Regular, long-term, global-scale measurements of atmospheric minor gaseous and aerosol composition (MGAC) by means of different instruments (PHOENIX, OZONE-MIR, ISTOK- 1, DOPI) are planned on board the SPECTR and PRIRODA modules of the Space Station MIR during 1995-1998. The main characteristics of these devices are given. The principal goals of the space experiments are: investigations of the spatial and temporal MGAC variations, comparisons of different space-borne atmospheric chemistry sensors and their intercalibration, validation of the space MGAC measurements using different ground-based station and aircraft data, and studies of the molecular absorption in the atmosphere aimed to enhance an accuracy of radiative transfer atmospheric models. Special attention is devoted to radiative transfer model (line-mixing, line-shift, line-narrowing, non-LTE effects). The numerical estimations of the errors of the MGAC vertical profile retrievals using different device data are carried out.