Task 008: Episode 2 Content Analysis

Status: DONE

Goal

Analyze orbital transfers depicted in Episode 2 of SOLAR LINE. Identify ΔV claims, evaluate plausibility, and generate report.

Depends on

• Task 002 (orbital mechanics library)
• Task 005 (report pipeline)
• Task 006 (Episode 1 analysis — as template)

Completed Work

1. Research: Identified Part 2 source (sm45407401 / YXZWJLKD7Oo), collected auto-generated subtitles
2. Orbital constants: Added Saturn, Uranus, Enceladus constants + escape/circular/hyperbolic velocity functions to orbital.ts
3. Analysis code: ep02-analysis.ts with 5 transfer analyses and 3 parameter explorations
4. Tests: 32 new tests, all passing (267/267 new tests pass; 3 pre-existing build test failures)
5. Report: ep02.json with 5 transfers, 3 explorations, 2 video cards, 8 dialogue quotes
6. Site build: ep-002.html generated successfully

Key Findings

• Jupiter escape at 50 RJ, 10.3 km/s: PLAUSIBLE — exceeds escape velocity (8.42 km/s), v_inf ≈ 5.93 km/s
• Solar system escape: Ship is on a solar-hyperbolic trajectory (v_helio ≈ 18.99 > v_esc_sun ≈ 18.46)
• Transit to Saturn: ~455 days on natural trajectory, passes Saturn orbit on the way out
• Saturn capture: Minimum ΔV ≈ 0.61 km/s (achievable even with trim-only thrust at 300t mass)
• "No correction burns" constraint: Margin to solar escape is only 0.53 km/s — very tight, making the constraint realistic
• 500,000t vessel encounter: Proximity ops at 0.12 km/s, 3 km — plausible intercept geometry

Codex Consultation

• Confirmed analysis approach covers key orbital mechanics aspects
• Suggested patched-conic chain (Jupiter SOI exit → heliocentric arc → Saturn SOI entry)
• Calculated v_esc at 50 RJ ≈ 8.42 km/s independently (matches our code)
• Recommended including Saturn capture ΔV analysis (implemented)

Files Modified/Created

• ts/src/orbital.ts — Added MU.SATURN, ORBIT_RADIUS.SATURN/URANUS, JUPITER_RADIUS, SATURN_RADIUS, ENCELADUS_ORBIT_RADIUS, escapeVelocity(), circularVelocity(), hyperbolicExcess()
• ts/src/ep02-analysis.ts — Full Episode 2 analysis module
• ts/src/ep02-analysis.test.ts — 32 tests for Episode 2 analysis
• ts/src/report-types.ts — Made computedDeltaV nullable (number | null)
• ts/src/templates.ts — Handle null computedDeltaV in transfer cards
• reports/data/episodes/ep02.json — Episode 2 report
• ts/reports/data/episodes/ep02_lines.json — Extracted dialogue (80 lines)