Verification Method

Electron Losses and Fields
Investigation
Subsystem PDR
Mechanical/Structural Subsystem
Christopher Yu
Los Angeles, California
December 1, 2014
1
REVIEW BOARD MEMBERS
Name
Organization
Andrew Lamborn
JPL
Marc Lane
JPL
2
MECH PEER PDR REVIEW
Science Overview
Vassilis Angelopoulos
Los Angeles, California, October 23, 2014
3
OBJECTIVE
AND
SCOPE
OF
PDR
peer PDR objective: demonstrate design meets requirements
peer PDR is an opportunity for design team to:





Show well defined subsystem scope and responsibilities
Show clear definition of personnel roles and responsibilities
Expose design to experts in an open and relaxed environment where
technical discussions can take place
Identify potential engineering and implementation flaws to increase
probability of success by taking corrective action early in program
Provide feedback on the detailed design of the subsystem
peer PDR chair will coordinate review team minutes as follows:



Request for action (RFAs) by team, closed after initiator concurrence
Recommendations, to be considered without need for closure by initiator
Observations, points of information to be noted in the review report
4
MECHANISMS TEAM
Name
Responsibility
year
Christopher Yu
Team Lead + Harnessing Lead
2
Noah Kang
Harnessing
1
Priscilla Tsui
Harnessing
2
Anthony Gildemeister
Harnessing
2
Gary Chao
Static Lead
3
Eric Qu
Static
1
Erica Chung
Vibe Lead
3
Guillerme Albertini
Vibe
1
Nathan Chung
Vibe
3
Arada Dermegerderchian
Vibe
2
Daniel Lee
Mech Lead
4
Katie Murphey
Mech + Student Advisor
4
5
MECH TEAM ORGANIZATION
6
EXPLODED VIEW
7
TABLE












