RockSat-C 2012PDR

Harding Flying Bison RockSat-C 2012 Rocket Team

Preliminary Design Review

Harding UniversityBonnie Enix, Joshua Griffith, Will Waldron, Edmond Wilson,

David Stair

22 October 2011

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RockSat-C 2012PDR

Mission Overview

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RockSat-C 2012PDR

Mission Overview – Mission Statement

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Design, build, test and fly a spectrometer that will measure transmission spectra of gases in Earth’s atmosphere at lower altitudes and the Sun’s irradiance at higher altitudes

Tabulate and interpret spectra and create a technical report summarizing the results obtained and conclusions reached

RockSat-C 2012PDR

Mission Overview – Concepts

Percent of atmosphere below rocket as a function of time

RockSat-C 2012PDR

Mission Overview – Concepts

With the spectrometer located inside the Earth’s atmosphere, the Sun’s light can be used as the optical light source in obtaining transmission spectra of Earth’s atmosphere

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SunAtmospheric GasesSpectrometerComputer withData Storage

I0I

RockSat-C 2012PDR

Mission Overview – Concepts

Once above Earth’s atmosphere, the spectrum of the Sun’s surface can be measured without interference.

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SunSpectrometerComputer withData Storage

I0

RockSat-C 2012PDR

Mission Overview – Concepts

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Spectrum of Earth’s atmosphere at 297 ft. measured with flight spectrometer.Water and oxygen peaks are clearly visible.

oxygen

water

RockSat-C 2012PDR

Mission Overview – Theory

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Intensity of radiation of frequency,

Intensity of radiation incident on the sample

, afterpassing through the sampleAbsorption Cross Section at frequency,

NL

Transmittance of light through a sample obeys

the Beer-Lambert Law

Sample path length

Number of absorbing molecules per volume

SampleI (ν)

I0(ν)

I (ν)

I0(ν)

RockSat-C 2012PDR

Mission Overview – Timeline

t ≈ 1.3 min

Altitude: 75 km

Event A Occurs

t ≈ 15 min

Splash Down

t ≈ 1.7 min

Altitude: 95 km

Event B Occurs

-G switch triggered

-All systems on

-Begin data collection

t = 0 min

t ≈ 4.0 min

Altitude: 95 km

Event C OccursApogee

t ≈ 2.8 min

Altitude: ≈115 km

End of Orion Burn

t ≈ 0.6 min

Altitude: 52 km

t ≈ 4.5 min

Altitude: 75 km

Event D Occurs

Altitude

t ≈ 5.5 min

Chute Deploys

When G-switch activates payload, spectra will be measured at a frequency of 0.5 Hz for 6 minutes producing 720 spectra

RockSat-C 2012PDR

Mission Overview – Expected Results

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G-Switch will function properly to turn on electronics

Batteries will be sufficient to power the payload for 20 minutes

Instrument will perform well and 100 useable spectra will be recorded, 50 in the atmosphere and 50 above the atmosphere

Concentrations of water vapor and oxygen will be measured as a function of altitude

Ozone will be measured at higher altitudes

Other pollutant gases may be detected

RockSat-C 2012PDR

Mission Overview – Mission Significance

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This mission will advance technology, collect science data and develop operations capabilities by:

Integration of science instruments with mobile platforms

Advance autonomous exploration and data retrieval using self-contained mobile science systems

RockSat-C 2012PDR

Overview – Benefits from Mission Success

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We are designing a suite of instruments to be deployed on the surface of Mars to measure the presence of biogases that might indicate life on that planet.

The high altitude spectra obtained by our RockSat-C instrument will be similar in some ways to those expected on Mars in terms of gas density, pressure and temperature.

The robustness and space mission readiness of our instruments will be verified by their excellent condition after going through the launch process at NASA Wallops Flight Facility including the rigorous pre-flight tests, launch and recovery.

RockSat-C 2012PDR

System Overview

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RockSat-C 2012PDR

System Overview – Description of Payload

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The Harding University RockSat-C 2012 science payload consists of aspectrometer for repeatedly measuring the spectrum of the atmosphererecorded through the optical port of a NASA sounding rocket launchedfrom Wallops Flight Facility eastward over the Atlantic. The apogee of therocket trajectory is at an altitude of 115 km.

