This paper deals with spacecraft autonomous navigation in deep space missions. The considered problem is that of spacecraft localization based on angular measurements. The dynamic model of the spacecraft accounts for several perturbing effects, such as Earth and Moon gravitational field asymmetry and errors associated with the Moon ephemerides. The measurement process is based on elevation and ...

Laser pulses fired at retroreflectors on the Moon provide very accurate ranges. Analysis yields information on Earth, Moon, and orbit. The highly accurate retroreflector positions have uncertainties less than a meter. Tides on the Moon show strong dissipation, with Q = 33 ± 4 at a month and a weak dependence on period. Lunar rotation depends on interior properties; a fluid core is indicated wit...

Mother Nature is an exceedingly exacting old lady. She guards her treasures well and does not yield them on casual inquiry. To be sure, she has spread the stuff and substance of the Universe before everyone so that it might be described and classified. For generations men have eagerly approached this monumental job until at last there is available a fairly satisfactory account of the structure ...

BACKGROUND Man, since ancient times, has been convinced of, and has researched scientific evidence that the barometric and gravitational forces play an important role in structural and biological variation of the planets, influencing the various forms of life. In particular, the synergistic relationships between variations in atmospheric pressure and gravitational forces on human gestation peri...

This research used knowledge of the indigenous practice of timing nontimber forest product harvest with the full moon to demonstrate that chemicals controlling the decomposition rate of foliage fluctuate with the lunar cycle and may have developed as a result of plant-herbivore interactions. Indigenous knowledge suggests that leaves harvested during the full moon are more durable. Palm leaves h...

Most of the craters on the surface of the Moon were created by the collision of minor bodies of the Solar System, in particular asteroids coming from the Main Belt as a consequence of different types of resonance. Our aim is to investigate the dynamics of such asteroids, paying special attention on the hyperbolic invariant manifolds associated with the equilibrium point L2 of the Earth – Moon s...

Distant Retrograde Orbits in the Earth-Moon system are gaining in popularity as stable ‘parking’ orbits for various conceptual missions. To investigate the stability of potential Distant Retrograde Orbits, simulations were executed, with propagation running over a thirty-year period. Initial conditions for the vehicle state were limited such that the position and velocity vectors were in the Ea...