Pass first. Then weigh in.
Structural qualification is pass/fail. Among the structures that pass every requirement, the lowest total assembled mass wins.
POE Unit 0 • Lesson 0.10
CubeSat Lightweight Structure Competition
Focus question: Which engineering choices produced the lightest CubeSat structure that can still pass every qualification requirement?
Challenge Rules
CubeSat Lightweight Structure Challenge
Every team works inside the same architecture and material limits. Your engineering advantage comes from how efficiently you use them.
- Maximum assembled envelope: 4 in × 4 in × 4 in, including hardware.
- Top and bottom: laser cut from the team’s single 4 in × 12 in × 1/8 in acrylic sheet.
- Sides: remain open; no side panels.
- Primary frame: 3D printed using the same teacher-selected filament material for every team.
- Assembly: M3 screws for all primary structural connections; structural glue is not permitted.
- Serviceability: the structure must be able to be disassembled and reassembled with normal hand tools.
- Competition: the lightest structure that passes every qualification requirement wins.
Lesson Targets
What You Will Be Able to Do
I can complete a final qualification check, interpret competition data, and defend the engineering decisions that shaped my team’s structure.
Final CubeSat + qualification record + official mass + short engineering design review
The structure passes every required check before weigh-in, and the team can connect its final mass and performance to specific design decisions.
Activity Flow
How Today Advances the CubeSat
1. Qualify the structure
Complete dimensional, construction, and standardized structural checks.
2. Official weigh-in
Only qualifying structures receive an official competition mass.
3. Defend the design
Connect final performance to geometry, material removal, print settings, and assembly decisions.
Qualification Sequence
Pass Every Gate Before the Scale
Qualification determines whether a structure is eligible. Mass ranks only the structures that qualify.
| Gate | Requirement | Result |
|---|---|---|
| 1. Envelope | Entire assembled structure fits within 4 in × 4 in × 4 in. | PASS / FAIL |
| 2. Construction | Laser-cut 1/8 in acrylic top/base, open sides, 3D-printed frame, M3 structural assembly, no structural adhesive. | PASS / FAIL |
| 3. Structural Load | Support a standardized 10 lb vertical load for 30 seconds using the teacher-provided load plate without fracture, joint separation, or visible permanent deformation. | PASS / FAIL |
| 4. Assembly Integrity | M3 joints remain secure and the structure remains serviceable after the load test. | PASS / FAIL |
| 5. Weigh-In | Qualifying structure is measured to the nearest 0.1 g. | Official Mass |
Lowest Qualified Mass
The lightest CubeSat structure that passes all four qualification gates wins.
Structural Efficiency
If official masses are within 1.0 g, lower measured deflection during the same load test wins. If still tied, greater usable interior volume wins.
Project Milestone
Today’s Required Deliverable
Final Competition Record & Design Review
- Final assembled mass, including acrylic, printed frame, M3 hardware, inserts/nuts/washers, and all permanent components.
- Pass/fail results for every qualification requirement.
- Final print settings and estimated filament use.
- One design decision that reduced mass.
- One design decision that supported structural strength.
- One change the team would make if a second version were allowed.
Engineering Decision
Document the Reasoning
What did your team decide today?
What measurements, requirements, comparisons, calculations, or manufacturing information support that decision?
Why does that evidence make the decision appropriate for a lightweight structure that still has to qualify?
Resources
Lesson Resources
CubeSat Unit 0 Overview
Review the complete challenge sequence, project rules, deliverables, and competition objective.
Principles of Engineering
Return to the POE hub for units, course resources, and certifications.