Spacecraft are vehicles designed for travel or operation in outer space. They can be manned or unmanned and are used for a variety of purposes, including communication, exploration, observation, and research. Spacecraft can vary greatly in size, shape, and capabilities, depending on their intended mission. They are typically equipped with instruments and systems that enable them to function in the harsh environment of space, such as solar panels for power generation and propellant for maneuvering. Spacecraft can be launched into space using rockets or other launch vehicles and may operate in low Earth orbit, geostationary orbit, or interplanetary space.