Thanks to post-flight analyses of several artificial satellites carried out during last years, the meteoroids hazard for space navigation and in-orbit satellites permanence is now clear. Even if catastrophic impact is a rare event, high meteoroids fluxes can erode and weaken the satellite or space station main structures. However, the main danger seems to be the impact-generated plasma, which c...

one of the difficulties in using absolute altitudes is the separation between the mean open sealevel and geoid. theoretically, geoid is the base level in absolute altitudes, but practically, the mean open sealevel is used as a base level for absolute altitudes. the difference between these two levels is called as the seasurface topography. in this research, it is dealt the mean sea level modeli...

Abstract We construct infinitely many families of Lorenz knots that are satellites but not cables, giving counterexamples to a conjecture attributed Morton. amend the state satellite have companion knot, and pattern equivalent knot. show this amended holds very broadly: it is true for all obtained by high Dehn filling on parent link, other examples.

The natural satellites of planets in the solar system display a rich variety of orbital configurations and surface characteristics that have intrigued astronomers, physicists, and mathematicians for several centuries. As detailed information about satellite properties have become available from close spacecraft reconnaissance, geologists and geophysicists have also joined the study with conside...

In this paper, we consider a scheduling problem for a set of agile Earth observation satellites for scanning  different parts of the Earth’s surface. We assume that preemption is allowed to prevent repetitive images and develop four different preemption policies. Scheduling is done for the imaging time window and transmission time domain to the Earth stations as well. The value of each picture ...