Appendix E1: Iteration Designs

Details for previous iterations and material comparison can be found in the Interim Report.

First Iteration: All components on the same side of PCB, covered by 1 shield. Problems: Not enough space for all components.

Fig E1-1. First Iteration

Second Iteration: Shielded and unshielded components on opposite sides of the same PCB. Problems: Close proximity of high and low voltage components.

Fig E1-2. Second Iteration

Third Iteration: PCBs for high and low voltage components. Shielded components on the inside of middle shielding. Problem: Thin structures (on the outside of pin stacks) which were vulnerable to vibrations and stress.

Fig E1-3. Third Iteration

Final Iteration: Optimised design from 3rd iteration.

Appendix E2: CAD Models

Fig E2-1. Top View

Fig E2-2. Bottom View

Fig E2-3. Side View

Fig E2-4. Isometric View

Fig E2-5. Isometric View without Central Shielding

Fig E2-6. Inner Side of High Voltage PCB

Fig E2-7. Inner Side of Low Voltage PCB

Appendix E3: Material Choice Summary

Details of the materials can be found in the Interim Report.

Material	Pros	Cons
PEEK	Very available Light compared to metals at 1.32g/cm^3 (Curbell plastics, n.d.) Radiation Resistant (Ensinger, n.d.)	Does not have strong shielding properties without high Z materials added as composite. (Khozemy et al., 2022)
PEEK infused with heavy atoms	Strong shielding properties. (Khozemy et al., 2022)	Unavailable and expensive. (Khozemy et al., 2022)
Aluminium 6061	Very available	Only shields alpha and beta particles. (IMS Team, n.d.)
Concrete	Strong shielding properties. (IMS Team, n.d.) (Onaizi et al, 2024)	Heavy and brittle (Onaizi et al, 2024)
Lead	Strong shielding properties. (IMS Team, n.d.)	Environmental unfriendly (Sampson, n.d.) Heavy

Table E3-1. Material Comparison

Appendix E4: Radiation Experiment Data

Fig E4-1. GM Counters

Fig E4-2. GM Tube Specs

Background radiation can fluctuate from 20 to 100 CPM. (Link)

Each reading is 30 minutes. We first check whether the two counters are calibrated. A total of 7 readings are taken, with both GM Counters left outside.

No.	Counter A	Counter B
1	2598	2613
2	2612	2542
3	2586	2576
4	2624	2710
5	2655	2453
6	2587	2573
7	2534	2474
Avg	2599.43	2563.00
CPM	86.64761905	85.43333333

Table E4-1. GM Counter Readings

The counters are calibrated and have very close values.

Fig E4-3. GM Counters and Aluminium Boxes

Next we put Counter A inside the box and Counter B outside the box and take the reading. We swap the two counters and take the readings again to average out any errors from their differences. Then we repeat for different thicknesses.

Raw Data	Counter A	Counter B		Counter A	Counter B
Thickness	Inside Box (1)	Inside Box (2)	Inside Box (Average)	Outside Box (1)	Outside Box (2)	Outside Box (Average)
0mm	2598	2576	2587	2613	2586	2599.5
2mm	2480	2428	2454	2496	2613	2554.5
4mm	2247	2448	2347.5	2526	2579	2552.5
6mm	2294	2262	2278	2596	2635	2615.5
8mm	2258	2247	2252.5	2600	2548	2574
10mm	2093	2079	2086	2557	2629	2593

Table E4-2. Counter Data

We collect more data.

Raw Data	Counter A	Counter B		Counter A	Counter B
Thickness	Inside Box (1)	Inside Box (2)	Inside Box (Average)	Outside Box (1)	Outside Box (2)	Outside Box (Average)
0mm	2547	2554	2550.5	2534	2572	2553
2mm	2467	2429	2448	2578	2497	2537.5
4mm	2389	2401	2395	2562	2554	2558
6mm	2212	2365	2288.5	2510	2520	2515
8mm	2176	2260	2218	2496	2495	2495.5
10mm	2116	2230	2173	2470	2396	2433

Table E4-3. Counter Data

We tabulate the data below.

