A cubic satellite has a projected area of facing the Sun and a total exterior surface…

PHYSICS · Subjective · A Level · Physics · Further mechanics and thermal physics · Further mechanics and thermal physics

Problem

A cubic satellite has a projected area of

2.0\,\text{m}^2

facing the Sun and a total exterior surface area of

6.0\,\text{m}^2

. The absorptivity for solar radiation is

0.20

, and the surface emissivity is

0.70

. The satellite orbits where the solar intensity is

1.4\times10^{3}\,\text{W\,m}^{-2}

. If the mission requires the satellite body to remain at

300\,\text{K}

, determine the minimum electrical heater power that must be supplied internally to maintain this temperature.