Task 148: EP02 On-Screen Data Extraction

Status: DONE

Motivation

Extending video frame analysis from EP01 (Task 146) to EP02.

EP02 covers Jupiter escape → Saturn/Enceladus arrival with a 455-day ballistic transfer.

On-screen displays may reveal navigation parameters for this interplanetary leg.

Key Timestamps

• 00:53 — 冷却系圧力0.04MPa低下（EVA点検シーン）
• 01:46 — 相対速度増加傾向、3時間後に最近接を外れる（木星・イオ近傍）
• 06:58 — 木星離脱航路（イオ・トーラス外縁スカート付近）、追手到達まで13時間
• 09:07 — 高度50 RJ、木星基準速度10.3 km/s（磁気圏縁ゲート）
• 13:27 — エンケラドゥス・リレー到着（国際連合・火星自治連邦保護領 / 土星圏）
• 16:18 — 外縁軌道投入推進シークエンス開始（点火ウィンドウまで5時間）
• 16:37 — NAVIGATION OVERVIEW — COIAS軌道交差警報、相対速度-0.12 km/s ★最重要
• 17:18 — 恒星掩蔽による大型船検知
• 17:28 — 大型船の待ち伏せ戦術推定（航法灯・トランスポンダOFF、相対速度≈0）

Key Findings

Navigation Display (16:37) — Most Data-Rich Frame

• NAVIGATION OVERVIEW display with Saturn-centric orbital diagram
• System: MARS PORT AUTHORITY (火星港湾公社)
• Ship ID: MTS-9907/EXT-P17 (ケストレルの船籍番号、初めて判明)
• Alert system: COIAS (ORBITAL CROSS ALERT)
• Relative velocity: -0.12 km/s (120 m/s) — approaching
• "OVERS BURN" label — overshoot correction burn (EP01の PERIJOVE OVERSHOT CORRECTION に対応)
• Orbital diagram shows: SATURN center, CELADUS ORBIT, S2-ENCELADUS, INTERSECTION point
• Unknown vessel ID: MPA-MC-SCV-02814 (50万t級大型船)

Jupiter Departure Parameters (09:07-09:11)

• Location: 木星磁気圏縁ゲート (magnetosphere edge gate)
• Altitude: 50 RJ (Jupiter radii)
• Jupiter-relative velocity: 10.3 km/s
• Trajectory: 扇状面の中心線に同調 (synchronized with Io torus fan plane center line)
• Thrust: trim only (no main engine)
• V∞ from Jupiter ≈ 5.93 km/s (computed: sqrt(10.3² - 8.42²))

Location Labels (Scene Setting Captions)

Three distinct location labels:

1. 木星離脱航路 (イオ・トーラス外縁スカート付近) / 木星港湾公社 / 木星圏
2. 木星離脱航路 (木星磁気圏縁ゲート) / 木星港湾公社 / 木星圏
3. エンケラドゥス・リレー / 国際連合・火星自治連邦保護領 / 土星圏

Other Technical Data

• Cooling pressure drop: 0.04 MPa (outer secondary cooling line)
• Pursuit ships: Earth/Mars ships, 13 hours ETA
• Large ship detection: stellar occultation (background star monitoring)
• Large ship tactics: nav lights OFF, transponder OFF, near-zero relative velocity

Comparison with EP01

EP01 had a richer navigation HUD (V∞, ΔV values, 3-phase burn sequence, azimuth).

EP02's NAVIGATION OVERVIEW focuses on collision avoidance and is less parameter-dense.

However, EP02 uniquely reveals:

• Kestrel's ship registration number (MTS-9907/EXT-P17)
• Mars Port Authority operating system
• COIAS alert system
• Large ship vessel ID (MPA-MC-SCV-02814)
• Jurisdiction labels for different space regions

Artifacts

• reports/data/episodes/ep02_onscreen_data.json: Structured on-screen data (19 frames)
• ts/src/extract-frames.py: Updated with EP02 keyframe timestamps
• raw_data/frames/ep02/: Extracted frame images (gitignored)

Dependencies

• Task 146 (frame extraction pipeline) — DONE