There is an additional sensor that measures the total Solar irradiance asa function of altitude.

An attitude and direction sensor is used to attempt to record the directionat which the spectrometer is pointed for each spectrum measured

RockSat-C 2012PDR

System Overview – Subsystem Definitions

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Power Distribution – Power will be from a bank of five 9 volt batteries

G-Switch – TBD

Spectrometer – StellarNet EPP 2000 UVN-SR

Total Irradiance Sensor – OSI Optoelectronics UDT-455UV

Attitude and Direction Sensor -- YEI 3-Space Sensor

Microprocessor – TERN Model EL Microprocessor with CF Memory

RockSat-C 2012PDR

System Overview – Spectrometer

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Internal view of StellarNet EPP 2000 UVN-SR showing light path

RockSat-C 2012PDR

Mission Overview – Spectrometer

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Spectrometer mounted on canister plate. Fixture to hold spectrometer lens and total irradiance sensor shown attached at front of plate, just left of center.

RockSat-C 2012PDR

System Overview – Location of Components

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Location of the two mounting plates, spectrometer, light collecting lenses ofspectrometer and total irradiance sensor.

RockSat-C 2012PDR

System Overview – Functional Block Diagram

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LensUV/VIS Spectrometer

Signal Conditioner for

CCD Array

Embedded Controller with 2 GB Memory

PDSignal

Conditioner for Photodiode

G-SwitchPower

Distribution System

Battery Power Supply RBF

Fiber OpticCable

Black lines – powerBlue lines -- signal

RockSat-C 2012PDR

System Overview – Power Distribution

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Embedded Controller

G-SwitchPower

Distribution System

Battery Power Supply RBF

Signal Conditioner for

CCD Array

UV/VIS Spectrometer

Signal Conditioner for

Photodiode

Functional block diagram of power distribution system.

RockSat-C 2012PDR

System Overview – Spectrum Capture

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Embedded Controller with 2 GB Flash Memory

Fiber OpticCable

ADC 0 CLK 1 CLK 2

φCLK φROG

Vout

VGG

UV/VIS Spectrometer

Signal Conditioner for CCD Array

Vsignal inVsignal out

Functional block diagram of spectrometer interfaced to embedded controller.

RockSat-C 2012PDR

System Overview – Spectrum Capture

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Two clock signals are required for the CCD array to read out data at Vout

фROG

фCLK

Vout

RockSat-C 2012PDR

System Overview – Irradiance Measure

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Embedded Controller with 2 GB Memory

PDSignal

Conditioner for Photodiode

A photodiode, sensitive to ultraviolet and visible light, is used to measure thetotal irradiance of the Sun as a function of altitude.

RockSat-C 2012PDR

System Overview – User Guide Compliance

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Requirement Payload Requirement StatusMass allotment: your allotment TBDVolume allotment: your allotment TBDThe payload’s center of gravity (CG):

In 1”X1”X1” envelope of centroid (or in area designated

for sharing teams?

TBD

Activation met under requirement: (either 1.SYS.1 or 1.SYS.2)

1.SYS.2 Not Yet

Structure mounts: Top and bottom bulkheads. No mounts to sides of cans.

Yes

Sharing: Fully developed? No

RockSat-C 2012PDR

System Overview – Critical Interfaces

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Interface Name Brief Description Potential Solution

Power Distribution Board (PDB)

The electrical power system boards will need to mount to the RockSat-C deck to fix them rigidly to the payload canister. The connection should be sufficient to survive 20Gs in the thrust axis and 10 Gs in the lateral axes. Buckling is a key failure mode.

Heritage shows that stainless steel or aluminum stand-offs work well. Sizes and numbers required will be determined by CDR.

Spectrometer (UVN-SR)The spectrometer must be fixed rigidly to the main canister chassis plate. The connection should be sufficient to survive 20Gs in the thrust axis and 10 Gs in the lateral axes.

