Direct Line-of-Sight Umbra
Geometric no-direct-line-of-sight zone using finite source size. A full umbra exists only when shield half-size > source half-size; radiators must fit within it at the near end (narrowest point). This is a geometry model — real reactor shielding also needs gamma/neutron attenuation, scattering, and leakage analysis.
Shield Shape
Shield Radius m
2.00 m
Source Half-Size (reactor/engine radius) m
0.30 m
Source-to-Shield Distance m
10.0 m
Radiator Near End (from shield) m
2.0 m
Radiator Far End (from shield) m
14.0 m
Radiator Architecture
Thermal-transport design. Heat Pipe is the default — it keeps fin efficiency near 1.0 at any panel width. Flat Conductive Panel models a spreader-equipped honeycomb sandwich; passive sheets without internal spreaders would perform significantly worse.
Material & Coolant
Selecting a radiator architecture above populates this list with physically meaningful material + working-fluid combinations. The chosen combination sets the operating-temperature range, fin conductivity, and skin density.
Arrangement Pattern
Surface & Thermal Properties
Radiator Operating Temperature K
350 K
Surface Emissivity (ε) —
0.88
Solar Absorptivity (α) —
0.12
Face Sheet / Fin Thickness mm
Thickness of the radiating skin/fin material. Skin mass = selected material density × thickness × deployed face area × architecture skin multiplier (pin fins use ×2.2 to account for their 3D surface volume). Architecture core hardware mass is added separately.
Thickness of the radiating skin/fin material. Skin mass = selected material density × thickness × deployed face area × architecture skin multiplier (pin fins use ×2.2 to account for their 3D surface volume). Architecture core hardware mass is added separately.
1.5 mm
Active Radiating Sides
Environment / Orbit
Mission Environment Preset
Solar Flux (direct) W/m²
0 W/m²
Sun Incidence Angle (from normal) deg
90 deg
0° = sun broadside on the radiator face (worst case); 90° = edge-on to the sun (no direct solar load — the usual design goal). Direct solar scales with cos θ.
Albedo Flux (reflected planetary) W/m²
0 W/m²
Planet IR Effective Temp K
4 K
Planet IR View Factor (F) 0–1
0.00
Net Heat Rejection
—
kilowatts (kW)
System Mass
—
kilograms (kg)
Deployed Face Area
—
m² projected (ideal plates)
Specific Power
—
W / kg
Fin Efficiency η
—
dimensionless (0–1)
Configure parameters and press CALCULATE LAYOUT
Finite-source umbra · two-sided radiation with self-view · solar/planet environment · fin efficiency