Simultaneous Measurement of Solar Absorptance and Total Hemispherical Emittance

An onboard simultaneous measuring method of solar absorptance α_S and total hemispherical emittance εH for thermal control materials is proposed. This method allows to determine α_S and ε_H simultaneously by giving different levels of input power to a sheet heater attached to the sample, and there is no need to use the values of the mass or the specific heat of the sample materials for the data reduction. In order to verify this method on the ground, the parameters α_S and ε_H are measured for three kinds of thermal control materials.