Use of four 10-32 Screws should be enough to achieve the desired robustness

Embedded Controller (TERN-EL)

The TERN Model EL Embedded Controller must be rigidly connected to our RockSat-c secondary chassis plate. The controller has pre-drilled clearance holes for 4-40 screws. The circuit board is made so that these holes are grounded

Secure plastic standoffs will have to be used to mount the embedded controller. Otherwise, there will be a direct electrical connection between the canister and the controller whichis unacceptable.

Attitude and Direction Sensor (YEI 3-Space)

TBD TBD

G-SwitchThe G-switch will be mounted to an L-bracket that is attached to the chassis plate with 8-32 screws..

The connecting wires will be soldered to the G-switch and to the PDB

RockSat-C 2012PDR

System Overview – RockSat-C 2012 User’s Guide Compliance

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The mass of our entire payload will be less than half the total allowable mass of 20.0 lb which includes the canister mass.

The center of gravity is yet to be established

We are using DC circuits with a maximum voltage requirement of 20 VDC and 300 mA

We require 1 optical port

RockSat-C 2012PDR

System Overview – Sharing Logistics

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Who will you be sharing a canister with ?

We will be sharing our canister with Frostburg State University.We don’t know yet what their project is.

Plan for collaboration -- How do you communicate?

We sent them a preliminary plan by email and they haven’t responded.

How will you share designs (solidworks, any actual fit checks before next June)?

We will send our SolidWorks drawings to them and communicatewith them via email and phone.

Structural interface – will you be joining with standoffs or something else (again, be wary of clearance)?

We don’t know what our sharing arrangements will be.

grandpmr.com

RockSat-C 2012PDR

System Overview – EPS: Risk Matrix

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Consequence

Entire mission fails Partial Mission failure Little to no data collected

Once above clouds, measurements will

be successful

G-Switch doesn’t activate electronics

Batteries drain before end of flight

Microcontroller has malfunction

Sunlight too low due to cloud cover

Possibility

RockSat-C 2012PDR

Prototyping Plan

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RockSat-C 2012PDR

Prototyping Plan

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Concern about over saturating the detector or

not enough light

EPP 2000 UVN-SR

YEI 3-SPACE

G-Switch

TERN EL

Not sure of how to use attitude and direction finder

as it applies to rocket trajectory

Concern that G-Switch circuit will drain batteries prematurely

The functionality of the microcontoller board needs to be verified before CDR

Take spectra under various amounts of

Sunlight to find range

Use the sensor in order to understand how it

functions

Design and test a more robust G-Switch curcuit

Risk/Concern Action

Program microcontroller to test its ability to carry out its assignment.

RockSat-C 2012PDR

Project Management Plan

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RockSat-C 2012PDR

Project Management – Organizational Chart

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Bonnie Enix Software &

Testing

Joshua Griffith Software &

Testing

Will Waldron Hardware & Electronics

Edmond Wilson Mentor & Logistics

David Stair Technician & Graphic Artist

RockSat-C 2012PDR

Project Management – Schedule

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• What are the major milestones for your project?• (i.e. when will things be prototyped?)• CDR• When will you begin procuring hardware?• Think all the way to the end of the project!

• Rough integration and testing schedule in the spring• Etc, etc, etc

• Format:• Gant charts• Excel spreadsheet• Simple list• Whatever works for you!

Don’t let the schedule sneak up on you!

RockSat-C 2012PDR

Project Management – Budget

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Item Amount TotalCanister & Fees 7000 7000

Travel & lodging for launch week 1800/person 7200

Student Fellowship 8 weeks at 40 hr/wk

4000/student 12000

Materials & Components 1500 1500

Total $27,700

RockSat-C 2012PDR

Parcel out CDR template and begin creating CDR

Begin software development that will lead to operation of spectrometer, irradiance and attitude and direction sensors

Create primary canister plate and mount spectrometer to it

Learn to use Attitude and Direction Sensor

Seek additional funding from aerospace industries in Arkansas

Begin process of applying for an Arkansas NASA Workforce Development undergraduate Fellowship for each of the three student participants

Conclusion – Main Action Items

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RockSat-C 2012PDR

THE END!

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THANK YOU COSGC & WFF!