Radiator net heat flux

Net W/m² of a flat radiator: Stefan-Boltzmann emission per face minus absorbed sun, albedo and Earth IR (view factor); area per kW.

SIDUS educational calculator. Category utilities. Tags: LEO, operations, power, satellite, thermal, utilities. Pure SI. Not flight software.

Formula

q = nεσT⁴ − αS f − F(αaS + α_ir σT_e⁴)

Radiator net flux and m² per kW

Primary sources

• Spacecraft Thermal Control Handbook, Vol. I (D. G. Gilmore (ed.), The Aerospace Press / AIAA): Radiator environment loads (solar, albedo, Earth IR, view factors), pumped loops, heat pumps.
• Orbital Data Centers: Spacecraft Constraints and Economic Viability (S. G. Turyshev, arXiv:2604.27197 (2026)): Lumped radiator closure A = P / (ε η σ T⁴ − q_env), environmental load decomposition, 1 MW base case (2.50e3 m², 29.4 kg/kW).
• Why we should train AI in space (white paper) (Lumen Orbit / Starcloud: Feilden, Oltean, Johnston (September 2024)): Worked radiator example (ε 0.92, α 0.09, F 0.25, 20 °C), 5 GW / 4 km × 4 km array, dawn-dusk SSO rationale, shield scaling. SIDUS reimplements the physics independently and applies ε to the Earth-IR term by default. No affiliation.
• Solar Absorptance and Thermal Emittance of Some Common Spacecraft Thermal-Control Coatings (J. H. Henninger, NASA RP-1121 (1984)): α / ε presets: Z-93 0.17/0.92, S-13G 0.20/0.90, silver Teflon 5 mil 0.08/0.81, Chemglaze Z306 0.96/0.91. No affiliation.
• SIDUS pure-SI implementation (sidus.tools): Local pure-function implementations in src/lib/physics (educational, independent reimplementation).

How do AI agents use this tool?

Read /llms.txt or call https://sidus.tools/api/mcp. Open the interactive page for live SI inputs.