Thickness (mm)	Inside Box	CPM	Outside Box	CPM	Absolute Difference (CPM)	Percentage Drop
0	2573.7	85.79	2576.3	85.88	0.09	0.10%
2	2458.3	81.94	2546.0	84.87	2.92	3.44%
4	2361.3	78.71	2555.3	85.18	6.46	7.59%
6	2256.0	75.20	2565.3	85.51	10.31	12.06%
8	2227.0	74.23	2534.8	84.49	10.26	12.14%
10	2129.5	70.98	2513.0	83.77	12.78	15.26%

Table E4-4. Counter Data Analysis

Graph is plotted. It plateaus after 6mm.

Fig E4-4. Counter Data Analysis

Appendix E5: Bill of Materials and Mass Budget

Item	Material	Manufacturing Method	Mass (g)	Number of Counts	Total Mass (g)
Top Shielding	Aluminum 6061	CNC	47.5	1	47.5
Bottom Shielding	Aluminum 6061	CNC	54.5	1	54.5
Middle Shielding	Aluminum 6061	CNC	138.0	1	138.0
HV PCB (Soldered)	FR4	Bought	56.0	1	56.0
LV PCB (Soldered)	FR4	Bought	60.0	1	60.0
Bolts	Stainless Steel	Bought	3.0	4	12.0
Spacer	Stainless Steel	Bought	0.5	10	5.0
Pin Stacks	Plastic and Copper	Bought	6.5	2	13.0
Thermal Interface Material	Thermal Interface Material	Bought	-	-	-
Total					386.0

Table E5-1. Bill of Materials

The precision of the scale was 0.5 grams. The mass of the full module is 388.5g.

Fig E5-1. Weighing

Appendix E6: Physical Parameters

Height: 48.0mm Length and Breadth: 96.39mm by 94.33mm

Fig E6-1 and E6-2. Physical Parameters

Centre of Gravity: X = 43.39mm Y = 48.03mm Z = -14.22mm

Fig E6-3 and E6-4. Centre of Gravity

Moment of Inertia (at CG):

Lxx = 387471.00	Lxy = 15000.87	Lxz = 16132.16
Lyx = 15000.87	Lyy = 397053.44	Lyz = 23131.01
Lzx = 16132.16	Lzy = 23131.01	Lzz = 648808.59

Table E6-1. Moment of Inertia

Fig E6-5. Moment of Inertia

Appendix E7: Jig Drawing

Fig E7-1. Jig CAD

Fig E7-2. Jig Drawing

Note: There was some mistake by the manufacturer. In this drawing, the central hole is missing and the M3 holes were mirrored. The mistakes were subsequently fixed.

Appendix E8: Test Profiles

Test profiles are taken from SpaceX.

Sine Profile: (1.25x MPE)

Axial

Fig E8-1. Sine Profile Axial

• Frequency range: 5 Hz to 100 Hz.
• Acceleration levels:
  • 5Hz: ±0.5g * 1.25 = ±0.625g.
  • 20Hz: ±0.8g * 1.25 = ±1.00g
  • Peaks at ±0.9g * 1.25 = ±1.125g at 100 Hz.

No.	Description	Time
1	Start at 5Hz and 0.625g amplitude	-
2	Increase frequency from 5Hz to 20Hz at a rate of 2 oct/min, increase amplitude linearly from 0.625g to 1.00g at 20Hz	60 seconds
3	Increase frequency from 20Hz to 35Hz at a rate of 2 oct/min, amplitude remain at 1.00g	About 24.2 seconds
4	At the end of step 3, drop amplitude to 0.75g	-
5	Increase frequency from 35Hz to 75Hz at a rate of 2 oct/min, amplitude remain at 0.75g	About 33.0 seconds
6	Increase frequency from 75Hz to 85Hz at a rate of 2 oct/min, increase amplitude linearly from 0.75g to 1.125g at 85Hz	About 5.41 seconds
7	Increase frequency from 85Hz to 100Hz at a rate of 4 oct/min, amplitude remain at 1.125g	About 7.02 seconds
8	Repeat steps 1 to 7 one more time	About 130 seconds
9	End	-

Table E8-1. Sine Profile Axial

Total: about 260 seconds

Lateral

Fig E8-2. Sine Profile Lateral

• Frequency range: 5 Hz to 100 Hz
• Acceleration levels:
  • Constant ±0.5 * 1.25 = 0.625g between 5 Hz and 85 Hz.
  • Peaks at ±0.6 * 1.25 = 0.75g at 100 Hz.

