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Large satellite constellations in low-Earth orbit seek to be the infrastructure for global broadband Internet and other telecommunication needs. We briefly review the impacts of satellite constellations on astronomy and show that the Internet service offered by these satellites will primarily target populations where it is unaffordable, not needed, or both. The harm done by tens to hundreds of thousands of low-Earth orbit satellites to astronomy, stargazers worldwide, and the environment is not acceptable.
In this work we apply generalized A. Sparavigna method (use of freely available softwares (programs), e.g. http://www.sollumis.com/, http://suncalc.net/#/44.557,22.0265,13/2014.12.29/09:22, http://universimmedia.pagesperso-orange.fr/geo/loc.htm, http
In this paper we use a variation of simulated annealing algorithm for optimizing two-dimensional constellations with 32 signals. The main objective is to maximize the symmetric pragmatic capacity under the peak-power constraint. The method allows the
We argue that light sails that are rapidly accelerated to relativistic velocities by lasers must be significantly curved in order to reduce their mechanical stresses and avoid tears. Using an integrated opto-thermo-mechanical model, we show that the
Millisecond pulsars (MSPs) have a great potential to set standards in timekeeping, positioning and metadata communication.
Parabolic flights provide cost-effective, time-limited access to weightless or reduced gravity conditions experienced in space or on planetary surfaces, e.g. the Moon or Mars. These flights facilitate fundamental research - from materials science to