CubeSTEM Digital Twin · Track 3
Track 3 — Power / Thermal / Budgets
A four-session mini-course: power budgeting with duty cycles → sunlight/eclipse energy balance → simplified thermal hot/cold reasoning → mass/volume/resource trade-offs with explicit margin.
Local-only mini-course: no account, no submissions, no gradebook. Teaching-grade estimates — not certified power, thermal, or mass analysis, not battery safety certification, not remote hardware.
What this mini-course teaches
Learn how power, energy, thermal limits, and finite mass/volume constrain what a CubeSat mission can do — with honest teaching-grade models.
Mini-course flow
Four sessions, one budgets story
Follow the sequence below to move from power budgeting → sunlight/eclipse energy balance → simplified thermal hot/cold screening → mass/volume/resource trade-offs. Evidence and self-checks are local-only — copy, export, or screenshot if you want to share.
Recommended pacing: treat each activity as one session. Use the “Next” link inside the activity pages to continue in order.
Session 1
Power Budget Basics
Time estimate: 25–35 min
Learning goal: Student can compare average and peak bus power, explain duty-cycle effects, and read a simple margin result (safe / warning / overloaded).
Expected evidence (local)
- Selected mission preset and load / duty settings
- Average power, peak power, and generation vs consumption summary
- Margin status and one-sentence largest consumer or driver
Session 2
Day / Night Energy Balance
Time estimate: 25–35 min
Learning goal: Student can relate sunlight vs eclipse time, average load, and stored energy to a remaining-reserve warning (teaching estimate).
Expected evidence (local)
- Sun / eclipse / orbit settings and average load
- Energy generated in sun and energy drawn in eclipse (teaching Wh estimate)
- Battery remaining or reserve status and one mitigation if low
Session 3
Thermal Hot / Cold Case
Time estimate: 20–30 min
Learning goal: Student can explain when a simplified model flags hot or cold risk and what an engineer would check first (teaching-grade).
Expected evidence (local)
- Selected environment and duty/heater settings
- Hot/cold/marginal risk flag and component limit focus
- First engineering check statement
Session 4
Mass / Volume / Resource Trade-off
Time estimate: 25–35 min
Learning goal: Student can allocate limited resources, interpret warnings, and justify a chosen strategy with evidence (teaching exercise).
Expected evidence (local)
- Allocation table and remaining budget
- Warnings triggered and accepted trade-off
- Selected strategy and one-sentence justification
Extension / path-only items
No interactive pageThese Track 3 path entries stay honest path-only items. They are not part of the four-session mini-course and do not have dedicated interactive routes — use the curriculum map and Mission Design Lab for related teaching estimates.
- Solar Power Generation — Understand how solar panels on a CubeSat generate power and what affects solar input (path item — interactive page planned in Track 3 closeout).
- Data Budget and Downlink Limit — Understand how data generation, storage, and downlink rate create a data budget constraint (path item — interactive page planned in Track 3 closeout).
- Risk Flags and Engineering Decisions — Interpret risk flags across all budgets and make a justified engineering decision (path item — interactive page planned in Track 3 closeout).
Teacher plan
Track 3 — Power / Thermal / Budgets
Focus on resource realism after Track 2 mission choices. Keep language humble: teaching-grade estimates, not certified power, thermal, mass, or battery-safety analysis. Local-only — no submissions, no gradebook, no teacher visibility unless artifacts are shared manually.
45-minute essentials
45 min
- 5 min boundaries + Track 2 recap (mission objective → budgets).
- 15 min Power Budget Basics — average vs peak with duty cycles.
- 15 min Day / Night Energy Balance — eclipse stress.
- 10 min reflection + evidence copy/export per team.
90-minute workshop
90 min
- 20 min Sessions 1–2 + compare team results.
- 25 min Thermal Hot / Cold — debate “first check” language.
- 30 min Resource Trade-off design review with explicit margin.
- 15 min cross-track tie-back to Track 2 mission objectives.
Half-day studio
3+ hrs
- Run all four core sessions with facilitated pivots between teams.
