Orbit determination for space missions in Pisa: results and simulations from Juno and BepiColombo
Abstract
The gravitational field of a planet is the main source of information about its interior structure, providing, e.g., constraints on the core size or the state of rotation. The most effective way to map a planet's gravity is by means of an orbiter which is endowed with a radio communication system. The radio link allows measurements of the spacecraft's range and range-rate, which can be used to reconstruct its orbit and ultimately to determine a number of physical parameters relative to the planet, including the coefficients of its gravitational field's spherical harmonic expansion. The same data can be used to undertake fundamental physics experiments, like the determination of the parameters relative to the Parametrized Post-Newtonian formulation of the metric theories of gravity. The aim of this presentation is to summarize the main results about the Radio Science Experiments of the NASA's Juno mission, now orbiting Jupiter, and the ESA/JAXA's BepiColombo mission, launched in October 2018 to reach Mercury in 2025, obtained at the University of Pisa using the self-developed ORBIT14 orbit determination code. As regards the Juno mission, we show a solution of Jupiter's gravity field obtained by analysis of real data from the first two Juno gravity orbits, and compare it to the one obtained with the JPL's operative software MONTE ([1]). As far as the BepiColombo mission is concerned, we present numerical simulations of the Superior Conjunction Experiment for the determination of the PPN parameter γ, related to the space-time curvature.
[1] Iess et al., Nature 555, 220-222 (2018)- Publication:
-
AAS/Division of Dynamical Astronomy Meeting
- Pub Date:
- June 2019
- Bibcode:
- 2019DDA....5020005S