OF
CONTENTS
Requirements
Operational Concept
Structural Organization
Chassis Design
Avionics Unit Design
Assembly Procedures
Finite Element Analysis
Mechanisms
Harnessing
Implementation Schedule
Safety/ Facilities
Problems
8
Requirements and
Specifications
9
STRUCTURES REQUIREMENTS
REQ ID
STRC‐01
STRC‐02
STRC‐03
STRC‐04
STRC‐05
STRC‐06
STRC‐07
STRC‐08
Requirement
Parent(s)
Aluminum alloys used in structural applications shall SYS‐25
be resistant to general corrosion, pitting, intergranular
corrosion, and stress corrosion cracking.
ELFIN shall be capable of constraining all deployables SYS‐25
Rails shall have a minimum width of 8.5mm.
SYS‐25
The rails shall not have a surface roughness greater SYS‐25
than 1.6 μm.
The edges of the rails shall be rounded to a radius of SYS‐25
at least 1 mm
The ends of the rails on the +‐X face shall have a minimum surface area of 6.5 mm x 6.5 mm contact SYS‐25
area
At least 75% of the rail shall be in contact with the P‐
POD rails. 25% of the rails may be recessed and no SYS‐25
part of the rails shall exceed the specification.
Aluminum 7075, 6061, 5005, and/or 5052 shall be SYS‐25
used for both the main structure and the rails.
Verification Method
I: inspection
I: inspection
I: inspection
I: inspection
I: inspection
QA inspection
Design and QA inspection
Design and QA inspection
10
STRUCTURES REQUIREMENTS
REQ ID
Requirement
Parent(s)
The CubeSat rails and standoff, which contact the P‐POD rails and adjacent STRC‐09 CubeSat standoffs, shall be hard anodized SYS‐25
aluminum to prevent any cold welding within the P‐POD.
All antennas shall be capable of deploying STRC‐10
while ELFIN is tumbling.
SYS‐25
The ratio of the major moment of inertia to STRC‐11 the intermediate moment of inertia shall be SYS‐25
greater than 1.2
The structure shall not use magnetic SYS‐21
STRC‐12
materials.
The spacecraft shall be capable of deploying SYS‐25
STRC‐13
the stacer
The center of gravity shall be located within 2 cm from its geometric center in the Y and Z SYS‐25
STRC‐15 directions
Verification Method
I: inspection
Thorough testing of all deployable antennas to ensure a minimum 99.9% success rate.
CAD and spin testing.
T: magnetic cleanliness testing
CAD
CAD
11
STRUCTURES REQUIREMENTS
REQ ID
Requirement
The center of gravity shall be located within 7 cm from its geometric center in the X direction.
The length, rotations and bending of the stacer shall be STRC‐17
known to at least TBD cm
The Structures subsystem shall not exceed the mass STRC‐18
allocated by Systems
The Structures subsystem shall not exceed the power STRC‐19
allocated in the ELFIN system power budget
STRC‐16
Parent(s)
SYS‐25
SYS‐25
Verification Method
CAD
deployable tests
SYS‐14
CAD
SYS‐22
Documentation
12
Spacecraft Operational
Concept
13
OPERATIONAL CONCEPT
Structures/Mechanisms Timeline:
1. Exit from PPOD (1 minute)
2. Deploy antennas (12-24 hours)
3. Deploy stacer (2nd day to 2 weeks)
14
Spacecraft Structural
Organization
15
ORGANIZATION
▪ Divided into three
subunits
▪ Avionics
▪ Stacer
▪ Energetic Particle
Detectors
16
MAJOR COMPONENTS
Torquer Coils
▪ Integrated with chassis as additional
structural element
▪ Also used for mounting components
