The team presented a design for a 3U CubeSat called ROCKY to measure lift, drag, magnetic fields, radiation, and GPS performance in low Earth orbit (LEO). Key features of the design include actively controlling descent into the atmosphere to maximize time in LEO using a Vacco Palomar micropropulsion system. Subsystems presented included a Bartington Spacemag magnetometer, Teledyne UDOS007 radiation dosimeter, Radius 3U structure, MAI 400 attitude determination and control system, and components from partners including a propulsion system from Tuskegee University. The team used agile processes and decision analysis to select components to meet requirements within a $1.52 million budget and launch

1. SDR BRIEFING
ROCKY
TEAM CD

2. ROCKY
Goal: Design and Develop a 3U CubeSat
 Measures lift, drag, magnetic fields, radiation, and GPS
Performance in LEO
 Actively controls descent into the atmosphere to maximize
duration in LEO
Customer: U.S. Army Space and Missile Defense Command
Process: Agile SE processes
1

3. Team CD
PCE
Nathan
Sandlin
College of
Charleston
Team Lead
Wendell
Paul
AE
Ricardo
AE
Qioa
Environment
Austin
Sci Ops
Jeremiah
SCE
Justin
Sandlin
Thermal
Andrew
Tuskegee
Kiante’
Structure
Hagen
UTEP
Daniel
LSE
Janelle
Williams
ESTACA
Team Lead
Calin
Emeric
Antoine
Emilie
Yohann
PM
Eric
Powell
Luis
Aaron
Hugo
Team Lead
Christian
Kenneth
= UAH Engineering
= CofC Science
= Tuskegee Engineering
= UTEP Engineering
= ESTACA Engineering
2

4. Agenda
Requirements
Project
Science
Functionality
Environmental
Alternative Concepts
Decision Analysis
Final Decision
Based on Decision Analysis
Key Features
System Budgets
Mass
Power
Volume
Data
Initial Concept Draft
Engineering Draft
Interface
Subsystem Details
Thermal
ADACS
Communications
Partner Allocations
Programmatics
Semester Summary
Next Steps
3

5. Requirements
Project:
Specifications
 3U Cubesat < 10kg
 Volume no larger than 3U CubeSat
form factor
 Increase orbital lifetime by no less
than 10%
 Adhere to CubeSat Design
Specification Rev. 13
 Cannot violate any Space
Policy/Treaties
DRM:
 350 km circular orbit @ 28.5°
Additionally:
 Actively Controls Descent into
Atmosphere in LEO
Science:
Measures:
 Lift & Drag,
 Magnetic Fields,
 Radiation
 Location in orbit
Science Enhancement
 Measure radiation effects
through elliptical LEO
 Test possible methods of
shielding against radiation
4

6. Requirements
Functionality:
 Communicate with ground
station
 Send and receive data
 Can generate & distribute
self sustaining power
 Tumble
reduction/Stabilization of 3U
CubeSat
Environmental:
 Survivable in LEO
 radiation
 magnetic fields
 temperature fluctuations
 No space debris after 25 years
5

7. Developed for Evaluation
Alternative Concepts
GPS
Picosat NAV
piNAV-L1
piNAV-NG
Magnometer
MAG3110
Spacemag
Spacemag Lite
Radiometer UDOS0007
Propulsion
VACCO
Palomar
MEMS
Radio
SWIFT KTX
SWIFT XTS
LI-1
Heater
HK6915
HAP6948
HM6962
Structure
Clyde
Radius
ISIS
ADACS
BCT XACT
MAI 400
Cube ADCS
6

8. Weights of F.O.M
Best
OptionRaw score
Multi-Criteria Decision Analysis Method
Step 1: Identify and define a criteria for
selection
Step 2: Establish Weight Factors for each
criteria(1,3,9)
Step 3: Brainstorm different components
Step 4: Analyze different components
Step 5: Fill matrix for each component
Step 6: Calculate score for each component
Decision Analysis
7

9. Final Decision Concept
Our final of the available options resulted in the selection
of the following components:
1. Radius 3U Cubesat structure
since each offered similar specs, we opted for the low
cost solution
2. MAI 400 ADCS
A compromise of size and cost, with a high
survivability rating
3. piNAV-NG GPS module
low mass with high accuracy
4. Vacco Palomar micro propulsion system
8 independent thrusters with 6 DOF capability
5. Teledyne UDOS007 micro dosimeter
ultra compact and space flight heritage
6. LI-1 Radio Transceiver
low mass with low cost
7. HM6962 Heaters
most power efficient
8. Bartington Spacemag magnetometer
highest accuracy with low mass
8

