Astronauts navigate in space using a combination of advanced technologies and techniques:

1. Inertial Navigation Systems (INS): Spacecraft uses gyroscopes and accelerometers to track their orientation and movement. This system helps determine their position and velocity relative to a reference point, even without external landmarks.

2. Star Trackers: Spacecraft are equipped with star trackers that capture images of stars to help determine their orientation and position in space. By comparing star positions to a star catalog, the system calculates the spacecraft’s orientation.

3. Ground-Based Tracking: Mission control centers on Earth track the spacecraft using radar and radio signals. They provide astronauts with real-time data on their trajectory and position, assisting with navigation and course corrections.

4. Navigation Computers: Spacecraft are equipped with onboard computers that process data from INS, star trackers, and ground stations to calculate and adjust the spacecraft’s trajectory.

5. Visual Navigation: For missions closer to celestial bodies like the Moon or Mars, astronauts can use visual cues and images from onboard cameras to assist with navigation and landing procedures.

These methods work together to ensure precise navigation and successful mission operations in the vastness of space.