RPE Tx OFF DPE OFF h=52 km (T=00:36) End of Orion burn DPE begins h=10.5 km (T=05:30) Chute deploysRedundant atmo. valve closed h=0 km (T=13:00) Splashdown h=0 km (T=00:00) Launch; G-switch activationAll systems power up except RPE Tx and DPE
Expected Results: CRE • The number of particle collisions is expected to increase as the rocket moves higher into the atmosphere. This is expected due to the relatively closer proximity of the detector to the particle sources, which means there will be less atmospheric shielding between the sources and sensor. 2011 CRE Data Altitude (km) Count rates
Expected Results: DPE • A dusty plasma is a plasma which has much larger neutral particles suspended within the plasma. Under normal conditions, the electric forces are balanced by the weight of the dust particles, to form a well defined equilibrium lattice. This study seeks to see what variations in equilibrium and dynamic behaviors occur under microgravity conditions. It is suspected that these properties will be noticeably different under these varied conditions. • We would like to attain as many of the following milestones during the experiment as possible: • Ionization of gas to create a plasma • Suspension of dust within plasma environment • Optical confirmation of lattice structure • Controlled deformation and dynamic stimulations of lattice structure
Expected Results: GHGE • Assuming that the atmosphere is well-mixed, carbon dioxide and water-vapor should both be evenly distributed throughout the atmosphere. This (incorrect) assumption is used as a simplification in most basic greenhouse effect models. • Creating a local altitude profile of the CO2 concentration will provide insight into the reliability of models that assume CO2 is evenly distributed throughout the atmosphere. • Water-vapor is clearly not evenly distributed within the atmosphere as indicated by moisture-dependent weather systems and the water cycle. From this experiment, atmospheric lapse rates can be extrapolated and compared to calculated adiabatic lapse rates for the given conditions. The lapse rate profiles as well as their deviation from the dry adiabatic lapse rate should correspond to the weather systems and conditions observed near Wallops Flight Facility on the day of launch.
System Overview Justin Yorick
System Overview FD PSS CRE RPE DPE GHGE microprocessor Flash Memory
Design in Canister Other Experiments (not yet modeled) PSS FD subsystem Radio Tx(GHz) Radio Tx (MHz)
RockSat-C 2012 User’s Guide Compliance • Current team calculations place the mass of the payload at around 14lbs • At the current time, the CG is expected to lie within its required space. • High voltage components are used in the CRE experiment (500V capacitor), although this is a low power application. • Development of safety schematics are pending the finalization of the experiments. • Both the Special port, as well as the Atmospheric port will be used on this mission.
PSS: Functional Block Diagram Remainder of Payload Alkaline Batteries G-switch (1) Thyristor Circuit G-switch (2) G-switch (3) Legend Voltage Regulators Remove Before Flight Data Command/Control Power PSS
PSS: Risk Matrix • Risks for this subsystem are unlikely, but critical to the success of the mission. PSS.RSK.1: Single G switch fails/is connected incorrectly PSS.RSK.2: Some wire connections don’t survive launch PSS.RSK.3: RBF not removed correctly
FD: Functional Block Diagram FD Inertial Motion Sensor Magnetometer Z axis Breakout Board Power Board Netburner Flash Memory Thermistor Gyroscope Legend Data Commands/ Control Other Experiments Power
FD: Risk Matrix • This subsystem is still the “main” board since it contains the microprocessor and flash storage for all experiments. • Its functionality will ensure the success of many mission objectives. FD.RSK.1: Poor soldering of surface-mount devices (SMDs) soldering damaged during travel/prior to launch FD.RSK.2: Microcontroller fails in flight FD.RSK.3: If launch is delayed into midday, magnetometer calibration may be incorrect depending on temperature
CRE: Functional Block Diagram Geiger Tube (1) Geiger Tube (2) Geiger Tube (3) Geiger Tube (4) Legend Data/ Control Geiger Counter Power Flash Memory Micro Controller Power Board CRE
CRE: Risk Matrix • This subsystem will be largely unchanged from previous years and should be fairly reliable. CRE.RSK.1: Geiger tubes damaged/not properly secured
RPE: Functional Block Diagram Antennas Swept-f Rx Legend RPE Data/ Control Power Swept-f Pulse Tx Micro Controller Flash Memory PSS
RPE: Risk Matrix • This board has several points of failure with consequences for the experiment. • Results were inconclusive last year with internal antenna RPE.RSK.1: Wiring failure RPE.RSK.2: Plasma reflection not strong enough RPE.RSK.3: Tx and/or Rx sweep fails RPE.RSK.4: Tx-Rx sweep not synchronized RPE.RSK.5: Uncertainty in ionospheric conditions (ionospheric storm) RPE.RSK.6: Patch antenna not properly secured
Subsystem DesignDusty Plasma Experiment(DPE) Ben Province
DPE: Block Diagram Antenna Plasma Container Dusty Plasma Pressure and Temperature Sensors Optical Detection Laser Legend RF Signal Generator/ Amplifier Camera Data/ Control Power Micro Controller Optical Flash Memory PSS DPE
DPE: Risk Matrix • This experiment is new to our payload. • Due to the nature of the experiment, partial success is unlikely. • All risks are of high consequence DPE.RSK.1: Dust Injector fails DPE.RSK.2: Dust contacts container walls before forming lattice DPE.RSK.3: Leak causes pressure anomaly DPE.RSK.4: RF equipment damaged on launch
Subsystem DesignGreenhouse Gas Experiment(GHGE) Ben Province
GHGE: Functional Block Diagram Inlet Solenoids Experimental Volume Outlet Solenoids Static Atmospheric Outlet Solenoid Controller Pyroelectric CO2 Sensor H2O Vapor (Humidity) Sensor Pressure and Temperature Sensors Solenoid Controller Legend Micro Controller Dynamic Atmospheric Inlet Data/ Control TEC/Driver (for maintaining CO2 sensor temp) Flash Memory Power Airflow Thermistor PSS GHGE
GHGE: Trade Studies: CO2 Sensor • Note: The SOHA Tech SH-300-DTH is a dual sensor that measures both CO2 and relative humidity.
