Two reports, presented on the 17 Space Flight Dynamics Conference, are jointed by their attention to researches of small celestial bodies – asteroids and comets, and by supposed use of spacecrafts with low thrust for those purposes. For more than 20 years we do research the problem of flights towards asteroids of the Main Belt and comets of Jupiter group with the help of low thrust (see References). As it is supposed that above mentioned small bodies may conserve the relic matter and may carry important information about Solar System origin. Recently a conception (based on our knowledge of small bodies) of Space Patrol system for discovering of hazard asteroids approaching the Earth was formulated. It may extend known programs of optical observation of hazard objects from the Earth.