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A resultant gravitational force due to the current estimates of the virial mass of the Milky Way galaxy, dominated by dark matter, is estimated near the Sun and is described in two different analytical models yielding consistent results. One is a two step Hernquist model, the other is a Navarro–Frenk–White model. The effect of this force is estimated on trajectories for spacecraft sufficiently far from the Sun. The difficulty of detecting this force is studied. It is concluded that its effect should be considered for certain spacecraft missions. Its effect on the Pioneer and New Horizons spacecrafts is discussed. A future mission is discussed that may be able to detect this force. Implications of this force are discussed with its impact for problems in planetary astronomy and astrophysics. [ABSTRACT FROM AUTHOR]

Abstract: A special set of solutions governing the motion of a particle, subject to the gravitational attractions of the Earth, the Moon, and, eventually, the Sun, is discussed in this paper. These solutions, called resonant orbits, correspond to a special motion where the particle is in resonance with the Moon. For a restricted set of initial conditions the particle performs a resonance transition in the vicinity of the Moon. In this paper, the nature of the resonance transition is investigated under the perspective of the dynamical system theory and the energy approach. In particular, using a new definition of weak stability boundary, we show that the resonance transition mechanism is strictly related to the concept of weak capture. This is shown through a carefully computed set of Poincaré surfaces, at different energy levels, on which both the weak stability boundary and the resonant orbits are represented. It is numerically demonstrated that resonance transitioning orbits pass through the weak stability boundaries. In the second part of the paper the solar perturbation is taken into account, and the motion of the resonant orbits is studied within a four-body dynamics. We show that, for a wide class of initial conditions, the particle escapes from the Earth–Moon system and targets an heliocentric orbit. This is a free ejection called a ballistic escape. Astrodynamical applications are discussed. [Copyright &y& Elsevier]

In recent years the application of methods of chaos theory to astrodynamics has produced new revolutionary types of low energy trajectories in space with important applications. They have uncovered new routes to the Moon demonstrated by various spacecraft-the Japan Hiten in 1991 and the European SMART-1 in 2004. These applications have also played an important role in a new theory on the origin of the Moon. [ABSTRACT FROM AUTHOR]

The article discusses various reports published within the issue, including one on applications of astrodynamic systems and another on low energy transfers.

The article discusses various reports published within the issue, including one on the applications of dynamical systems in astrodynamics and another on navigation and control.