Stacer Assembly
▪ Helps with structural stability of
the spacecraft
▪ Replaces the original cross braces
found in the Tensor-82 chassis
17
MASS REQUIREMENT - STRUCTURES
REQ ID
STRC‐18
Requirement
Parent(s)
The Structures subsystem shall not exceed the mass allocated by Systems
Structures & Mechanisms
Component
Chassis
EMI shield
Battery holder
Fasteners
Brackets
Antenna holder
Tuna can
Harnessing
Stacer
Maturity
P
P
P
P
P
P
P
L
P
SYS‐14
Qty
1
1
1
1
1
1
1
1
1
Verification
T: Components will be weighed
Unit mass
220.93
41.00
60.00
57.35
32.00
6.16
27.47
50.00
386.00
CBE
220.9
41.0
60.0
57.4
32.0
6.2
27.5
50.0
386.0
Verification Document
Mass Budget
Margin
15%
15%
15%
15%
15%
15%
15%
20%
15%
CBE+Margin
254.1
47.2
69.0
66.0
36.8
7.1
31.6
60.0
443.9
Mass allocated for Structures & Mechanisms: 1020 g
Current best estimate (CBE): 880.9 g
Margin: 15.6 % (134.6 g)
CBE + Margin: 1015.5 g
Contingency: 4.5 g
18
Chassis Design
19
MATERIAL SELECTION
REQ ID
STRC‐08
Requirement
Parent(s)
Aluminum 7075, 6061, 5005, and/or 5052 shall be used for both SYS‐25
the main structure and the rails.
Verification Method
Verification Document
014‐
Design and Al_Alloy_tradestud
QA inspection
y‐00
6061 vs. 7075
 7075 has more promising mechanical properties
 6000 series has excellent corrosion resistance to the 7000 series
 Cost/mass tradeoffs from using 7075
 level of machinability
Notable Statistics
6061-T6
7075-T6
Tensile Yield Strength mPa (@100C)
275
434
Tensile Yield Strength mPa (@-80C)
310
503
Cost (12’’x12’’x1’’) USD
412
635
Density (g/cc)
2.7
2.81
20
CHASSIS V1
▪ Original Chassis Design
▪
▪
▪
▪
Aluminum 6061-T6
Based off the Boeing Tensor 82 Chassis
Customized to reduce mass, mounting brackets added
Four cross braces connecting the two side frames
21
CHASSIS V1 PROBLEMS
Problem
Solution
Back out from screws connecting
the cross braces to the side
frames
Implement helicoils in the
necessary locations in the chassis,
and utilize chemical adhesives
Torsion and parallelogramming in
xy plane
Eliminate cross brace design
Lack of structural integrity in cross
braces
Eliminate cross brace design
22
CHASSIS DESIGN V2
REQ ID
STRC‐
03
STRC‐
04
STRC‐
05
Requirement
Rails shall have a minimum width of 8.5mm.
The rails shall not have a surface roughness greater than 1.6 μm.
The edges of the rails shall be rounded to a radius of at least 1 mm
The ends of the rails on the +‐X face shall have a STRC‐
minimum surface area of 6.5 mm x 6.5 mm contact 06
area
At least 75% of the rail shall be in contact with the P‐
STRC‐
POD rails. 25% of the rails may be recessed and no 07
part of the rails shall exceed the specification.
Parent(s)
Verification Method
SYS‐25
I: inspection
SYS‐25
I: inspection
SYS‐25
I: inspection
SYS‐25
QA inspection
SYS‐25
Design and QA inspection
Verification Document
Chassis Isometric View
23
CHASSIS DESIGN V2
▪
▪
▪
▪
Addresses problems arisen from UNP EDR
Easier machinibaility
Side rails rounded with fillet of 0.050 inches
Less-than flush top hat allows for maximum PPOD rail contact
24
CHASSIS DESIGN V2
Rail Drawing View
25
CHASSIS DESIGN V2
Top Hat Drawing View
Top Hat Trimetric View
26
Avionics Unit Design
27
AVIONICS UNIT OBJECTIVES
