Thermal Control System Calculator

Size radiators and thermal control for space habitats based on crew, equipment heat, and solar exposure.

Crew size

Equipment power (kW)

Habitat surface area (m²)

Solar exposure fraction (0-1)

Target temperature (°C)

Tab to move between fields

Heat to reject (kW)

15.6

Internal heat (kW)15.6

Solar heat absorbed (kW)0

Radiator area (m²)32.9

Coolant pump power (kW)0.31

System mass (kg)177

How to Use This Calculator

Enter the total internal heat load in watts (crew metabolism + electronics + lights).
Set the habitat external environment: orbital eclipse fraction or planetary surface temperature.
Input radiator area in square meters and emissivity of the radiator surface.
Review the radiator heat rejection capacity and whether it meets the heat load.
Add a fluid loop heat exchanger if active cooling is needed to supplement passive radiators.

How the result changes with Equipment power (kW)

Crew size: Number of crew members.
Equipment power (kW): Total electrical power of onboard equipment.
Habitat surface area (m²): External surface area of habitat.
Solar exposure fraction (0-1): Fraction of surface exposed to sun (0.5 typical).
Target temperature (°C): Desired habitat temperature.

Identify Input Parameters
4 parameters
Crew size = 6, Equipment power (kW) = 15, Habitat surface area (m²) = 200, Solar exposure fraction (0-1) = 0.5 = 5 input(s) provided
Calculate Heat to reject
Heat to reject
15.6 = 15.6
Calculate Internal heat
Internal heat = crewHeatKw + equipmentPowerKw
15.6 = 15.6
Calculate Solar heat absorbed
Solar heat absorbed = habitatSurfaceAreaM2 * solarExposure * 1.361 * 0.3 / 1000
0 = 0