Testing the gravitational redshift with an inner Solar System probe: The VERITAS case
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Author/Creator ORCID
Date
2023-03-13
Type of Work
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Citation of Original Publication
De Marchi, Fabrizio, et al. "Testing the gravitational redshift with an inner Solar System probe: The VERITAS case" PHYSICAL REVIEW D 107, no. 6 (15 March 2023). https://doi.org/10.1103/PhysRevD.107.064032.
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This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.
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Public Domain Mark 1.0
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Abstract
The NASA Discovery-class mission VERITAS, selected in June 2021, will be launched toward Venus
after 2027. In addition to the science instrumentation that will build global foundational geophysical
datasets, VERITAS proposed to conduct a technology demonstration for the Deep Space Atomic Clock
(DSAC-2). A first DSAC successfully operated in low-Earth orbit for more than two years, demonstrated
the trapped ion atomic clock technology, and established a new level of performance for clocks in space.
DSAC-2 would have further improvements in size, power, and performance. It would host a 1 × 10⁻¹³
grade USO to produce a frequency output with short-term stability of less than 2 × 10⁻¹³/ √τ (where τ is
the averaging time). However, due to funding shortfalls, DSAC-2, had to be canceled. The initially foreseen
presence of an atomic clock on board the probe, however, raised the question whether this kind of
instrumentation could be useful not only for navigation and time transfer but also for fundamental physics
tests. In this work, we consider the DSAC-2 atomic clock and VERITAS mission as a specific example to
measure possible discrepancies in the redshift predicted by general relativity by using an atomic clock
onboard an interplanetary spacecraft. In particular we investigate the possibility of measuring possible
violations of the local Lorentz invariance and local position invariance principles. We perform accurate
simulations of the experiment during the VERITAS cruise phase. We consider different parametrizations of
the possible violations of the general relativity, different operational conditions, and several different
assumptions on the expected measurement performance. We show that DSAC-2 onboard VERITAS would
provide new and improved constraints with respect to the current knowledge. Our analysis shows the
scientific value of atomic clocks like DSAC-2 hosted onboard interplanetary spacecraft.