RockSat-C 2012PDR

WVU RocketeersPreliminary Design Review

West Virginia UniversityJ. Yorick, B. Province, M. Gramlich

Advisor: D. VassiliadisNovember 2 2011

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RockSat-C 2012PDR

PDR Presentation Content

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• 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

RockSat-C 2012PDR

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

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RockSat-C 2012PDR

• 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

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PDR Presentation Contents

RockSat-C 2012PDR

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

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RockSat-C 2012PDR

PDR Presentation Contents

• Section 4: Prototyping Plan• Section 5: Project Management Plan

– Schedule– Budget– Work Breakdown Structure

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RockSat-C 2012PDR

Mission OverviewBen Province

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RockSat-C 2012PDR

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.

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RockSat-C 2012PDR

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.

•

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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.

RockSat-C 2012PDR

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. 10

RockSat-C 2012PDR

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RockSat 2011: Concept of Operations

h=0 km (T=00:00)Launch; G-switch activation

All systems power up except RPE Tx and DPE

h=75 km (T=01:18) RPE Tx ON

DPE ON

h=75 km (T=04:27)RPE Tx OFFDPE OFF

h=117 km (T=02:53)Apogee

h=0 km (T=13:00)Splashdown

h=10.5 km (T=05:30)Chute deploysRedundant atmo. valve closed

h=52 km (T=00:36)End of Orion burn

DPE begins

RockSat-C 2012PDR

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.

12Count rates

Alti

tude

(km

)

2011 CRE Data

RockSat-C 2012PDR

Expected Results: RPE

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•  

0 20 40 60 80 100 120 140 1600.00E+00

5.00E+05

1.00E+06

1.50E+06

2.00E+06

2.50E+06

3.00E+06

3.50E+06

4.00E+06

4.50E+06

E Region Plasma Frequency Variability

f_ce (Hz)f_pe (Hz)f_uh (Hz)

Altitude (km)

Freq

uenc

y (H

z)

RockSat-C 2012PDR

Expected Results: DPE

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• 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

RockSat-C 2012PDR

Expected Results: GHGE

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• 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.

RockSat-C 2012PDR

System OverviewJustin Yorick

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RockSat-C 2012PDR

System Overview

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PSS

microprocessorFlash

Memory

FD

CRE

RPE

GHGE

DPE

RockSat-C 2012PDR

Design in Canister

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FD subsystem

PSS

Radio Tx(GHz)

Radio Tx (MHz)

Other Experiments (not yet modeled)

RockSat-C 2012PDR

Critical Interfaces

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Interface Name Brief Description Potential Solution

PSS<->allThe PSS is a universal power supply to the payload. The experiments as well as the CPU are dependent on this structure. This structure’s survival and proper operation is paramount for mission success.

The PSS will be a custom PCB to minimize stray wires and mass. The batteries will be placed below the board to maximize space usage efficiency.

FD<->StructureThe FD board contains multiple dynamic sensors that will be used to compare the flight’s dynamics to WFF telemetry. It is key that this board is attached to the payload in such a way to avoid stray vibration or resonance phenomena.

Secure connections are the primary tool to combat unwanted vibration. Prototyping and subsystem testing will reveal if further measures are needed.

RPE<->Special port

The RPE must have a secure and reliable connection to the special port

Further research and design will allow the team to chose the most reliable connection methods to secure mission success

DPE<->Structure

The DPE experiment will require use of a sealed, low pressure vessel to test the dusty plasma. The experiment will be imaged by a laser and imaging device. Stray vibrations from improper mounting could destroy image quality, and thus this experiment.

Properly designed connections and components should minimize the risk of destructive vibrations. Further research will provide insight into additional potential solutions.

GHGE<->Atmospheric port

.The GHGE requires a reliable connection to the atmospheric port. Design should ensure that a sufficient atmospheric sample can be given to the GHG sensors. It is also critical that the safety valves will operate correctly during the splashdown event.

Proper calculation of major and minor losses in the tubing should ensure that the sensors will see their proper sample quantities. Proper testing will ensure the safety valves will not allow water into the system.

RockSat-C 2012PDR

Requirement Verification

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Requirement Verification Method DescriptionThe PSS fully activates and stays on during launch.

Demonstration Triggering the g-switches will allow the group to test the power out put to various system components using a DMM

The RPE activates at the appropriate prescribed time, and deactivates at its assigned time

Demonstration During the PSS testing, the team will inspect the RPE and test to see if it activates at the proper times.

The DPE is able to survive the vibrations during the rocket flight.

Testing Vibration testing with partner ATK as well as spin testing with WVU CEMR

The entire system meets the mass, CG, and electrical requirements as prescribed by RockSat-C guidelines

Inspection Physical test will ensure RockSat-C compliance

RockSat-C 2012PDR

RockSat-C 2012 User’s Guide Compliance

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• 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.