GHGE: Trade Studies: Humidity Sensor • The Honeywell HCH-1000-002 is clearly a good addition to the payload even if the SH-300-DTH dual sensor is also used. The low price of this sensor ($5.39) makes this decision easy to justify.
GHGE: Risk Matrix • This experiment is ambitious given the available technology and volume and mass restrictions • Partial success is feasible if the microcontroller is programmed to continue parts of the experiment when failure criteria is met for others. • IE: Thermal equilibrium cannot be reached, so solenoids are opened so that pressure, temperature, and humidity readings are continued. GHGE.RSK.1: A suitable pyroelectric CO2 sensor cannot be obtained GHGE.RSK.2: The pyroelectric sensor cannot be maintained at a stable temperature GHGE.RSK.3: Solenoids fail GHGE.RSK.4: Thermal equilibrium time severely limits data acquisition rate
Prototyping Plan Justin Yorick
Prototyping Plan Risk/Concern Action Improper mounting or soldering could cause total system failure Prototype PSS and ensure connections are mechanically and electrically sound PSS Vibrations Vibration testing with industrial partner ATK to ensure proper design FD Damage to Geiger tube array could compromise experiment Use previously successful heritage design for container CRE Timing or signal between Tx and receiver not calibrated. Ground testing can verify timing calibration of subsystem RPE
Prototyping Plan RF generators must be properly designed to overcome vibrations and spin of rocket, to ensure dynamic stability of lattice Explore options with Physics Dept. to develop a suitable control process DPE Build prototype and test readings on ground. Consider addition of small impellor if needed. Use of static ports do not provide sufficient samples for GHG sensors GHGE
Project Management Plan Ben Province
Organizational Chart Project Manager Justin Yorick System Engineer Marc Gramlich Faculty Advisor Dimitris Vassiliadis Mark Koepke Yu Gu Safety Engineer Phil Tucker CFO Dimitris Vassiliadis Sponsors WVSGC, Dept. of Physics, Testing Partners ATK Aerospace WVU CEMR Structural Design Ben Province Legacy Components B. Province GHGE B. Province RPE Mike Spencer DPE J. Yorick Simulation and Testing J. Yorick B. Tepke
Schedule • 11/7 Component selection should be complete, all electronic components ordered • 11/25 Circuit schematics complete, PCBs ordered • 11/30 CDR due (mass and power budgets virtually complete, placement of all components demonstrated in CAD) • 2/13 ISTR due (subsystem prototypes should be fully functional, microprocessor programming drafted) • 2/22 Detailed comparison between CAD and payload; testing • 3/21 All subsystems fully assembled (most should be mounted on plates) • 4/2 PSITR due (payload should be virtually complete, microprocessor programming well drafted) • 4/23 FFMSTR due • 5/28 LRR due (payload fully complete, microprocessor programming finalized) • 6/15 Integration at WFF • 6/21 Launch
Budget • Approximate budget: • PSS: $100 • FD incl. magnetometers: $1100 • RPE: $600 • CLE: $500 • GHGE: $600 • DPE: $800 • Other: $500 • Total: $4200 • If budget exceeds means, legacy components can be salvaged from previous payloads. • Lead times: of the order of <1 week to 4 weeks.
Work Breakdown Schedule • The subsystems are prioritized from left to right. The level of priority drops from left to right. The priority of events for each subsystem drops from top to bottom of each block. GHGE DPE RPE PSS FD • Design Plasma Container and optical detection system • Design RF signal generator • Work towards previously listed dusty plasma milestones • Finalize physical location and shielding to prevent interference with RPE • Finalize sensor selection and order sensors • CAD design mechanical systems to interface with atmospheric port • Finalize sweep frequencies • Complete patch antenna and Langmuir Probe design • Review/update voltage regulator circuits to ensure that this year’s power requirements are met • Determine alkaline cell quantity configuration • Reprogram Netburner in order to integrate new systems