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[en] Nuclear power enables or significantly enhances a variety of space missions whether near-Earth, or for solar system exploration, lunar-Mars exploration and recovery of near-Earth resources. Performance optimizations for individual missions leads to a large number of power and propulsion systems to be developed. However, the realities of the budget and schedules indicates that the number of nuclear systems that will be developed are limited. One needs to seek the ''minimum requirements'' to do a job rather than the last ounce of performance, and areas of commonality. To develop a minimum number of systems to meet the overall DoD, NASA, and commercial needs, the broad spectrum of requirements has been examined along with cost drivers
[en] In this paper we shall prove that every topological space with dispersion point must be T0-space, moreover, we shall classify and describe the cardinality of the complement of the intersection of the open sets in such spaces that contain the dispersion point. (author). 10 refs
[en] There are many problems and configurations in Euclidean geometry that were never extended to the framework of (normed or) finite dimensional real Banach spaces, although their original versions are inspiring for this type of generalization, and the analogous definitions for normed spaces represent a promising topic. An example is the geometry of simplices in non-Euclidean normed spaces. We present new generalizations of well known properties of Euclidean simplices. These results refer to analogues of circumcenters, Euler lines, and Feuerbach spheres of simplices in normed spaces. Using duality, we also get natural theorems on angular bisectors as well as in- and exspheres of (dual) simplices.
[en] A scenario is presented wherein the interplanetary supply vehicles for the expansion of the Mars bases are nuclear powered-electrically propelled. For the initial build-up phase every supply vehicle need not return to earth but could be utilized as a one-way transport to Mars synchronous orbit. Upon arriving at Mars., they would land their cargos with one-way descent vehicles. Base personnel will arrive at Mars in separate 'fast trip' vehicles. Once in the Mars synchronous orbits, the nuclear power system is will longer be needed for propulsion. Thus, this power system - megawatt power range - can be used as an orbital power station beaming its power to locations on the surface of the planet. Placing a number of such power systems at strategically located synchronous orbit positions will permit coverage of the major portion of the Martian surface. The megawatt size power system for one interplanetary electric propulsion vehicle will be capable of supplying a number of surface bases of installations
[en] Kim (2008 Class. Quantum Grav. 25 238002) has recently shown how to reconstruct a globally hyperbolic spacetime with non-compact Cauchy surface Σ up to a conformal factor by considering a family of subsets of Σ. We see how this work is related to previous results on reconstructing such spacetimes up to a conformal factor from the set of skies in the space of null geodesics. (comments and replies)