RockSat-C 2012PDR

Subsystem Design

Power Supply Subsystem(PSS)Ben Province

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RockSat-C 2012PDR

PSS: Functional Block Diagram

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Power

Data

Legend

Voltage Regulators

Remove Before Flight

Alkaline Batteries

Remainder of Payload

PSS

G-switch (1)

G-switch (2)

G-switch (3)Thyristor Circuit

Command/Control

RockSat-C 2012PDR

PSS: Risk Matrix

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Consequence

PSS.RSK.3

PSS.RSK.2

PSS.RSK.1

Possibility

PSS.RSK.1: Single G switch fails/is connected incorrectlyPSS.RSK.2: Some wire connections don’t survive launchPSS.RSK.3: RBF not removed correctly

• Risks for this subsystem are unlikely, but critical to the success of the mission.

RockSat-C 2012PDR

Subsystem Design

Flight Dynamics (FD)Ben Province

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RockSat-C 2012PDR

FD: Functional Block Diagram

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Power

Data

Legend

FD

PowerBoard

MagnetometerInertial Motion Sensor

Thermistor

Z axis Breakout Board

Flash Memory

Gyroscope

Netburner

Commands/ Control

Other Experiments

RockSat-C 2012PDR

FD: Risk Matrix

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Consequence

FD.RSK.2

FD.RSK.3

FD.RSK.1

Possibility

FD.RSK.1: Poor soldering of surface-mount devices (SMDs) soldering damaged during travel/prior to launchFD.RSK.2: Microcontroller fails in flightFD.RSK.3: If launch is delayed into midday, magnetometer calibration may be incorrect depending on temperature

• 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.

RockSat-C 2012PDR

Subsystem Design

Cosmic Ray Experiment (CRE)Ben Province

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RockSat-C 2012PDR

CRE: Functional Block Diagram

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Power

Data/Control

Legend

Flash Memory

Geiger Counter

Power Board Micro Controller

CRE

Geiger Tube (1)

Geiger Tube (3)

Geiger Tube (2)

Geiger Tube (4)

RockSat-C 2012PDR

CRE: Risk Matrix

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CRE.RSK.1

Possibility

CRE.RSK.1: Geiger tubes damaged/not properly secured

• This subsystem will be largely unchanged from previous years and should be fairly reliable.

RockSat-C 2012PDR

Subsystem Design

Radio Plasma Experiment (RPE)Ben Province

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RockSat-C 2012PDR

RPE: Functional Block Diagram

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Power

Data/ Control

Legend

RPE

Swept-fPulse Tx Micro Controller

PSS

Flash Memory

Antennas Swept-f Rx

RockSat-C 2012PDR

RPE: Risk Matrix

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Consequence

RPE.RSK.6 RPE.RSK.1

RPE.RSK.4 RPE.RSK.3 RPE.RSK.2

RPE.RSK.5

Possibility

RPE.RSK.1: Wiring failureRPE.RSK.2: Plasma reflection not strong enoughRPE.RSK.3: Tx and/or Rx sweep failsRPE.RSK.4: Tx-Rx sweep not synchronizedRPE.RSK.5: Uncertainty in ionospheric conditions (ionospheric storm)RPE.RSK.6: Patch antenna not properly secured

• This board has several points of failure with consequences for the experiment.

• Results were inconclusive last year with internal antenna

RockSat-C 2012PDR

Subsystem DesignDusty Plasma Experiment

(DPE)Ben Province

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RockSat-C 2012PDR

DPE

RF Signal Generator/Amplifier

Micro Controller

PSS

Flash Memory

DPE: Block Diagram

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Power

Data/Control

Legend

Antenna Plasma Container

Camera

Optical Detection Laser

Optical

Pressure and Temperature

Sensors

Dusty Plasma

RockSat-C 2012PDR

DPE: Trade Studies Camera

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Camera DVR523V HERO M3185A

Cost 6 4 8Size and Mass 7 6 10

Resolution (video) 2 8 2Convenience of Interface 10 9 1

Power Requirements 6 5 10Average: 6.2 6.4 6.2

RockSat-C 2012PDR

DPE: Risk Matrix

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Consequence

DPE.RSK.1DPE.RSK.4 DPE.RSK.2 DPE.RSK.3

Possibility

DPE.RSK.1: Dust Injector failsDPE.RSK.2: Dust contacts container walls before forming latticeDPE.RSK.3: Leak causes pressure anomalyDPE.RSK.4: RF equipment damaged on launch

• This experiment is new to our payload.

• Due to the nature of the experiment, partial success is unlikely.

