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Bepi Colombo: The mission, the instruments
Abstract
Despite the fact the Mercury is a small, rocky, burned planet, so close to the Sun that it is hard to be seen from Earth except during twilight, it has played a very important role in the history of astronomy and fundamental physics and plays a crucial role in the understanding of the formation and evolution of our Solar System.
... The distinctive feature of BepiColombo [1] [2] with respect to other deep-space missions is its relative proximity to the Sun. This has two fundamental consequences. ...
The key role of the Italian Spring Accelerometer (ISA) in the radio science measurements of the ESA BepiColombo mission to Mercury is to remove, a posteriori, the non-gravitational accelerations acting on the Mercury Planetary Orbiter (MPO) due to the very strong radiation environment around Mercury. This paper is devoted to describe the on-ground actuator calibration procedure along with the facility assembled to carry it out. Such a calibration is necessary to guarantee the accelerometer performance and hence to reach the very ambitious objectives of the Radio Science Experiment (RSE) of the ESA mission.
The purpose of this work is to study the interactions between the Solar Wind (SW) and Mercury and/or Mars by means of numerical simulations. In the context of previous observations made Mariner 10 and MESSENGER, and the preparation of the future mission Bepi Colombo, we developed a three-dimensional and parallel hybrid model of the interaction of the SW with Mercury's magnetosphere. We also investigated the reflection of incident particles on the Martian bow shock, using a test-particle program combined with hybrid simulation results. Despite the fact that observations are necessary for studying the interaction of the SW with a planetary obstacle, they are not sufficient and numerical modelling represents an essential tool to complete observations analysis. In the second chapter we introduce the different simulation models used to study the interactions of the SW with Mercury and Mars. We describe in particular the building steps of our Mercury hybrid model. The results concerning the hermean environment, obtained with models which preceded ours, are described in the first part of the Chapter 3. In the following of this chapter, we present our results about the intrinsic magnetic field and the magnetospheric plasma of Mercury. In the Chapter 4, we describe the hybrid model and the test-particle program we used to investigate the reflection of SW and planetary protons on the Martian bow shock. Then we exhibit the results. Although this study has been led on the Martian bow shock, it can be easily adapted on Mercury.
The design of interplanetary trajectories based on patched circular
restricted three body models is gradually becoming a valuable
alternative to the classical patched conic approach. The main advantage
offered by such a model is the possibility to exploit the manifold
dynamics to move naturally far from or toward a body. Generally,
propulsive maneuvers are required to match these structures. Low-thrust
arcs offer the possibility to have a significant propellant mass
reduction when moving from manifold to manifold. The aim of this paper
is to present a methodology to design low-thrust trajectories between
two planetary orbits connecting the manifolds of two circular three body
systems. The approach is based on a grid search on the main parameters
governing the solution to identify those trajectories moving within the
manifold images on given Poincarè sections. The value of the
Jacoby constant of the target libration point periodic orbit is chosen
as stop condition for the thrusting phases. Ballistic arcs follow up to
the proper Poincarè section intersection. A grid search for an
Earth to Venus transfer is presented as test case.
- G H Pettingill
- R B Dyce
Pettingill G. H., & Dyce, R. B. 1965, Nature
206, 1240