  The NASA Discovery-class mission VERITAS, selected in June 2021, will be
launched towards 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
$1\times{10}^{-13}$ grade USO to produce a frequency output with short-term
stability of less than $2\times{10}^{-13}/\sqrt\tau$ (where $\tau$ 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. Our analysis shows the scientific value of
atomic clocks like DSAC-2 hosted onboard interplanetary spacecraft.