- Add a Mission Design Lab glance at qualitative budget labels.
- Portfolio: one evidence artifact per team per session.
- Wrap with the “After Track 3” bridge to Track 4 / curriculum.
Misconceptions bank
- Peak power and average power are not the same when loads are duty-cycled.
- More solar panel area is not “free” — it costs mass, volume, and sometimes pointing complexity.
- Eclipse matters even when sunlight charging looks strong — energy is power × time.
- Thermal risk can be hot or cold; vacuum changes cooling paths.
- Margin is part of engineering, not wasted resource.
- Browser labs are teaching-grade — not flight-grade power/thermal certification.
After Track 3
Bridge into Communication / Ground Link (Track 4) next — its four-session yardstick mini-course ships now. The Curriculum Map remains a safe fallback. Keep evidence local — no submissions or gradebook.
Student path
What to do, step by step
This is a guided path, not a submission system. Your evidence and self-check stay in your browser unless you copy/export or screenshot it to share manually.
Tip: after each session, open the Evidence panel and copy/export your artifact (text or JSON) before moving on.
Step 1
Power Budget Basics
Time estimate: 25–35 min
- Pick a mission preset and set load chips, payload/radio duty cycles, and a solar generation preset.
- Read average power, peak power, and the generation-vs-consumption summary.
- Note the margin status (safe / warning / overloaded) and identify the largest consumer.
- Capture evidence: settings + average/peak/margin + one-sentence largest-driver note.
Step 2
Day / Night Energy Balance
Time estimate: 25–35 min
- Set sunlight vs eclipse minutes, battery capacity, average load, and payload duty.
- Read teaching Wh estimates for energy generated in sun vs energy drawn in eclipse.
- Inspect battery remaining / reserve status and propose one mitigation if low.
- Capture evidence: settings + Wh estimates + reserve status + mitigation.
Step 3
Thermal Hot / Cold Case
Time estimate: 20–30 min
- Pick sun / eclipse / mixed environment and set payload + radio duty cycles.
- Toggle the survival heater and read the hot/cold/marginal risk flag.
- Write one engineering “first check” for the flagged component limit.
- Capture evidence: environment + duty/heater + risk flag + first-check sentence.
Step 4
Mass / Volume / Resource Trade-off
Time estimate: 25–35 min
- Spend a fixed point budget across payload, battery, structure, radio, ADCS, thermal, and margin.
- Inspect warnings and pick a design strategy that accepts an explicit trade-off.
- Justify which subsystem you starved on purpose and why.
- Capture evidence: allocation + warnings + strategy + reflection sentence.
After Track 3
Continue into Track 4 — Communication / Ground Link. Its four-session yardstick mini-course is live, with line-of-sight, data rate × contact time, link margin trade-off, and command/telemetry flow labs. Track 3 extension items (solar generation, data budget, risk flags) remain honest path-only entries — explore them on the curriculum map only, no interactive page yet.
Evidence checklist
What to capture (local-only)
Evidence artifacts are local-only. There is no submission or teacher visibility workflow — copy/export (text or JSON) or screenshot to share manually.
Classroom routine tip: after each session, copy/export one artifact per team and paste into a shared doc.
Power Budget Basics
⏱ 25–35 min
- Selected mission preset and load / duty settings
- Average power, peak power, and generation vs consumption summary
- Margin status and one-sentence largest consumer or driver
- Local self-check summary and copied evidence text
Reflection prompt: Why is average power not the same as peak power, and why do teams still plan for peak?
Day / Night Energy Balance
⏱ 25–35 min
- Sun / eclipse / orbit settings and average load
- Energy generated in sun and energy drawn in eclipse (teaching Wh estimate)
- Battery remaining or reserve status and one mitigation if low
- Local self-check summary and copied evidence text
Reflection prompt: Why can a mission look power-positive in sunlight but still fail in eclipse?
