2013 CDR

UMN Rocksat Critical Design Review

University of Minnesota Philip Hansen, Viet Nguyen,

Abdi Jama, Yusuf Abdi 12/9/2012

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CDR Presentation Outline

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• Section 1: Mission Overview • Section 2: Design Description • Section 3: Subsystem Design • Section 4: Prototyping/Analysis • Section 5: Manufacturing Plan • Section 6: Testing Plan • Section 7: User Guide Compliance • Section 8: Project Management Plan

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1.0 Mission Overview

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Mission Overview

• The Determination of the effect of a suborbital rocket flight on various electrical components due to radiation Damage

• Expect that the semiconductor will be damaged with space flight

• This will benefit future space craft design to compensate for radiation damage to semiconductors

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Theory and Concepts

•  Radiation damages the crystal by increasing the number of charge carriers in the crystal as the charge carriers accumulate the Semiconductor changes slowly into a conductor and becomes unusable

•  The defects in the semiconductor caused by radiation can be detected in two types of structures during flight they are a Crystal Oscillator and Flash memory

•  Radiation damage in a crystal oscillator can be detected via a permanent change in the Crystals oscillating point and is permanent

•  Radiation Damage in flash increases the number of errors in a flash memory as damage accumulates

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Mission Requirements:

Objective Requirements

Monitor Crystal oscillator errors Caused by radiation (O1)

Construct a sensor that will measure frequency deviations between two oscillators

Monitor Flash memory for bit errors caused by radiation(O2)

Construct a device to take an active error count of a flash memory

Store a log of radiation Damage as it happens(O3)

Construct a Device that will store the values that are determined in O1 and O2

Meet Rocksat-X Design Requirements

Ensure O1,O2,and O3 follow design requirements in user guide

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Success Criteria:

–  The oscillator subsystem will deliver their frequency changes of crystal oscillators and store that information to protected flash memory. The powered down flash will show radiation damage after the flight when ground inspection is performed

–  The powered up flash will show increasing errors while

in flight and the oscillator Crystals will show damage while in flight relative to shielded modules

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Expected Results

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• During the flight we expect to see a permanent damage to the crystal oscillator frequency that will change the oscillation point by about a tenth of the crystals rated oscillating frequency

• The Flash Memory will show damage from the flight that will manifest itself as bit errors in the read back data

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Concept of Operations

•  While in flight the Payload will continuously collect data looking for damage to the Semiconductors caused by radiation in flight. This Data should give us a crude understanding of how radiation damage occurs while within suborbital space

•  The Power is on at 6 minutes prior to launch taking data then at 450 seconds stores the data and prepares to land

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Concept of Operations

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Event  Time  On   Units  

Dwell  Time   Units   Event  Descrip3on  

GSE  1   5  (T-­‐X)  (min)       (min)   Used  for  Primary  power  all  systems  power  on  

GSE  2   4  (T-­‐X)  (min)       (min)  

Used  for  Backup  power  connec>on  all  systems  on  if  primary  connec>on  fails  

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ConOps

t ≈ 876 sec

Splash Down

-G switch triggered

-All systems on

-Begin continual data collection

t = 0 min

Apogee

t ≈ 199.7 sec

Altitude: ≈153 km

End of Malemute Burn

t ≈ 28.7 sec

Altitude: 17.2 km

t ≈ 450 sec

Computers shut down and store

data

Altitude

t ≈ 454.9 sec

Chute Deploys

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2.0 Design Description

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Actions from PDR

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• Have begun communications with flight deck partners

• Designed a first revision of all systems • Improved the Block diagram,

ConOps description, and Mechanical drawings

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Changes Since PDR

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• We have changed the Microcontrollers from the PIC18F4550 à PIC18F4480 and from PIC18F2550à PIC18F2480 this is to reduce the need for CAN Controller Chips

• Added a Real Time Clock(RTC) to the Data logger and Block Diagram

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Design Overview: Functional Block Diagrams

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Mechanical Design Elements

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• The Payload will have multiple stacked circuit boards with flash memory chips and Crystal Oscillators as sensors

• There have been solid works models created for this design

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Mechanical Drawings

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3D image of our payload

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Electrical Design Elements

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•  The system takes data via several microcontrollers and then transmits that data over the CAN bus to two data loggers

•  The system is broken into four primary repeatable modules. These modules are the Data Logger, Oscillator experiment subsystem, Flash experiment subsystem, and the power subsystem

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System Electrical Diagram

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Software Design Elements

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• Computers start up and begin collecting data through the sensors

• Data is sent over the CAN Bus to the Data loggers

• The data is then appended with a time stamp

• The data is store to permanent memory on the data logger

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De-Scopes and Off-Ramps

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• This is entirely implemented in circuitry some of the CAN networking elements can be removed and the data stored to local SD cards by the subsystems

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3.0 Subsystem Design

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Organizational responsibilities •  Philip Hansen – Team Lead/Power/CAN/Documentation •  Viet Nguyen – Structural / Mechanical •  Abdi Jama - EE Lead/SPI interface/Flash/Oscillator •  Yusuf Abdi - Data Logger/RTC

•  Ted Higman – Faculty Advisor / Finances

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Oscillator Subsytem

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Oscillator Subsystem

• Mechanically this is placed on a PCB that is connected to the power and data logger subsystems via the Power Bus and the CAN Bus

