Space laboratory is a manned spaceflight vehicle designed for carrying out space experimental activities. It is smaller than space station in scale, and is the prototype of space station. The main missions include breakthrough and mastery of spaceflight vehicles’ space rendezvous& docking and assembly control technologies; breakthrough of key technologies relating to astronauts’ mid-term space staying, long-term auto flight of space vehicles, regenerative life support system and cargo spaceship replenishment; demonstrating the performance and function of cargo spaceships transportation between earth and space; preliminary investigation of key technologies relating to space station construction.