Cargo launch vehicles to low earth orbit

There are two primary space transportation capabilities required to support both base programs and expanded mission requirements: earth-to-orbit (ETO) transportation systems and space transfer vehicle systems. Existing and new ETO vehicles required to support mission requirements, and planned robotic missions, along with currently planned ETO vehicles are provided. Lunar outposts, Mars' outposts, base and expanded model, ETO vehicles, advanced avionics technologies, expert systems, network architecture and operations systems, and technology transfer are discussed

"Maré rosa", águas turvas: Definhamento do socialismo do século XXI?

A wide-ranging study on Latin America’s “pink tide” governments, and the social formations underpinning them, raised again the debate on 21st Century socialism. If the period 1990-2010 saw renewed popular insurgency after the Soviet bloc collapse, progressive forces have lately been confronted by low intensity reaction from the combined might of local and imperial bourgeoisies. US hegemony faces renewed anti-neoliberalism, but now assails popular regimes viaconstitutional rather than military coups.Um amplo estudo sobre os governos da “maré rosa” na América Latina e as formações sociais subjacentes a eles, recolocou o debate do socialismo do século XXI. Se no período de 1990 a 2010 houve nova insurgência popular após o colapso do bloco soviético, ultimamente as forças progressistas são confrontadaspor uma reação de “baixa intensidade” do poderio combinado das burguesias locais e imperiais. A hegemonia dos EUA enfrenta renovado antineoliberalismo,mas agora ataca os regimes populares mediante golpes constitucionais, ao invés de militares

The effect of the fastener of different configuration composite panels on failure analysis

This study presents the effect of the stacking sequence and fiber orientation on a composite sandwich panel subjected to static in-plane bolt loading. Six plates were constructed with laminates of unidirectional carbon fiber and cross ply weaves of fiberglass. The orientations that were examined included 0, +/- 45, and 90 degrees. Half of the plates had fiberglass lamina on the outside of the laminate while the other three plates had the carbon fiber on the outside. Experimental and analytical tests were performed to determine the best orientations and stacking sequence. For the numerical analysis, plates with fibers oriented at +/- 45 degrees showed the highest strength. The experimental data also showed high strengths for the +/- 45 degree plates. However the experimental data also showed high strengths for the 90 degree laminate but with very high displacements. These high displacements would not allow the joint to maintain its relative position to the adjacent part. The discrepancy between the strength of the FEA models and the experimental data is attributed to inaccurate strength properties. The effect of in situ strength and compression strength was found to have a significant effect on the accuracy of the FEA solution. Good correlation was found between the FEA and experimental data in predicting the trend of the stiffness of the plates

Symplectic and Semiclassical Aspects of the Schl\"afli Identity

The Schl\"afli identity, which is important in Regge calculus and loop quantum gravity, is examined from a symplectic and semiclassical standpoint in the special case of flat, 3-dimensional space. In this case a proof is given, based on symplectic geometry. A series of symplectic and Lagrangian manifolds related to the Schl\"afli identity, including several versions of a Lagrangian manifold of tetrahedra, are discussed. Semiclassical interpretations of the various steps are provided. Possible generalizations to 3-dimensional spaces of constant (nonzero) curvature, involving Poisson-Lie groups and q-deformed spin networks, are discussed.Comment: 40 pages, 8 figure