Spacecraft systems refer to the various components and technologies that work together to enable a spacecraft to operate in space. These systems include propulsion, power generation, communication, and thermal control. Each system plays a crucial role in ensuring the spacecraft can travel, communicate with Earth, and maintain a suitable environment for its instruments and crew. Additionally, spacecraft systems are designed to handle the unique challenges of space, such as vacuum conditions and extreme temperatures. For example, the International Space Station relies on advanced life support systems to provide air and water for astronauts. Overall, effective spacecraft systems are essential for successful space missions.