• All risks are of high consequence

RockSat-C 2012PDR

Subsystem DesignGreenhouse Gas Experiment

(GHGE)Ben Province

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RockSat-C 2012PDR

GHGE: Functional Block Diagram

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Power

Data/Control

Legend

GHGE

Dynamic Atmospheric

Inlet

Inlet Solenoids

Airflow

Static Atmospheric

Outlet

Outlet Solenoids

Experimental Volume

Pyroelectric CO2 Sensor

H2O Vapor (Humidity)

Sensor

Pressure and Temperature

Sensors

PSS

Micro Controller

Flash Memory

SolenoidController

SolenoidController

TEC/Driver (for maintaining CO2

sensor temp)

Thermistor

RockSat-C 2012PDR

GHGE: Trade Studies: CO2 Sensor

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• Note: The SOHA Tech SH-300-DTH is a dual sensor that measures both CO2 and relative humidity.

CO2 Sensor Apollo IRC-A1

Dynament TDS0057

SOHA TechSH-300-DTH

Cost 3 5 8Accuracy 1 6 9

Warm Up Time 1 6 4Signal Conditioning 3 10 10

Power Requirements 2 6 6Repeatability 2 8 8

Average: 2.0 6.8 7.5

RockSat-C 2012PDR

GHGE: Trade Studies: Humidity Sensor

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• 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.

H20 Sensor HoneywellHCH-1000-002

MEASHM1500LF

SOHA TechSH-300-DTH

Cost 9 1 10 (free if used for CO2)

Accuracy 9 6 3Response Time 4 6 1

Signal Conditioning 3 8 10Power Requirements 9 9 9

Operating Temp 10 6 N/AAverage: 7.3 6.0 6.6

RockSat-C 2012PDR

GHGE: Risk Matrix

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Consequence

GHGE.RSK.3

GHGE.RSK.2 GHGE.RSK.1

GHGE.RSK.4

Possibility

GHGE.RSK.1: A suitable pyroelectric CO2 sensor cannot be obtainedGHGE.RSK.2: The pyroelectric sensor cannot be maintained at a stable temperatureGHGE.RSK.3: Solenoids failGHGE.RSK.4: Thermal equilibrium time severely limits data acquisition rate

• 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.

RockSat-C 2012PDR

Prototyping PlanJustin Yorick

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RockSat-C 2012PDR

Prototyping Plan

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Improper mounting or soldering could cause total

system failurePSS

FD

CRE

RPE

Vibrations

Damage to Geiger tube array could compromise experiment

Timing or signal between Tx and receiver not

calibrated.

Prototype PSS and ensure connections are

mechanically and electrically sound

Vibration testing with industrial partner ATK to

ensure proper design

Use previously successful heritage design for container

Ground testing can verify timing calibration

of subsystem

Risk/Concern Action

RockSat-C 2012PDR

Prototyping Plan

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RF generators must be properly designed to

overcome vibrations and spin of rocket, to ensure

dynamic stability of lattice

DPE

Explore options with Physics Dept. to

develop a suitable control process

GHGEUse of static ports do not provide sufficient samples

for GHG sensors

Build prototype and test readings on ground. Consider addition of small

impellor if needed.

RockSat-C 2012PDR

Project Management PlanBen Province

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RockSat-C 2012PDR

Organizational Chart

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Project ManagerJustin Yorick

System EngineerMarc Gramlich

Faculty AdvisorDimitris Vassiliadis

Mark KoepkeYu Gu

SponsorsWVSGC,

Dept. of Physics,

Testing PartnersATK Aerospace

WVU CEMR

Safety EngineerPhil Tucker

Legacy ComponentsB. Province

GHGEB. Province

RPEMike Spencer

DPEJ. Yorick

Structural DesignBen Province

CFODimitris Vassiliadis

Simulation and TestingJ. YorickB. Tepke

RockSat-C 2012PDR

Schedule

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• 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

RockSat-C 2012PDR

Budget

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• 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.

 

RockSat-C 2012PDR

Work Breakdown Schedule

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• 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.

FDRPEDPEGHGE PSS

• Reprogram Netburner in order to integrate new systems

• Finalize sweep frequencies

• Complete patch antenna and Langmuir Probe design

• 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

• Review/update voltage regulator circuits to ensure that this year’s power requirements are met

• Determine alkaline cell quantity configuration

• Finalize sensor selection and order sensors

• CAD design mechanical systems to interface with atmospheric port

RockSat-C 2012PDR

• Action Items– Work on selection of all electronic components– Design DPE and GHGE circuitry– Build, simulate, or analyze all electronic subsystems to

determine precise power requirements (dependant on item above)

– Complete detailed mass budget including batteries (dependant on item above)

– Use computer modeling to design patch antenna and Langmuir probe to withstand dynamic pressure and thermal requirements

– Revise mechanical design of new subsystems and integrate them into a full-canister structural CAD drawing

Conclusion

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