This book describes and reviews observations and investigations of the unique object SS433 obtained after 23 years of studying the massive binary system.The main difference between SS433 and other known X-ray binaries is the action of a constant supercritical regime for the accretion of gas onto the relativistic star (most likely a black hole) which has led to the formation of a supercritical accretion disk and collimated relativistic jets. The properties of jets are to a large extent determined by their interaction with disk wind. The precession of the disk and jets as well as the eclipsing...