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We report on a new test of the gravitational redshift and thus of local position invariance, an integral part of the Einstein equivalence principle, which is the foundation of general relativity and all metric theories of gravitation. We use data spanning 1008 days from two satellites of Galileo, Europe’s global satellite navigation system (GNSS), which were launched in 2014, but accidentally delivered into elliptic rather than circular orbits. The resulting modulation of the gravitational redshift of the onboard atomic clocks allows the determination of redshift with high accuracy.

The purpose of this study was to define the a communication subsystem architecture (including both ground and space segments, as well as operational methods) that allows robust RF TT&C links during superior solar conjunction phases. The defined architecture shall ensure robust and reliable links in scintillation regimes (i.e. at low SEP angles) where TT&C links are nowadays degraded, leading to occasional link interruptions. Similarly, the defined architecture shall ensure that at even higher scintillation regimes (i.e.

The project is dedicated to an in-depth study of the re-entry of ESA's Gravity Field and Steady-State Ocean Circulation Explorer (GOCE), for which a rich measurement dataset is available up to the very end of its decay phase.

The difficult and costly access to reliable and quality Earth Observation (EO) satellite data has historically often limited the development of operational and sustainable services in multiple application domains (among which Disaster Risk Management) and, as a consequence, it has impaired the benefit that the society could have been receiving back as a return of huge multi annual investments in the space sector.