Abstract <p>A scientific equipment was developed by the Lebedev Physical Institute for the Solntse-Terahertz space experiment to be installed onboard the Russian segment of the International Space Station. The experiment aims to collect data on the Sun’s terahertz radiation and to study solar active regions and solar flares. The Solntse-Terahertz scientific apparatus includes eight detection channels sensitive to radiation at frequencies ranging from 0.4 to 12.0 THz. A blackbody simulator (BBS) was used to experimentally calibrate the equipment. The calibration factors for each channel were determined by calculating, with numerical integration methods, the correlation between the intensity of BBS radiation passing through a filter system and the equipment’s response to BBS radiation found experimentally. The original BBS spectrum was successfully recovered to verify the quality of the calibration.</p>