REQ ID
Requirement
STRC‐12 The structure shall not use magnetic materials.
Parent(s)
SYS‐21
Verification Method
T: magnetic cleanliness testing
Verification Document
Design Goals:
▪ Houses the 4 Li-ion batteries
▪ Fill a single U of the total 3U
▪ Contain the necessary 7 PCB’s
and He-82 Radio
▪ Encased in EMI shield
▪ Allow for harnessing ease to the
EPD boards and –X panel
Avionics Unit Isometric View
28
AVIONICS UNIT OVERVIEW
Avionics Stack
Li-Ion Batteries
Radio
29
BATTERY HOLDER REDESIGN
V1 Isometric
▪
▪
▪
▪
▪
V2 Isometric
Increased cupping of ends of battery cells
Increased strength of mounts
Large divots next to the battery terminals for easier harnessing access
Holes in top and bottom mount for securing EMI shield
Realistic machinability
30
Assembly Procedures
31
ASSEMBLY PROCEDURES
REQUIREMENTS
Objective: Document the spacecraft-level assembly procedures.
Success Requirement: Document can be followed, through assembly with 3D
printed components
▪
▪
Each step will have a list of required parts and the bolt’s torque specs.
Torque specs will abide to MSFC-STD-486B
32
EPD
AND
AVIONICS UNIT
33
INTEGRATING SUBASSEMBLIES
34
INTEGRATING SUBASSEMBLIES
35
INTEGRATING SUBASSEMBLIES
36
INTEGRATING SUBASSEMBLIES
37
SOLAR PANEL
AND
X PANELS
38
SPACECRAFT CONFIGURATIONS
REQ ID
STRC‐15
STRC‐16
Requirement
Parent(s)
The center of gravity shall be located within 2 cm from its geometric center in SYS‐25
the Y and Z directions
The center of gravity shall be located within 7 cm from its SYS‐25
geometric center in the X direction.
Stowed:
Y: -.025cm, Z:-0.051cm
Verification Method
CAD
CAD
Deployed:
X: 0.377cm
39
SAMPLE PAGE
40
Static FEA
41
STATIC SIM REQUIREMENTS
REQ ID
Requirement
Verification
Method
Verification Document
002-StructuralAnalysis2014-04R.doc
UNP 3
The SV shall be designed using the MAC
curve.
SolidWorks
Simulations
UNP 4
Factor of safety to be used are 2.0 for yield
and 2.6 for ultimate for structural design
and analysis.
SolidWorks
Simulations
002-StructuralAnalysis2014-04R.doc
Other Desired Simulation Requirements:
•Test in all 6 directions
•Old sim uses 55g’s of acceleration
•New sim uses 50g’s of acceleration
•Survival of launch conditions
Titan IV MAC Curve
42
SIMULATION OVERVIEW
REQUIREMENTS
▪ Chassis:
▪
Simplified: suppressed some
fillets, removed non-structural
elements
AND
▪ Materials:
▪
▪
Aluminum 6061-T6 for most of the structure
Highlighted parts, the torquer coil spools, are
PEEK
43
SIMULATION OVERVIEW
REQUIREMENTS
AND
▪ Fixtures:
▪
▪
One “Fixed Geometry” (blue), one “On Flat Face” (green)
Allows for movement in the other two axes
44
SIMULATION OVERVIEW
REQUIREMENTS
AND
▪ External Loads:
▪
▪
“Gravity” load to simulate acceleration in the chosen axis
“Remote Mass” for the EPDs, which are the heaviest
instrument
45
DISTRIBUTED MASSES
▪ External Loads, cont.:
▪
“Distributed Masses” for the other components: radio, panels,
torquer coils, all PCBs
46
BOLT CONNECTIONS
▪ Bolts:
▪
▪
▪
Bolt connections were used where applicable, and in areas of interest
With bolt connectors, contact sets were set to “No Penetration”
Global bonding throughout the structure
47
MESH
▪ Solid Mesh:
 Mesh Control:
▪
▪
▪
▪