Thermal Hot / Cold Case
⏱ 20–30 min
- Selected environment and duty/heater settings
- Hot/cold/marginal risk flag and component limit focus
- First engineering check statement
- Local self-check summary and copied evidence text
Reflection prompt: Why can both overheating and overcooling be mission risks for the same spacecraft?
Mass / Volume / Resource Trade-off
⏱ 25–35 min
- Allocation table and remaining budget
- Warnings triggered and accepted trade-off
- Selected strategy and one-sentence justification
- Local self-check summary and copied evidence text
Reflection prompt: Why can’t payload, battery, radio, and engineering margin all be maximized at once?
Boundary reminder: teaching-grade power, thermal, and resource models — not certified analysis, not battery safety certification, no remote hardware. Evidence is local-only.
Assessment map
Self-check prompts (not a grade)
Local-only practice — no gradebook, no teacher visibility unless learners share artifacts manually. Use the prompts below as discussion starters during reviews and team debriefs.
Power Budget Basics
Open →Prompt: Why is average power not the same as peak power, and why do teams still plan for peak?
Common misconceptions
- “Average power equals peak power.” (Duty cycles drop the average; peaks still size hardware.)
- “More solar panel area is always free.” (Mass, volume, pointing, and thermal still bind.)
Day / Night Energy Balance
Open →Prompt: Why can a mission look power-positive in sunlight but still fail in eclipse?
Common misconceptions
- “Strong sunlight charging fixes everything.” (Eclipse still drains stored energy if load is high.)
- “Battery stories here are certification claims.” (This lab is a teaching estimator — not safety certification.)
Thermal Hot / Cold Case
Open →Prompt: Why can both overheating and overcooling be mission risks for the same spacecraft?
Common misconceptions
- “Thermal risk is only overheating.” (Cold cases and survival heating matter.)
- “This chart replaces thermal analysis.” (Flight programs use deeper models + test.)
Mass / Volume / Resource Trade-off
Open →Prompt: Why can’t payload, battery, radio, and engineering margin all be maximized at once?
Common misconceptions
- “Margin is wasted mass.” (Margin buys resilience against unknowns.)
- “We can max payload, battery, radio, and margin together.” (Fixed budgets force trade-offs.)
Teaching-grade boundary
Local-only teaching model — not flight-grade EPS, thermal, or mass analysis; no battery certification claims; evidence is not submitted anywhere and is not a grade.
No flight-certified power, thermal, or mass analysis. No battery safety certification. No remote hardware control. Track 4 — Communication / Ground Link — now ships as the next mini-course; the Curriculum Map remains a safe fallback.
Full Track 3 path (4 core + 3 extension/path-only)
The four core activities ship as interactive sessions. The three extension items remain honest path-only entries — no dedicated activity route — and stay listed for curriculum continuity.
- Power Budget BasicsCore — Estimate average and peak power from subsystem loads and duty cycles; compare generation vs consumption with engineering margin.
- Day / Night Energy BalanceCore — Compare sunlight charging, eclipse energy draw, and battery reserve using a simple energy-balance teaching model.
- Thermal Hot / Cold CaseCore — Use a simplified hot/cold case model: environment, internal heat, and limits — without claiming flight thermal analysis.
- Mass / Volume / Resource Trade-offCore — Allocate finite mass/volume/power budget points across subsystems; pick a strategy and accept an explicit trade-off.
- Solar Power GenerationExtension / path-only — Understand how solar panels on a CubeSat generate power and what affects solar input (path item — interactive page planned in Track 3 closeout).
- Data Budget and Downlink LimitExtension / path-only — Understand how data generation, storage, and downlink rate create a data budget constraint (path item — interactive page planned in Track 3 closeout).
- Risk Flags and Engineering DecisionsExtension / path-only — Interpret risk flags across all budgets and make a justified engineering decision (path item — interactive page planned in Track 3 closeout).
Next step after Track 3
Communication / Ground Link — or curriculum map
Track 4 — Communication / Ground Link — ships as the next four-session yardstick mini-course (line of sight, data rate × contact time, link margin trade-off, command/telemetry flow). The Curriculum Map remains a safe fallback.