Mission ATLAS #06 — Asteroid Deflection: The 31.5 Rule

MISSION ATLAS #06 · NEO DEFENSE COMMAND — RETROFIT v3

☄️ ASTEROID DEFLECTION: The 31.5 Rule

Planetary Defense DeskDART 2022 · first real deflectionONE relationship: d = Δv · t

🎯 Learning target

Master ONE relationship — the drift rule of planetary defense:
d [km] = 31.5 · Δv [mm/s] · t [yr]
Forward, inverse, and under a red-alert clock.

⚠️ Misconception to break

"You need a huge blast at the last second." Backwards: you need a whisper of a push, years early. Panic has no time to multiply; physics does.

🧪 Model & assumptions (stated honestly)

Straight-line drift model, first order — real along-track burns gain EXTRA via orbital mechanics · 1 yr ≈ 3.15×10⁷ s (exact 3.156×10⁷) so 1 mm/s → 31.5 km/yr · Δv delivered instantly at burn (impactor momentum, β-effects = engineering flavour, not graded) · gravitational keyholes are real (Apophis 2029) — modelled here as a target corridor · all runs show honest TIME ×N with dual clocks.

Difficulty generous tolerances

📐 Key formulas (given)

drift: d = 31.5 · Δv · t units: d[km] · Δv[mm/s] · t[years] inverse: Δv = d / (31.5 · t) why 31.5: 1 mm/s × 3.15×10⁷ s = 31.5 km per year

🕹 Curriculum — 4 watches

1️⃣ Panic vs Physics · Watch — play the arcade, lose; compute, win
2️⃣ Track · Predict — Δv & t given; your miss d arms the launch
3️⃣ Corridor · Inverse — corridor wants d; you set Δv
4️⃣ Red Alert · Crisis — 90 s, pick the interceptor, save Earth
Bronze+ opens the next watch. Scenarios re-roll every retry.

Controls

Space thrust/launch · A/D/←→ thrust (manual) · Enter commit · P pause · R reset · H hint. Wrong submissions −2 pts.

🏅 How scoring works

Every stage: answer the reasoning question, then compute and commit a number. Your medal is set by accuracy — 🥇 under 5% · 🥈 under 10% · 🥉 under 20% error — and a Bronze or better unlocks the next stage. A wrong answer costs −2 points (−1 on Easy, and your first reasoning slip on each question is free on Easy). A hint costs −3/−4/−5. Fewer tries and higher accuracy mean a higher score — so it always pays to calculate, not guess.