10. Key Features
Magnetometer (SpaceMag)
Function:
 Altitude sensing as well
as measurement of
magnetic signature and
geomagnetic field mapping
Key Features:
 3-axis field of view
 Shock and vibration tested to
NASA-STD-7001
Measurement Range: (+/-)100𝞵T
Temperature Range: -55 to +125 (°C)
Mass: 175g
Power: 0.57W
Volume: 40 x 40 x 31mm
Dosimeter (UDOS007)
Function:
 Measure total ionizing dose (TID) of
radiation to estimate exposure rates of
other components
Key Features:
 Small volume and mass to provide
mounting for multiple locations
 Class K equivalent screening
Measurement Range:
100 keV to 15 MeV (Ionizing)
Temperature Range: -30 to 45 (°C)
Mass: 20 grams
Power:
13 to 40 (VDC)
Volume:
922.3248 (𝑚𝑚3)
9

11. Initial Draft
Top ViewFront View Side View
10

12. Component Interfacing
 Most sensors compatible with UART & 𝐼2 𝐶
 Physical Connections to be made with bolts
 Connections such as wires and heaters to be secured using adhesive and ties
11

13. Function:
 Automate Spacecraft by sending
Commands, Formatting and Saving Data
Key Features:
 MSP430 Microcontroller
Temperature Range: -40(°C) to 85(°C)
Mass: ~2 g
Power: 0.001 W
Volume: 0.173 𝑐𝑚3
Partners: UTEP
Command and Data Handling
12

14. Command and Data Handling
Function:
 Automate Spacecraft by sending
Commands, Formatting and
Saving Data,
Key Features:
 Kingston 16 GB SD card
Temperature Range: -25(°C) to 85(°C)
Mass: ~2 g
Power: ~ 0.3 W (during writes)
Volume: 0.614 𝑐𝑚3
13

15. Current Data Protocols
 UART
 I2C
 SPI
 Analog
Command and Data Handling
14

16. Propulsion (Palomar)
Function:
Provide propulsion to prolong mission
Key Features:
 Provides six degrees of freedom
 Eight independent thrusters
 Over 200,000 thruster firings in a
simulated space environment
Operating Parameters:
 Max Operating Pressure....150 psia
 Proof Pressure......................225 psia
 Burst Pressure.......................375 psia
 Thrust.....................................35 mN
 Internal Leakage ................3.0 scc/hr
 External Leakage................1.0 x 10 -6 scch
 Operating Temperature.... 0°C to +50°C
 Non-Operating Temperature
-10°C to +60°C
 Vibration..............................23 Grms
Cycle Life ..........................120,000 firings
Total Impulse..................... 85 N/sec
Minimum Impulse Bit……. 0.75 mN/sec
Operating Voltage ……...4.75 to 5.25 vdc
Peak Power......................<5 watts (2 thrusters)
Dry Mass............................ 890 grams
Propellant Mass ……....... 173 grams
Total Mass ..................... 1,063 grams
15

17. Power
Function:
 Collect and distribute power
across spacecraft
Key Features (components):
 NanoPower P110 Solar panels
Temperature Range: -40(°C) to 85(°C)
Mass: 26 g
Power: 2.3 W/package
Volume: 8.9 𝑐𝑚3
Partners: UTEP
16

18. Power
Function:
 Collect and distribute power
across spacecraft
Key Features (components):
 CubeSat Kit Battery Module 1
Temperature Range: -40(°C) to
85(°C)
Mass: 310 g
Power(Capacity): 40 W hr
Volume: 225 𝑐𝑚3
Partner: UTEP
17

19. Structure
Function:
 Housing and
protection from any debris,
radiation, and temperatures while
in LEO
Temperature Range: -170°C to 123°C
Mass: 255 grams
Volume: 340.5mm X 100mm X 100mm
Key Features:
 Frame: Aluminum 7075
anodized, hardcoat, and
Alodine 1200.
18

20. Communications
Function :
 Transmit data and receive
commands to and from ground
station.
Key components: LI-1Radio
Estimated Mass: 52 grams
Volume: 21.45 𝑐𝑚3
Operating Temp: -30(°C) to + 70(°C)
Frequency: 130-450 MHz
Partners: UTEP
19

