A Possible Test of the J2c−2 General Relativistic Orbital Effects with Juno

Abstract

For the first time, the 1PN J2c−2 effects could be measured by the Juno mission in the gravitational field of Jupiter during its nearly yearlong science phase thanks to the high eccentricity (e = 0.947) of the spacecraft's orbit and to the huge oblateness of Jupiter (J2 = 1.47 × 10−2). A numerical analysis shows that the expected J2c−2 range-rate signal for Juno should be as large as ≈ 280 microns per second (μm s−1) during a typical 6 h pass at its closest approach to Jupiter. The radio science apparatus of Juno should reach an accuracy in Doppler range-rate measurements of ≈ 1 – 5 μm s−1 over such passes. The range-rate signature of the classical even zonal perturbations is different from the J2c−2 one. Thus, further investigations, based on covariance analyses of simulated Doppler data and dedicated parameters estimation, are worth of further consideration.