Element size: ~0.22 in  ~0.19 in
Number of elements: ~75,000  ~520,000
Degrees of freedom: ~330,000  ~2,700,000
Number of nodes: ~110,000  ~900,000
Coil element size: ~0.025 in
Rail element size: ~0.035 in
Reason: To have at least two
elements along the edges
48
OLD SIMULATION RESULTS
Simulation Results
Stresses
Factor of Safety
Axis of Applied Acceleration
Max Von Mises Stress
Min Factor of Safety
+X
112 MPa
2.3
-X
180 MPa
1.5
+Y
119 MPa
2.1
-Y
126 MPa
2.2
+Z
112 MPa
2.4
-Z
111 MPa
2.3
Aluminum 6061-T6
Strengths
Tensile Yield Strength
Ultimate Yield Strength
275 MPa
345 MPa
49
-X
OLD SIM
(VON
MISES)
-X axis
50
PROBLEMATIC AREAS


Zoom of the lowest FOS, found on a
cross brace in the -X axis simulation
Minimum factor of safety of 1.53
51
V1
SOLUTIONS
Summary of Further Simulation Results for –X external gravity load
test
Description
Min FOS
1
Increased radius of fillet of cross braces to 0.035in
1.56
2
Increase radius of fillet of cross brace to 0.070in
1.91
3
Increase Y normal extrusion of both +X cross braces by 50 mil
1.98
- Increase Y normal extrusion of +X –Y cross brace by 50mil
4
- increase the y normal extrusion of the +X +Y cross brace by 75 mil
2.10
- increase fillet of cross braces to 0.035in
*Ultimately disregarded cross brace design because of machinability
52
NEW STRUCTURE SIMULATIONS




Used chassis v2 while also changing simulation parameters to 50g’s
of gravity.
Chassis v2 was simplified by eliminating negligible structural
elements (e.g. small brackets, rail tabs).
Additional bolt connectors were added for accuracy.
Redefined and added contact sets to increase accuracy.
53
-X
NEW SIM
-X axis
54
-X

NEW SIM
Zoom of the lowest FOS, found on
the top hat structure in the -X axis
simulation
55
+Z
NEW SIM
56
+Z

