Lots. It depends where you are going. Commonly you need to specify a positional standard with 3 coordinates, and a time reference. For navigation on the Earth, latitude, longitude, altitude and local 'Universal' time is the common standard. For navigation in the solar system, there are several good candidates. For near-Earth navigation, you can use the local spacecraft coordinates where locations in space are given relative to the spacecraft's Yaw, Pitch and Roll angular coordinates and an altitude above the Earth at a given time, making 5 coordinates, called the spacecraft quaternion. The locations of objects have to be recomputed from second to second using a fast computer. Another coordinate system is the Ecliptic Coordinate system based on the plane of the solar system with the Sun at the center. This has two angular coordinates, ecliptic latitude and longitude, a distance from the Sun, and a time reference such as Universal Time ( the same one we use on Earth). Finally, for star travel, I would imagine using either something like the ecliptic coordinate system for journeys to the nearest stars, or a Galactic coordinate system referenced to the center of the Milky Way. Astronomers already use 'galactic coordinates ' which are a longitude measured with zero located on a meridian that passes through the center of the galaxy as seen from Earth, and a latitude above and below the galactic plane, but a true Galactic coordinate system would have to have the center of its spherical system at the Galactic center, not at the Earth. The Earth would be the obvious marker to define the standard meridian of zero longitude. You would also need a distance from the center of the galaxy, and a time. This would provide 2 angles, a distance and a time = 4 coordinates. No one is likely to ever use such a coordinate system for a few thousand years of so! Except in science fiction where Captain Picard is constantly giving Stardate, a distance and two angles in his 'starship-centered' navigational coordinate system. This is the conventional '2-angle, distance, time' system used over and over again. I suspect their navigational coordinates, carried with the ship, use various navigational beacons sprinkled throughout federation space, to establish some reference point, just the way we often use Polaris for navigating on the Earth, or Canopus, for navigating in the solar system.