Suitability of high porosity open-cell metal foams as radiant fins in passive cryogenic radiators has been studied. Copper foam having 94: 9% porosity and 20 PPI pore density has been used for this purpose. The details of the experimental set-up devised to measure the radiative cooling capacity of metal foam have been presented. The tests have been conducted in the temperature range of 170 230 K attained by foam when subjected to a radiative background of liquid nitrogen temperature ( 77 K). Concurrently, the radiative cooling capacity has been predicted computationally using the three-dimensional X-ray micro-computed tomographic image of the tested foam sample.