A spacecraft (Hebrew: חללית, Chalalit; Russian: космический аппарат, kosmicheskiy apparat; Chinese: 航天器, Hángtiānqì) is a vehicle or machine designed to fly in outer space. Spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, planetary exploration, and transportation of humans and cargo. There are two major types of spacecraft: manned (or crewed) and unmanned (or robotic). Manned spacecraft are designed to carry humans, such as the Space Shuttle or the International Space Station (ISS), while unmanned spacecraft operate autonomously or are controlled remotely, like satellites or probes. Key components of a spacecraft include a propulsion system, power source, communication system, and scientific instruments or payload, depending on its mission. Spacecraft must withstand extreme conditions, such as radiation, temperature fluctuations, and microgravity, making their design and construction highly specialized and complex.