In the framework of the scientific co-operation agreement between the Italian Research Council and the Russian Academy of Sciences, a common research program was developed by our two Institutes to analyze the characteristics and the applications of advanced spaceborne optical sensors for the remote sensing of the environment. This program has become a part of the international scientific project PRIRODA. The space module PRIRODA, attached to the inhabited space platform MIR, is the technical base for the project. By means of the optical sensors placed on board of the PRIRODA module, we are studying the geophysical parameters useful for environmental monitoring and resources evaluation, with particular attention paid to: (a) water quality in the coastal zone and particularly near the river estuaries; (b) vegetation stress due to the anthropogenic activities; (c) geophysical studies in areas of geothermal and volcanic activities; (d) estimation and verification of the atmosphere contributions. In order to achieve the aforementioned goals, the Italian side has identified some test sites, located mainly in the Tuscany region (Italy), and the kind of needing data. The following optical sensors, of the PRIRODA module, have being utilized: (1) MOMS-2P. This modular optoelectronic multispectral stereo scanner consists of two sub-units: a threefold stereoscopic imaging system and a four-band multispectral camera with nadir orientation. The instrument parameters were designed in order to fill the gap between existing spaceborne system and airborne photography. (2) MSU-E. This electro-optical scanner is mainly devoted to investigate the reflected solar radiation in the 'atmosphere-Earth surface' system at a spatial resolution of 25 m in three visible and near infrared spectral bands. (3) MSU-SK. This opto-mechanical scanner operates in four adjacent visible and near infrared bands at 120 m of spatial resolution plus one band in the thermal infrared region with 300 m of spatial resolution. An additional feature consists of the possibility to tilt the field of view of the scanner up to 30 degrees in the plane normal to the flight direction. The results obtained from the data acquired by these sensors in March 1997 and February 1998 are discussed and compared with those collected by other aerospace sensors, like the Thematic Mapper, and in field measurements.