The BepiColombo solar conjunction experiments revisited. (arXiv:2201.05107v1 [gr-qc])
<a href="http://arxiv.org/find/gr-qc/1/au:+Stefano_I/0/1/0/all/0/1">Ivan di Stefano</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Cappuccio_P/0/1/0/all/0/1">Paolo Cappuccio</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Iess_L/0/1/0/all/0/1">Luciano Iess</a>
BepiColombo ESA/JAXA mission is currently in its 7 year cruise phase towards
Mercury. The Mercury orbiter radioscience experiment (MORE), one of the 16
experiments of the mission, will start its scientific investigation during the
superior solar conjunction (SSC) in March 2021 with a test of general
relativity (GR). Other solar conjunctions will follow during the cruise phase,
providing several opportunities to improve the results of the first experiment.
MORE radio tracking system allows to establish precise ranging and Doppler
measurements almost at all solar elongation angles (up to 7-8 solar radii),
thus providing an accurate measurement of the relativistic time delay and
frequency shift experienced by a radio signal during an SSC. The final
objective of the experiment is to place new limits to the accuracy of the GR as
a theory of gravity in the weak-field limit. As in all gravity experiments,
non-gravitational accelerations acting on the spacecraft are a major concern.
Because of the proximity to the Sun, the spacecraft will undergo severe solar
radiation pressure acceleration, and the effect of the random fluctuations of
the solar irradiance may become a significant source of spacecraft buffeting.
In this paper we address the problem of a realistic estimate of the outcome of
the SSC experiments of BepiColombo, by including in the dynamical model the
effects of random variations in the solar irradiance. We propose a numerical
method to mitigate the impact of the variable solar radiation pressure on the
outcome of the experiment. Our simulations show that, with different
assumptions on the solar activity and observation coverage, the accuracy
attainable in the estimation of $gamma$ lays in the range $[6,
13]cdot10^{-6}$.
BepiColombo ESA/JAXA mission is currently in its 7 year cruise phase towards
Mercury. The Mercury orbiter radioscience experiment (MORE), one of the 16
experiments of the mission, will start its scientific investigation during the
superior solar conjunction (SSC) in March 2021 with a test of general
relativity (GR). Other solar conjunctions will follow during the cruise phase,
providing several opportunities to improve the results of the first experiment.
MORE radio tracking system allows to establish precise ranging and Doppler
measurements almost at all solar elongation angles (up to 7-8 solar radii),
thus providing an accurate measurement of the relativistic time delay and
frequency shift experienced by a radio signal during an SSC. The final
objective of the experiment is to place new limits to the accuracy of the GR as
a theory of gravity in the weak-field limit. As in all gravity experiments,
non-gravitational accelerations acting on the spacecraft are a major concern.
Because of the proximity to the Sun, the spacecraft will undergo severe solar
radiation pressure acceleration, and the effect of the random fluctuations of
the solar irradiance may become a significant source of spacecraft buffeting.
In this paper we address the problem of a realistic estimate of the outcome of
the SSC experiments of BepiColombo, by including in the dynamical model the
effects of random variations in the solar irradiance. We propose a numerical
method to mitigate the impact of the variable solar radiation pressure on the
outcome of the experiment. Our simulations show that, with different
assumptions on the solar activity and observation coverage, the accuracy
attainable in the estimation of $gamma$ lays in the range $[6,
13]cdot10^{-6}$.
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