• Mass Estimate 0.3 lbs per block

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Oscillator Subsystem Power estimate

• The power estimate for this block is 0.002Ah per block

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Flash Subsytem

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Flash subsystem

• Mechanically this is placed on a PCB that is connected to the power and data logger subsystems via the Power Bus and the CAN Bus

• Mass estimate 0.3lbs per block

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Flash Subsystem Power estimate

• The power estimate for this block is 0.004Ah per block

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Datalogger Subsystem

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Datalogger subsystem

• This block receive all data and stores it to protected memory. This is mounted on A PCB

• Mass estimate 0.75 lbs per block

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Datalogger Subsystem Power estimate

• The power estimate for this block is 0.02Ah

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Power Subsystem

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Power subsystem

• This is the Power distribution subsystem • Mass estimate 0.1 lbs • This system is duplicated once per power

rail

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Power Subsystem Power estimate

• The power estimate for this block is 0.02Ah per block

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4.0 Prototyping/Analysis

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Analysis Results

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• The system has yet to be modeled or analyzed since this is Primarily a Electronics Payload that Is vary Flexible

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Prototyping Results

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• Currently the Flash interface is being prototyped

• The hardware will be prototyped as a step in writing the Code for the Microcontrollers

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Detailed Mass Budget

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Mass  Budget  Subsystem   Total  Mass  (lbf)  

Flash   2  Datalogger   1.5  Oscillator   1.2  Power   0.2  …  …      …      …              Total   3.9  Over/Under   11.1  

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Detailed Power Budget

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ExampleSat  Power  Budget  Subsystem   Voltage  (V)   Current  (A)   Time  On  (min)   Amp-­‐Hours  

Power   0   0.11   12.5   0.02  Dataloggers   5   0.02   12.5   0.013  Oscillator   5   0.01   12.5   0.008  Flash   5   0.01   12.5   0.016  …                  …                  …                  …                                      

Total  (A*hr):   0.03  Over/Under   0.97    

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Wallops Interfacing: Power

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Power  Connector-­‐-­‐Customer  Side  Pin   Func3on  1   Primary  Power  2    Not  Used  3    Not  Used  4    Not  Used  5    Used  for  Power  GND  6    Used  for  Power  GND  7    Used  for  Power  GND  8    Used  for  Power  GND  9    Auxiliary  Power  10    Not  Used  11    Not  Used  12    Used  for  Power  GND  13    Used  for  Power  GND  14    Used  for  Power  GND  15    Used  for  Power  GND  

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Wallops Interfacing: Telemetry

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• All the telemetry pins are unused

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5.0 Manufacturing Plan

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Mechanical Elements

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• PCB will be manufactured for this project • They will connect to a standard Rocksat-x

Flight deck

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Electrical Elements

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• PCB’s will need to be soldered • 2 Revisions are planned • All electrical parts need to be procured • The Schematics need another revision prior

to integration then there will be a layout phase and a prototype build

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Software Elements

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•  The code needs two communication blocks a CAN connection, and SPI connection. All other code depends on these blocks.

•  There needs to be data taking code for the Flash experiment and Oscillator experiment.

•  There needs to be code that integrates the Real time clock and Flash memory.

•  There needs to be code that stores CAN information to the Flash memory

•  This code will be prototyped with the Prototype build

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6.0 Testing Plan

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System Level Testing

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• Consider system level requirements that need to be verified

• Present a brief overview of the tests you need to conduct to verify these requirements

• When will these tests be performed?

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Mechanical Testing

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•  Ensure PCB’s can handle all physical strains in flight

•  Ensure Physically the payload handles all predictable forces during flight

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Electrical Testing

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• Need to verify all communication buses are working properly.

•  The Flash and RTC need to be verified for operation

•  The main power regulators need to be verified that they are producing the desired output

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Software Testing

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• CAN and SPI interface instructions combined with the Flash and Real Time clock code need to be written prior to hardware Testing

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7.0 User Guide Compliance

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User Guide Compliance

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Requirement   Status/Reason  (if  needed)  Center  of  gravity  in  1"  plane  of  

plate?   unknown  

Max  Height  <  6"      

Within  Keep-­‐Out      

Using  X  GSE  Line(s)   1  (per  requirement)  

Using  X  Redundant  Power  Lines   1  (per  requirement)  

Using  X  Non-­‐Redundant  Power  Lines   2  (one  extra)  

Using  <  1  Ah   Well  under  

Using  <=  28  V   Well  Under  

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Sharing Logistics

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•  Northwest Nazarene University •  Currently, communicating with Email •  Probably joining with standoffs •  No meetings yet •  Benjamin Gordon - bendoo02@gmail.com

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8.0 Project Management Plan

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Schedule

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•  We are using simple lists to keep track of what needs to be done

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Budget

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Category Unit price Quantity Total Flash Subsystem

$15.00 4 $60.00

Oscillator subsystem

$10.00 4 $40.00

Power subsystem

$5.00 2 $10.00

Datalogger subsystem

$20.00 2 $40.00

Total $150.00

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Team Availability Matrix

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•  Spring 2013 semester schedules still are being determined •  Central standard time

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Contact Matrix

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• Using the plans outline above we plan to implement a device that can determine the Effect of radiation on semiconductors while in suborbital flight

Conclusion

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