Conception of a space patrol system destined to discover celestial bodies that may be dangerous for Earth is considered. The patrol system consisting of several spacecrafts located on the Earth orbit around the Sun with space telescopes onboard will allow to discover asteroids approaching the Earth orbit. The overwhelming majority of such bodies with diameters ≥ 200-500 m may be defined during 5-6 years and the catalogue of their orbits may be done. Some known scientific programs of observing such celestial bodies from the Earth supposes to make a catalogue of ≈ 95% of bodies with diameter ≥ 1 km till 2010 year. Hence the system of space observation may be considered as the following step in the program of observation of dangerous objects.
Our conception is based on the theory of origin of dangerous asteroids and evolution of their orbits. Description of “optical barrier” created by patrol system is given and some principal parameters of the system are analyzed. It’s proved that the system of space telescopes may be put on the necessary orbits with the help of spacecraft with electro-rocket propulsion. The project of such spacecraft is now worked out for the expedition “Fobos-Ground”.