Task 164: Cross-Episode Heliocentric Velocity Profile Chart

Status: DONE

Motivation

The cross-episode summary page has mass timeline and margin charts, but lacks a heliocentric velocity profile showing the ship's speed throughout the entire 479-day mission. This is a fundamental visualization that shows:

• Brachistochrone acceleration/deceleration phases (EP01, EP03, EP05)
• Ballistic coast velocity during EP02's 455-day Jupiter→Saturn transit
• Jupiter flyby velocity boost in EP05
• Maximum and minimum speeds during the mission

This makes the mission trajectory dynamics intuitively understandable.

Approach

1. Compile velocity data from each episode's calculations:

- EP01: Mars departure → Jupiter arrival (brachistochrone ΔV + orbital speeds)

- EP02: Jupiter escape → ballistic → Saturn capture

- EP03: Saturn → Uranus (brachistochrone)

- EP04-05: Uranus → Earth (composite route with Jupiter flyby)

1. Create a time-series chart with mission elapsed time (days) on X-axis and heliocentric speed (km/s) on Y-axis
2. Add to the "航路の連続性" section alongside the existing full-route orbital diagram

Data Sources

• EP calculations: reports/data/calculations/ep0X_calculations.json
• Cross-episode mass timeline: existing propellant-mass-timeline chart for time anchors
• Orbital mechanics: vis-viva equation for heliocentric velocities at each planet

Dependencies

• Task 163 (DONE)