{"dataset":{"slug":"navigation-methods","title":"Navigation Methods","description":"Deep-space navigation systems — radiometric tracking, Delta-DOR, optical, and autonomous navigation.","version":"1.0.0","lastGenerated":"2026-06-29","license":"CC BY-SA 4.0","entityCount":7,"sources":["nasa","jpl"]},"entities":[{"id":"navigation_system:autonomous-navigation","name":"Autonomous Navigation","type":"navigation_system","domain":"science","description":"Onboard software that processes optical-navigation images in real time and steers the spacecraft itself, without waiting for commands from Earth. It was pioneered by Deep Space 1 and used for terminal guidance in fast flybys and the DART impact.","entryPath":"/deep-space-network/navigation/autonomous-navigation"},{"id":"navigation_system:deep-space-atomic-clock","name":"Deep Space Atomic Clock","type":"navigation_system","domain":"science","description":"A miniaturised, ultra-stable atomic clock small enough to fly on a spacecraft. By putting precise timekeeping onboard, it enables one-way radiometric navigation — the spacecraft can determine its own position without the round-trip to a ground clock — a technology demonstrated in Earth orbit.","entryPath":"/deep-space-network/navigation/deep-space-atomic-clock"},{"id":"navigation_system:delta-dor","name":"Delta-DOR","type":"navigation_system","domain":"science","description":"A precise angular-position technique: two widely separated stations record the spacecraft's signal and that of a distant quasar, and the tiny difference in arrival times pins down the spacecraft's position on the sky to a few nanoradians — vital for accurate planetary arrivals.","entryPath":"/deep-space-network/navigation/delta-dor"},{"id":"navigation_system:inertial-navigation","name":"Inertial Navigation","type":"navigation_system","domain":"science","description":"Gyroscopes and accelerometers in an inertial measurement unit that sense a spacecraft's rotation and acceleration, propagating its orientation between star-tracker updates and through manoeuvres when other references are unavailable.","entryPath":"/deep-space-network/navigation/inertial-navigation"},{"id":"navigation_system:optical-navigation","name":"Optical Navigation","type":"navigation_system","domain":"science","description":"Using a spacecraft's own camera images of a target body against the background stars to determine its position relative to that body — essential in the final approach to an asteroid, comet, or moon, where ground tracking alone is not precise enough.","entryPath":"/deep-space-network/navigation/optical-navigation"},{"id":"navigation_system:radiometric-navigation","name":"Radiometric Navigation","type":"navigation_system","domain":"science","description":"Measuring a spacecraft's distance and velocity from its radio signal — range from the round-trip signal time, and line-of-sight velocity from the Doppler shift. Combined over time from the ground stations, these fix a spacecraft's trajectory across the Solar System.","entryPath":"/deep-space-network/navigation/radiometric-navigation"},{"id":"navigation_system:star-tracker","name":"Star Tracker","type":"navigation_system","domain":"science","description":"A small camera that identifies star patterns to determine which way a spacecraft is pointed, to a fraction of an arcsecond. Star trackers give the precise attitude a spacecraft needs to aim its high-gain antenna at Earth and its instruments at a target.","entryPath":"/deep-space-network/navigation/star-tracker"}]}