Two years of Planetary Radio Interferometry and Doppler Experiment for the ESA’s JUICE mission

Ground-based radio astronomy and space science get together in the Planetary Radio Interferometry and Doppler Experiment (PRIDE), which provides the precise determination of the lateral position of spacecraft on the celestial sphere using phase referencing near-field Very Long Baseline Interferometry (VLBI).

As part of the ESA Jupiter Icy Moons Explorer (JUICE) mission, PRIDE is complementary to on-board radio science experiments. The technique consists of radio astronomical observations of the JUICE radio signal alongside calibrating quasars to deliver high-resolution lateral position measurements within the International Celestial Reference Frame. PRIDE requires no extra onboard instruments and relies on the spacecraft's existing telecommunications system and ground-based telescope arrays, like the European VLBI Network or the Australian Long Baseline Array.

Since JUICE launch, PRIDE observations have tracked the spacecraft on several occasions. During the Lunar-Earth Gravity Assist (LEGA), multiple radio telescopes observed JUICE to independently validate the spacecraft trajectory to verify PRIDE internal pipelines. In August 2025, the European VLBI Network ran an observing campaign during the Venus gravity assist manoeuvres. In this presentation, the status and the results of the PRIDE-JUICE cruise phase activities will be presented.