Communication System Considerations For Manned Orbiting Laboratory Stations

This paper discusses the philosophy of communication systems design for space stations currently under study, such as MORL, LORL and other similar concepts. For the early stations, the communication systems will make use of off-the-shelf equipment. The communication requirements existing for th& different station concepts is summarized. The most important factors for choosing the communication system meeting the requirements are discussed. A communication system for an early two man laboratory is presented, and its primary features are discussed. Finally the problem of accommodating the different kinds of telemetry data in a composite spectrum is discussed

Experimental and Theoretical Charge Density Studies of 8-Hydroxyquinoline Cocrystallized with Salicylic Acid

The experimental electron density distribution (EDD) in 8-hydroxyquinoline cocrystallized with salicylic acid, 1, has been determined from a multipole refinement of high-resolution X-ray diffraction data collected at 100 K. The experimental EDD is compared with theoretical densities resulting from high-level ab initio and BHandH calculations using Atoms in Molecules theory. 1 crystallizes in the triclinic crystal system, and the asymmetric unit consists of a neutral salicylic acid molecule, a salicylate anion, and an 8-hydroxyquinolinium cation exhibiting a number of inter- and intramolecular hydrogen bonds and π–π interactions. Topological analysis reveals that π–π interactions are of the “closed-shell” type, characterized by rather low and flat charge density. In general, the agreement of the topological values (ρbcp and 2ρbcp) between experiment and theory is good, with mean differences of 0.010 e Å–3 and 0.036 e Å–5, respectively. The energetics of the π–π interactions have been estimated, and excellent agreement is observed between the relative energy and the strength of π-stacking derived from the Espinosa approach, with an average difference of only 4.4 kJ mol–1