RockSat-C 2011ISTR

Individual Subsystem Testing Report

WVU RocketeersWest Virginia University

2/14/2012

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Team MembersJustin YorickBen ProvenceMike SpencerStudent AdvisorMarc GramlichFaculty advisorDimitris Vassiliadis

RockSat-C 2011ISTR

Mission Overview

• The mission seeks to measure several variables of the upper atmospheric environment and record the dynamics of a contained plasma in a microgravity setting.

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RockSat-C 2011ISTR

Functional Block Diagrams

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PSS

DPE

RPE

GHGE

FD

CRE

Power

Data

RockSat-C 2011ISTR

FBD: Cosmic Ray Experiment

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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 2011ISTR

FBD: Flight Dynamics Board

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Power

Data

Legend

Commands/ Control

Other Experiments

RockSat-C 2011ISTR

FBD: Greenhouse Gas Experiment

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Power

Data/Control

High Pressure Manifold

Solenoid Controlled

Airflow

Static Atmospheric

Outlet

Low Pressure Manifold

Pressure and Temperature

Sensors

H2O Vapor (Humidity)

Sensors

NDIR CO2 Sensor

PSS

Micro Controller

Flash Memory

Unvalved Airflow

Pneumatic Cylinder

Experimental Volume Optical Encoder

Linear Actuator and Solenoid Controllers

RockSat-C 2011ISTR

FBD: Plasma Experiment

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PSS 555 Circuit Primary Step up transformer

DIAC switch

Secondary Step up transformers

Specimen Control Volume

Camera

FD

Power

Data

RockSat-C 2011ISTR

Changes from CDR

• The design of the DPE has been modified. The experiment now seeks to measure plasma convection under microgravity conditions.

• The other subsystems remain largely unchanged from the CDR.

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RockSat-C 2011ISTR

Program Management and Team Updates

• Mike Spencer has joined the team.• The team organizational structure

remains largely unchanged since last semester.

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RockSat-C 2011ISTR

Schedule Update

• As of this point, the CRE and FD are have corrected design and are in the component ordering phase.

• The GHGE has been modeled and simulated . The required parts have arrived and construction will begin pending machining of the brackets.

• With the addition of Mike Spencer to the team, and resolution of conflicts with WFF, parts are ready to be ordered for this system.

• The DPE will be constructed from an off the shelf plasma globe. Construction will begin once a product of proper size and power output is chosen (~ 1 week)

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RockSat-C 2011ISTR

Subsystem Overview

• Flight Dynamics Subsystem: Marc Gramlich

• Cosmic Ray Experiment: Marc Gramlich • Greenhouse Gas Experiment: Ben

Provence• Dusty Plasma Experiment: Justin Yorick• Radio Plasma Experiment: Justin Yorick

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RockSat-C 2011ISTR

Dusty Plasma Subsystem Update

• Status– The DPE will use an off the shelf system

to generate the plasma streamers in this experiment.

– Designs and fabrication techniques for a custom made glass control volume have been discussed with technicians in the WVU Chemistry Department.

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RockSat-C 2011ISTR

Radio Plasma Experiment Update

• As discussed in previous communications, the RPE design has been finalized and cleared with WFF.

• Ground testing will be limited to measurement of transmission output since we cannot reproduce the ionospheric plasma in the lab

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RockSat-C 2011ISTR

Flight Dynamics Subsystem Update• Status

– The PCB’s for this subsystem have been fully revised and are ready for ordering– PCBs below, schematics on next few slides

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RockSat-C 2011ISTR

Flight Dynamics Sensor Circuits Schematic

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RockSat-C 2011ISTR

Power Circuits Schematic

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RockSat-C 2011ISTR

Greenhouse Gas Subsystem Update• Status

– Mechanical elements have been modeled further in Creo Elements•Pneumatic plumbing has been designed using manufacturer CAD files of actual components to ensure proper fit•Simulation confirms design choices for components that will be produced by the WVU Physics dept. machine shop.

– Control system development is underway•Software FBD complete•Microcontroller programming cannot be completed until physical prototype is constructed

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RockSat-C 2011ISTR

Greenhouse Gas Subsystem Update

• All critical hardware has been tested (static analysis) to ensure that deformations are within an acceptable range and that maximum stresses do not exceed material yield strength.– Analyses of the two most critical of

these components, the lower main bracket, and the CV door are highlighted on the next two slides

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RockSat-C 2011ISTR

Greenhouse Gas Subsystem Update

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RockSat-C 2011ISTR

Greenhouse Gas Subsystem Update

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RockSat-C 2011ISTR

Greenhouse Gas Subsystem Update

• Deformations in areas of concern were small: on the order of 10^-5 inches

• Maximum stress predicted is 5.18 KSI, while the yield strength of 6061-T6, the alloy chosen for the custom parts is about 35 KSI

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RockSat-C 2011ISTR

Greenhouse Gas Subsystem Update

• Although brackets are presently still in the machine shop, we have test-fitted some components of the linear actuator.

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RockSat-C 2011ISTR

Greenhouse Gas Subsystem Update

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• Subsystem expected to be completed around the first week of May.

RockSat-C 2011ISTR

Lessons Learned

• Subsystem testing is a verification of design. Since the team spent extra time on simulation and calculation of key parameters, it seems less time will have to be spent on making corrections later on.

• At this point, it seems like making critical design choices earlier could have led to faster completion times, but not necessarily better results.

• Extensive simulation enables the team to be more confident in the final design, minimizing valuable time spent on design revisions closer to launch the date.

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RockSat-C 2011ISTR

Conclusions

• At this point, construction of the subsystem mechanical components needs to be finalized.

• After completion of mechanical elements, software components can be tested to ensure proper individual system operation.

• Pending successful completion of this stage, the payload will be ready for total system testing.

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