982 research outputs found
Interoperability Trends in Extravehicular Activity (EVA) Space Operations for the 21st Century
No other space operations in the 21 st century more comprehensively embody the challenges and dependencies of interoperability than EVA. This discipline is already functioning at an W1paralleled level of interagency, inter-organizational and international cooperation. This trend will only increase as space programs endeavor to expand in the face of shrinking budgets. Among the topics examined in this paper are hardware-oriented issues. Differences in design standards among various space participants dictate differences in the EVA tools that must be manufactured, flown and maintained on-orbit. Presently only two types of functional space suits exist in the world. However, three versions of functional airlocks are in operation. Of the three airlocks, only the International Space Station (ISS) Joint Airlock can accommodate both types of suits. Due to functional differences in the suits, completely different operating protocols are required for each. Should additional space suit or airlock designs become available, the complexity will increase. The lessons learned as a result of designing and operating within such a system are explored. This paper also examines the non-hardware challenges presented by interoperability for a discipline that is as uniquely dependent upon the individual as EVA. Operation of space suits (essentially single-person spacecrafts) by persons whose native language is not that of the suits' designers is explored. The intricacies of shared mission planning, shared control and shared execution of joint EVA's are explained. For example, once ISS is fully functional, the potential exists for two crewmembers of different nationality to be wearing suits manufactured and controlled by a third nation, while operating within an airlock manufactured and controlled by a fourth nation, in an effort to perform tasks upon hardware belonging to a fifth nation. Everything from training issues, to procedures development and writing, to real-time operations is addressed. Finally, this paper looks to the management challenges presented by interoperability in general. With budgets being reduced among all space-faring nations, the need to expand cooperation in the highly expensive field of human space operations is only going to intensify. The question facing management is not if the trend toward interoperation will continue, but how to best facilitate its doing so. Real-world EVA interoperability experience throughout the ShuttlelMir and ISS Programs is discussed to illustrate the challenges an
Department of Defense Technology Transfer -Civilian Uses of Military Know-How
President Nixon, in his March 16, 1972 Message to Congress, challenged the nation to harness science and technology to strengthen our economy and improve the quality of life in the U. S. A portion of his statement addressed the issue of using federal R & D laboratories to assist in solving local and state problems.
In June of the same year, over 200 leaders from all levels of government, industry and academia met in Harrisburg, Pennsylvania for the National Conference on Inter^ governmental Science and Technology Policy. The goal of the Conference was to identify actions essential for effective use of public and private science and technological resources to aid harried state and local officials in providing services at an acceptable level of cost. One of the principal resolutions passed by the Conference called for the use of federal laboratories to solve local problems. This Conference was the forerunner of numerous subsequent studies by such agencies as 0MB and NSF, plus numerous articles, all calling for the application of federal technology toward the solution of civilian problems
Public Law and the Military Commander: Responsibility and Authority
Too often the commander overly concerns himself with the secondary and tertiary rules and regulations of middle management and overlooks the primary authority on which to base his actions and responsibilities—the PUBLIC LAW
Impulse approximation in the n p --> d pi^0 reaction reexamined
The impulse approximation (one-body operator) in the n p --> d pi^0 reaction
is reexamined with emphasis on the issues of reducibility and recoil
corrections. An inconsistency when one pion exchange is included in the
production operator is demonstrated and then resolved via the introduction of
"wave function corrections" which nearly vanish for static nucleon propagators.
Inclusion of the recoil corrections to the nucleon propagators is found to
change the magnitude and sign of the impulse production amplitude, worsening
agreement with the experimental cross section by approximately 30%. A cutoff is
used to account for the phenomenological nature of the external wave functions,
and is found to have a significant impact up to approximately 2.5 GeV.Comment: Published versio
The Problem of the "Prebiotic and Never Born Proteins"
It has been argued that the limited set of proteins used by life as we know
it could not have arisen by the process of Darwinian selection from all
possible proteins. This probabilistic argument has a number of implicit
assumptions that may not be warranted. A variety of considerations are
presented to show that the number of amino-acid sequences that need have been
sampled during the evolution of proteins is far smaller than assumed by the
argument.Comment: 14 Pages; International Journal of Astrobiology / FirstView Article /
October 2012, pp 1
The Inclusive-Exclusive Connection and the Neutron Negative Central Charge Density
We find an interpretation of the recent finding that the central charge
density of the neutron is negative by using models of generalized parton
distributions at zero skewness to relate the behavior of deep inelastic
scattering quark distributions, evaluated at large values of Bjorken x, to the
transverse charge density evaluated at small distances. The key physical input
of these models is the Drell-Yan-West relation We find that the d quarks
dominate the neutron structure function for large values of Bjorken x, where
the large longitudinal momentum of the struck quark has a significant impact on
determining the center-of-momentum of the system, and thus the "center" of the
nucleon in the transverse position plane.Comment: 17 pages, 8 figures. Text of an invited talk presented by G. A.
Miller at the 2008 Division of Nuclear Physics Meeting in Oakland. Prepared
for Int. Journ. Mod. Phys.
Proton Electromagnetic Form Factor Ratios at Low Q^2
We study the ratio of the proton at very small
values of . Radii commonly associated with these form factors are not
moments of charge or magnetization densities. We show that the form factor
is correctly interpretable as the two-dimensional Fourier transformation
of a magnetization density. A relationship between the measurable ratio and
moments of true charge and magnetization densities is derived. We find that
existing measurements show that the magnetization density extends further than
the charge density, in contrast with expectations based on the measured
reduction of as increases.Comment: 4 pages 3 figures We have corrected references, figures and some
typographical error
The onsite manufacture of propellant oxygen from lunar resources
The Aerojet carbothermal process for the manufacture of oxygen from lunar materials has three essential steps: the reduction of silicate with methane to form carbon monoxide and hydrogen; the reduction of carbon monoxide with hydrogen to form methane and water; and the electrolysis of water to form hydrogen and oxygen. The reactions and the overall process are shown. It is shown with laboratory experimentation that the carbothermal process is feasible. Natural silicates can be reduced with carbon or methane. The important products are carbon monoxide, metal, and slag. The carbon monoxide can be completely reduced to form methane and water. The water can be electrolyzed to produce hydrogen and oxygen. A preliminary engineering study shows that the operation of plants using this process for the manufacture of propellant oxygen has a large economic advantage when the cost of the plant and its operation is compared to the cost of delivering oxygen from Earth
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