DOI

https://doi.org/10.48717/zj40-nm40

Project

EP129

Title

JUICE calibrators

Abstract

The ESA's JUICE mission is en route to Jupiter and its icy Galilean moons, with an arrival scheduled for 2031. One of the 11 science experiments is PRIDE, aiming at improving spacecraft space vector and providing ultra-precise estimates of planetary body ephemerides based on VLBI measurements using extragalactic radio sources via phase referencing, and Doppler measurements of the carrier signal. This will enhance the science output of the mission in synergy with other on-board experiments. JUICE will perform a series gravity assist manoeuvres. The flyby at Venus on 31 Aug 2025 is a unique and crucial opportunity for a full dress rehearsal of PRIDE operations to be conducted later in the Jovian system, but has scientific value in its own right: state estimation from the flyby, especially if involving in-beam phase referencing, promises an accurate independent validation of the ephemeris solution for Venus. The goals of this proposal are (1) linking known X-band VLBI sources as potential phase calibrators within 1deg from JUICE trajectory in a 5-day period around the Venus flyby to ICRF, and (2) checking the VLBI decectability of selected potential in-beam phase-reference sources within 4' along the JUICE track.