NEW SIM
Zoom of the lowest FOS, found on the
tab of the bottom chassis rail in the +Z
axis simulation
57
NEW STRUCTURE SIMULATIONS
Simulation Results
Stresses
Factor of Safety
Axis of Applied Acceleration
Maximum Von Mises Stress
Minimum Factor of Safety
-X
56.7 MPa
3.29
+X
64.1 MPa
4.29
-Y
39.0 MPa
7.04
+Y
54.5 MPa
3.48
-Z
66.7 MPa
4.12
+Z
124.0 MPa
2.22
Structural Element
Material
Yield Strength
Chassis Rails
Aluminum 6061-T6
275 MPa
Torquer Rails
PEEK Compression Mold
89.6 MPa
58
FUTURE PLANS
 Rerun static sims with future revisions of the
chassis
59
Modal Analysis
60
MODAL ANALYSIS OVERVIEW
REQUIREMENTS
AND
 SolidWorks Simulation 2013
 Frequency Analysis
 UNP requirement to find the first mode of
spacecraft
61
SIMULATION MODEL OVERVIEW
 Chassis:
 Simplified chassis model:
removed all holes and tabs
 Removed all units and replaced
with remote loads (stacer, EPD)
and distributed masses
(Avionics, Solar Panels, Torquer
Coils, MAG Board)
 Materials:
 Chassis and top hats made of
Aluminum 6061-T6
62
SIMULATION
MODEL
FIXTURES
 Fixed geometry on 1 face (blue), roller/slider on 1 face (green)
to allow for freedom in movement in 2 axes to represent
movement in P-POD
63
FIRST FIVE MODES
Mass Participation
Mode
No. Frequency (Hz)
X direction
Y direction
Z direction
1
168
6.63E-05
1.41E-01
3.38E-07
2
183
6.58E-05
5.93E-02
3.89E-05
3
386
9.35E-05
1.99E-05
2.20E-02
4
419
3.85E-04
4.83E-05
8.49E-02
5
510
1.04E-04
3.74E-05
2.35E-08
First Mode(168 Hz)
Note:
Displacement magnitudes are arbitrary.
64
OTHER
Second (183Hz)
Fourth (419Hz)
MODE
DISPLACEMENTS
Third (386Hz)
Fifth (510Hz)
Note:
Displacement magnitudes are arbitrary.
65
Vibe FEA
66
RANDOM VIBRATIONS FEA
OVERVIEW AND REQUIREMENTS
 SolidWorks Simulation 2013


Simulate random vibrations in P-POD
Testing in all 6 directions

Input based on chart below from NASA Finite Element Modeling continuous
Improvement (FEMCI) book and NASA General Environment Verification Speciation
(GEVS)
67
ADDITIONAL FIXTURES
APPLIED LOAD
FOR
 Load being applied is the Uniform Base Excitation
 Additional fixtures will change location depending on the
direction of the load being tested
 For uniform base excitations in +X direction, fixtures were
placed on the -X end caps, with 3 roller/sliders (green) and 1
fixed geometry (blue) in addition to the previous fixtures
68
MESHING
 Solid Mesh:
 Mesh sizing based on rule of thumb of 2 elements per thinnest structural
element and 2 elements per 90° arc
 194,597 elements
 328,084 nodes
 Element size: 0.124 inch (except where mesh controls are applied)
69
RESULTS:
(+X)
VON
MISES STRESSES
Probabilities of
Non-Excedance
68.3% of cases
within
95.5% of cases
within
99.7% of cases
within
Von Mises Stress
± 0.926 MPa
± 1.852 MPa
± 2.778 MPa
70
RESULTS: DISPLACEMENTS (+X)
Probabilities of
Non-Excedance
68.3% of cases
within
95.5% of cases
within
99.7% of cases
within
Displacement
± 688 nm
± 1380nm
± 2060 nm
71
RESULTS
IN
OTHER DIRECTIONS
Yield Strength: 275MPa
Direction
Probabilities of
Non-Exceedance
68.3% of cases
within
95.5% of cases
within
99.7% of cases
within
-X
Von Mises Stress
±0.543MPa
±1.09MPa
±1.63MPa
Displacement
±829nm
±1,660nm
±2,490nm
Von Mises Stress
±12.5MPa
±37.4MPa
±37.4MPa
Displacement
±3,75nm
±7,500nm
±11,300nm
Von Mises Stress
±11.5MPa
±23.1MPa
±34.6MPa
Displacement
±6,430nm
±12,900nm
±19,300nm
Von Mises Stress
±5.28MPa
±10.6MPa
±15.8MPa
Displacement
±11,900nm
±23,800nm
±35,700nm
Von Mises Stress
±0.102MPa
±.204MPa
±0.306MPa
Displacement
±17.9nm
±35.8nm
±53.7nm
+Y
-Y
+Z
-Z
72
FUTURE PLANS
 Rerun simulations using latest iteration of chassis
 Run physical random vibration tests
73
Mechanisms: “Tuna Can”
74
ANTENNA HOLDER OVERVIEW
REQ ID
STRC‐02