21. Communications
Function:
 Transmit data and receive
commands to and from
ground station.
Key components: ISIS UHF Antenna
Estimated Mass: < 100 grams
Volume: 6.7 𝑐𝑚3
Operating Temp: -30 (°C) to + 70 (°C)
Frequency: 130-500 MHz
Partners: UTEP
20

22. Thermal
 Function:
 Maintain operating temperature ranges
on board the CubeSat
 Key Features (components):
 Polymide Thermofoil heater
 Temperature Range:-150(°C) to 600 (°C)
 Mass: 141 g
 Power: ~7.5 W (maximum)
 Volume: 29 𝑐𝑚2
21

23. ADACS
 Function: Stabilize & aim the CubeSat
 Key components: MAI 400
 Estimated Mass: 694 grams
 Estimated Power :
 Steady State/ Typical W: 3.17
(0.63amps @ 5V)
 Peak Wattage: 7.23 (145 amps @ 5V)
 Volume: 10x 10 x 5.9cm
 Partners: Tuskegee University
22

24. Partner Allocations
UTEP CofC ESTACA Tuskegee
23

25. University of Texas, El Paso (UTEP)
Communication:
• 2 Video Conferences & email
• Responsible for Power and C&DH
subsystem
• Expertise: Team of senior electrical
engineering majors
Tasks:
• Create Data budget based on
sensors, processor, and memory sizing
• Provide flow diagram showing data
interfacing and power connections
• Calculate data transmission limits
between CubeSat and ground
station
24

26. College of Charleston (CofC)
Budget
 Assigned a minimal
budget including:
 Mass for science
enhancement to be
kept below 0.5 kg
 Power will be less
than 1 Watt, not
including required
orientation
maneuvers.
 Allowable data
usage will be
determined by UTEP
 Interfaces must
communicate
directly with C&DH.
Tasks
 Responsible for the
science
enhancement
objective
 Will attempt to
determine the
effectiveness of
different methods of
radiation shielding
 Requesting the use
of elliptical orbit
 Requires pointing
ability of the
cubesat to provide
best radiation test
data
Communication
 Area was
recovering from
tropical storm
during semester
 Email
communication has
been unreliable at
best
 Held a video
conference with the
entire team
25

27. ESTACA
Current collaboration done by email, video networking in future
ESTACA future deliverables
Orbital analysis
Model varying velocity and acceleration based on CubeSat dimensions
Determine an average rate of decay depending of change in mass and
velocity
Time ratio of sun contact and change in internal energy for solar power
26

28. Programmatics
Total Estimated Cost: $1.52 Mil
System US$
Structure 5,330.00$
Propulsion 138,260.00$
ADACS 118,000.00$
Thermal 977.30$
Communication 11,570.00$
Payload Sensors 99,130.00$
Pow er 2,000.00$
Command and Data 27.00$
Man Hours 1,139,200.00$
Total Estimated Cost 1,514,494.30$
3U CubeSat Cost: $ 375,295
No current compliance issues. 27

29. Programmatics
April May July Oct Dec Jan 28

30. RDR Sprint
 Defined program
requirements for the
cubesat and the
subsystems
 Defined driving
requirements
 Defined Perturbations in
requirements
 Gained knowledge of
state of the art cubesat
technology
ADAR Sprint
 Developed Figures of
Merit for the cubesat
and subsystems
 Used decision analysis
technique to determine
solutions
 Developed alternatives
for subsystems
 Defined key
performance
parameters for partners
 Determined key risks
SDR Sprint
 Determined concept that
satisfied requirements
 Partner requirements
 Developed Component
breakdown
 Provided preliminary cost
for the program
 Provided preliminary
schedule for the program
 Identified key risks
Semester Summary: Agile
29

31. 1. Finalize Detailed Design using
CATIA or other software
2. Complete Bill of Materials for
ordering components
3. Order Components
4. Apply for Ham License
5. Apply for flight approval
6. Complete Risk-Mitigation
Analysis
7. Build prototype for testing
8. Finalize ROCKY and prepare
for flight
9. Upon successful deployment,
collect and analyze data for
life span of ROCKY
Next Steps
30

32. “
”
Design is not just what it looks like
and feels like.
Design is how it works.
STEVE JOBS