No.	Description	Time
1	Start at 5Hz and 0.625g amplitude	-
2	Increase frequency from 5Hz to 85Hz at a rate of 2 oct/min, amplitude remain at 0.625g	About 120.6 seconds
3	Increase frequency from 85Hz to 100Hz at a rate of 2 oct/min, increase amplitude linearly from 0.625g to 0.75g at 85Hz	About 7.04 seconds
4	Repeat steps 1 to 3 one more time	About 130 seconds
5	Repeat steps 1 to 4 for the other lateral axis	About 260 seconds
6	End	-

Table E8-2. Sine Profile Lateral

Total: about 520 seconds

Random

Fig E8-3. Random Profile

All axes: Require +6dB (using Falcon)

Fig E8-4. Random Profile

No.	Description	Time
1	Vibrate from 20Hz to 100Hz with constant 0.0264 g^2/Hz	20s
2	Increase vibration from 100Hz with 0.0264 g^2/Hz to 300Hz with 0.04 g^2/Hz	20s
3	Vibrate from 300Hz to 700Hz with constant 0.04 g^2/Hz	20s
4	Increase vibration from 700Hz with 0.04 g^2/Hz to 800Hz with 0.12 g^2/Hz	20s
5	Vibrate from 800Hz to 925Hz with constant 0.12 g^2/Hz	20s
6	Decrease vibration from 925Hz with 0.12 g^2/Hz to 2000Hz with 0.03864 g^2/Hz	20s
7	Repeat steps 1 to 6 two more times	240s
8	Repeat steps 1 to 7 for the other two axes.	720s
9	End	-

Table E8-3. Random Profile

Total: about 1080 seconds

Thermal Cycling

No.	Description	Specification
1	Starting Temp	Room Temperature (assume 20°C)
2	High Peak Temperature	70°C
3	Low Peak Temperature	-25 and -30°C
4	Dwell Time*	4 hours
5	Ramp Cycles	10°C/minute
6	Cycles	2

Table E8-4. Thermal Cycling

No.	Description	Time
1	Room temperature (20°C) decrease to low peak temperature (-25°C)	4.5 minutes
2	Dwell at low peak temperature	4 hours
3	Low peak temperature (-25°C) increase to high peak temperature (70°C)	9.5 minutes
4	Dwell at high peak temperature	4 hours
5	High peak temperature (70°C) decrease to low peak temperature (-30°C)	10 minutes
6	Dwell at low peak temperature	4 hours
7	Low peak temperature (-30°C) increase to high peak temperature (70°C)	10 minutes
8	Dwell at high peak temperature	4 hours
9	High peak temperature (70°C) decrease to room temperature (20°C)	5 minutes
-	Total time	16 hours 39 minutes

Table E8-5. Thermal Cycling

Over Testing Procedures

No.	Test	Time
1	First Sine	About 15 minutes
2	First Random	About 20 minutes
3	Thermal	About 16 hours 41 minutes
4	Second Sine	About 15 minutes
5	Second Random	About 20 minutes

Table E8-6. Over Testing Procedures

Total: about 2 days

Appendix E9: Simulations

Static

Required Profile:

Fig E9-1. Static Profile

Axial: 1.25 * 8.5g

Fig E9-2. Static Profile Axial

Lateral: 1.25 * 3g

Fig E9-3. Static Profile Lateral

Fig E9-4. Static Profile Lateral

Sine Frequency

Find the resonance frequency

Fig E9-5. Sine Frequency

Fig E9-6. Sine Frequency

Thermal

Check for overheating

Fig E9-7. Thermal Simulation

Appendix E10: Test Results

Vibration results before thermal cycle: Link

Thermal cycle data: Link

Vibration results after thermal cycle: Link

Appendix E11: Usable area of PCB and Size of Components

Item	Dimensions (mm by mm)	Area (mm^2)	Usable Height (mm)
PCB	94.39 x 90.33	8526.25	-
Usable PCB Plate (Inner Side)	70.75 x 57.79	4088.64	20mm
Usable PCB Plate (Outer Side)	70.75 x 57.79	4088.64	3mm
Pin Stack	2.5 x 2.5	6.25	3mm

Table E11-1. PCB Size

Item	Dimensions (mm by mm)	Area (mm^2)	Height (mm)
Z-SOM	68.00 x 45.00	3060.00	3.00
AT-Mega	10.00 x 10.00	100.00	2.00
GM Tube	49.20 x 15.10	742.92	15.10
HV Converter	28.00 x 15.00	420.00	8.00

Table E11-2. Component Size