Requirement
Parent(s)
ELFIN shall be capable of constraining all deployables SYS‐25
Verification Method
I: inspection
Two antennas, four elements
Rolled up and secured with fishing lines, which two resistors will
burn through to release them
Utilizes the 3U+extra volume on the –X panel
75
TUNA CAN DESIGN
AND
MICD
- Tuna can will be secured by 4
brass ½’’ 2-56 brass bolts with
hex nuts on the bottom side
- 4 holes feeding over 4 10 ohm
resistors
- Two of the resistors will serve as
redundancy
- 4 holes for antennas connections
76
MATERIAL SELECTION
Delrin vs. PEEK vs. 3-D Printed Materials




Mechanical/Thermal Properties
Costs/Machinability
UV Radiation Resistance/Outgassing
Corrosion Resistance against Atomic Oxygen
Name
Yield
Strength
(MPa)
Density
(g/cc)
Outgassing Rate
(%TML)
Delrin
NC010
G100
73
1.42
0.34
PEEK
(unfilled)
90 –
140
1.23 –
1.65
0.2
Windform
XT 2.0
84
1.10
0.53
77
MATERIAL SELECTION
Nylon Monofilament vs. Spectra Line
Spectra Line has a smaller index of elongation
Resistance to UV Light
Nylon
Monofilament
Spectra Line
(S900)
Density (g/cc)
1.14
0.97
Melting Point
220 °C
147 °C
Elongation (%)
25
3.9
UV Resistance
Low
Very High
Tenacity (gpd)
6
25
78
TESTING OVERVIEW
REQ ID
STRC‐10
Requirement
All antennas shall be capable of deploying while ELFIN is tumbling.
Parent(s)
SYS‐25
Verification Method
Thorough testing of all deployable antennas to ensure a minimum 99.9% success rate.
- Utilize arduino code with burn time of 9 seconds
- Investigating the effect of variance in temperature with success of
deployment
- Each of the permutations listed below will be repeated 3-5 times
1.
2.
3.
4.
5.
6.
7.
8.
Deploy at room temperature
Deploy cold
Long term hot deploy in hot
Long term hot deploy in cold
Long term cold deploy in hot
Long term cold deploy cold
Vacuum
Vibe and deploy
79
TESTING PROCEDURE
1. Stow antennas using fishing
line running over the
resistor.
2. Hook up the arduino-power
source to resistor.
3. Open and initialize the burn
code.
4. Set voltage to 5.4V and
burn time to 9 seconds.
5. Repeat in desired
environmental condition
Test Apparatus Deployed State
80
Mechanisms: Stacer
81
STACER OVERVIEW
Stowed State
•
•
Deployed State
Custom design provided by Kaleva Engineering systems
Flight heritage: Using identical stacer from ELFIN-L
82
STACER FUNCTIONALITY
REQ ID
Requirement
Parent(s)
The spacecraft shall be capable of deploying SYS‐25
STRC‐13
the stacer
•
•
•
•
•
Verification Method
component testing
Magnetometer is situated on
75cm boom
Boom consists of 3 helical BeCu
elements
Gore cable runs from
instrument to the electronic
board
Flywheel braking mechanism
SMAR actuation mechanism
83
STACER-MICD
•
•
+Z Stacer bracket
Stacer Chute
•
Stacer is situated in
middle U
Considered a main
structural element
(replaces the need for the
four cross braces
originating on the Boeing
tensor chassis design
Secured to chassis
through 3 Delrin brackets
and four fasteners on the
stacer chute
84
POWER - MECHANISMS
REQ ID
Requirement
Parent(s)
The Structures subsystem shall not exceed the power SYS‐22
STRC‐19
allocated in the ELFIN system power budget
Verification Method
Verification Procedure
T/A: Measured power consumption data during deployment tests
Power Budget
PowerBudget‐##‐B.xlsx
Current best estimates (CBEs) of deployment power: Supply voltages:
Stacer: +9V
VHF antenna: +9 V
UHF antenna: +9 V
Currents:
1250 mA
667 mA
667 mA
Power:
11.25 W
6.0 W
6.0 W
1563 mA
834 mA
834 mA
14.1 W
7.5 W
7.5 W
Margin: 25 %
CBE + Margin:
Stacer:
VHF antenna:
UHF antenna:
+9V
+9 V
+9 V
85
Harnessing
86
HARNESSING OVERVIEW
Objectives:
- List and document all the cables in the spacecraft, including the
following information (SYS-List_of_Cables-04)
- Cable types
- Connector types
- Cable Routes
- Pin outs
- drain locations
- Map out the connector locations in the avionics stack for the
SBPCB1 and SBPCB 2, LETC 1 and LETC 2, and BETC 1
- Test bend radius’s of cables and make appropriate design
changes if needed
87
HARNESSING SCHEMATIC
88
PRELIMINARY RESULTS
Completed Tasks:
-Connector locations in the avionics stack have been mapped
out, except for the FPCB
-Complete list of cables have been mapped out
-A first attempt has been made for harnessing, focusing on the
cables that cross over the stacer
Design Changes from first Harnessing:
-rotation of avionics unit in ZY plane
-divots in sides of battery mounts leading into terminals
-alteration in stacer demating process
-rotation of coax connectors on He-82 Radios
89
PROBLEMS
AND
FUTURE TASKS
Problems
- Spacing issues in the Avionics Unit
- Flexi-cables vs. additional mezzanines
- Battery formation may needs to be altered
- 14 shielded twisted pair cable from LETC 1 to SIPS and IDPU
- Stacer tie downs interfering with the demating process
90
Facilities
91
IN-HOUSE FACILITIES
3D printer
 Used for assembly of 3D model
 Have access to PLA and ABS
spools
Proto-lab
 In-house machining for
aluminum components, such as
the chassis and the battery
mounts.
Thermal Vacuum Chamber
 Can be used to test various
temperature environmental
conditions for antenna
deployment
92
Safety
93
SAFETY
 ESD
 All Flight Hardware
 Preventative Steps: ESD Training Sessions
 Structural
 Protective measures for 3D printer and machine
shop: machine shop training
 Performance Assurance: Staff members
 Documents will be created by students and staff
94
Future Tasks
95
FUTURE TASKS SUMMARY
Future Tasks
▪ Standardize method of stowing antennas
▪ Fully map out EMI shield
▪ Complete harnessing mock-up, documenting all cables
including bend radius
▪ Conduct antenna deployment tests with thermal vacuum
▪ Complete more accurate static simulations
96
ACKNOWLEDGEMENTS
Thank you to all of our sponsors, stakeholders,
and contributors
Shaun Murphy @ Northrop Grumman
Katharine Gamble @ UT Austin
Jim White WD0E @ Colorado Satellite Services
Mark Spencer WA8SME @ ARRL
Tony Monteiro AA2TX & Bob Davis KF4KSS @ AMSAT-NA
Mechanical Preliminary Design Review
97
Additional Slides
98
Complete Harnessing
Schematic
99
AVIONICS UNIT OVERVIEW
100
BATTERY HOLDER REDESIGN
Battery Mount Drawing View
Battery Mount Isometric View
101