Ship Specs Window

Overview

A floating/draggable HUD window that displays ship design parameters, live performance metrics, and a schematic layout diagram. Accessible via Shift+U keyboard shortcut or the View menu.

Window Structure

The Ship Specs window is a standard floating window (floating-window class) with three tabs:

Tab	Content	Update Frequency
Specs	Static class parameters with bar gauges	On ship class change only
Performance	Live computed values	Every tick
Layout	SVG ship schematic	On ship class change only

Ship Class Configurations

Full parameter set per ship class, sourced from services/physics/src/config.py:

Parameter	Cargo Hauler	Fast Frigate	Unit
Dry Mass	100,000	8,000	kg
Fuel Capacity	60,000	15,000	kg
Max Thrust	400,000	600,000	N
Isp	15,000	20,000	s
Main Fuel Rate	2.72	3.06	kg/s
Wheel Capacity	40,000	5,000	N·m·s
RCS Linear Thrust	10,000	4,000	N
Max Wheel Torque	2,000	500	N·m
Max RCS Torque	20,000	8,000	N·m
RCS Fuel Rate Max	0.68	0.27	kg/s
RCS Linear Fuel Rate	0.34	0.14	kg/s
Controller ω_n	0.15	0.5	rad/s
Inertia Dry (X/Y/Z)	4M/4M/800k	40k/40k/15k	kg·m²
Inertia Full (X/Y/Z)	6.4M/6.4M/1.28M	80k/80k/30k	kg·m²

Specs Tab

Sections

1. Propulsion (color: #0af)
   • Thrust, Isp, Fuel Capacity, Dry Mass, Full Mass (dry + fuel), Max Delta-v
2. Attitude Control (color: #0c6)
   • Wheel Torque, Wheel Capacity, RCS Torque, RCS Linear Thrust, Controller ω_n
3. Inertia (Dry) (color: #c80)
   • Roll (X), Pitch (Y), Yaw (Z) moments of inertia

Bar Gauges

Each spec row displays:

• Label (left-aligned)
• Value with unit (right-aligned, monospace)
• Horizontal bar gauge: fill_width = value / max_across_all_classes

Bar fill color matches the section color.

Derived Values

• Full Mass = dry_mass + fuel_capacity
• Max Delta-v = Isp × g₀ × ln(full_mass / dry_mass)
  • g₀ = 9.80665 m/s²

Performance Tab

Sections

1. Propulsion
   • Thrust Level (%)
   • Current Thrust (N)
   • Acceleration (m/s²)
   • Mass Flow Rate (kg/s)
2. Mass
   • Current Mass (kg)
   • Fuel Remaining (kg + %)
   • Burn Time Remaining (s)
3. Performance
   • Delta-v Remaining (m/s)
   • TWR (using local gravity: μ/r²)
   • Max Acceleration empty (m/s²)
   • Max Acceleration full (m/s²)
4. Inertia (Current)
   • X, Y, Z moments interpolated by fuel fraction

Update Logic

Values computed each tick from current ship state data:

• fuel_fraction = fuel / fuel_capacity
• current_mass = dry_mass + fuel
• current_thrust = max_thrust × thrust_level
• acceleration = current_thrust / current_mass
• mass_flow = main_fuel_rate × thrust_level
• burn_time = fuel / mass_flow (if mass_flow > 0)
• delta_v = isp × g₀ × ln(current_mass / dry_mass)
• local_g = μ / r² (r = distance to reference body center)
• twr = acceleration / local_g
• current_inertia[i] = inertia_dry[i] + fuel_fraction × (inertia_full[i] - inertia_dry[i])

Layout Tab

SVG ship schematic with viewBox ~320×400.

Content

• Side view (upper half): Profile with hull outline, engine bell, RCS pod positions, fuel tank
• Top view (lower half): Plan view with hull outline, RCS positions, dimensional annotations
• Labels with leader lines using project palette colors
• Class-specific drawing functions: drawCargoHaulerLayout() / drawFastFrigateLayout()

Styling

• Labels: #6cf
• Dimensions: #888
• Hull outlines: #334 stroke
• Engine: #c60 fill
• RCS pods: #0c6 fill
• Fuel tanks: #06a fill

Settings Persistence

Key	Type	Default	Description
shipSpecs	boolean	false	Window visibility
shipSpecsActiveTab	string	'specs'	Active tab name

Keyboard Shortcut

• Shift+U — Toggle Ship Specs window
• Works in both cockpit and map views
• Plain U (without Shift) still toggles Ship Systems

Menu Integration

Added to View menu after “Ship Systems”:

Ship Specs    Shift+U

Checkmark synced with shipSpecsVisible state.

Window Properties

Property	Value
Default position	top: 48px, left: 700px
Width	340px
Draggable	Yes (position persisted)
Close button	× (top-right)

Module Exports

From shipSpecs.js:

• createShipSpecsContent(container) — Build all 3 tab DOMs, return refs object
• updateShipSpecs(refs, shipData, orbitalData) — Update Performance tab values each tick