Neutral environment for space station

The results of studies to determine the contamination compatibility of the cross boom and dual keel Space Station configurations with attached payloads are presented. The approach was to define the 3-D configuration of the Space Station and calculate surface-to-surface view factors and solid angles between surfaces and points in an extensive point matrix around the Space Station via a modified TRASYS model. The molecular number column densities along specific experiment lines-of-sight on the cross boom generally meet JSC 30426 requirements. The deposition of contaminants on payload surfaces exceeds the JSC 30426 requirements. These model predictions require updating because of the impact on background brightness predictions. An increase of a factor of 2 to 10 in column densities would result in an unacceptable optical background

Payload/orbiter contamination control assessment support

The development and use is described of a basic contamination mathematical model of the shuttle orbiter which incorporates specific shuttle orbiter configurations and contamination sources. These configurations and sources were evaluated with respect to known shuttle orbiter operational surface characteristics and specific lines-of-sight which encompass the majority of viewing requirements for shuttle payloads. The results of these evaluations are presented as summary tables for each major source. In addition, contamination minimization studies were conducted and recommendations are made, where applicable, to support the shuttle orbiter design and operational planning for those sources which were identified to present a significant contamination threat

Contamination assessment for OSSA space station IOC payloads

The results are presented from a study for the Space Station Planners Group of the Office of Space Sciences and Applications. The objectives of the study are: (1) the development of contamination protection requirements for protection of Space Station attached payloads, serviced payloads and platforms; and (2) the determination of unknowns or major impacts requiring further assessment. The nature, sources, and quantitative properties of the external contaminants to be encountered on the Station are summarized. The OSSA payload contamination protection requirements provided by the payload program managers are reviewed and the level of contamination awareness among them is discussed. Preparation of revisions to the contamination protection requirements are detailed. The comparative impact of flying the Station at constant atmospheric density rather than constant altitude is assessed. The impact of the transverse boom configuration of the Station on contamination is also assessed. The contamination protection guidelines which OSSA should enforce during their development of payloads are summarized

Orbiter/payload contamination control assessment support

The development and integration of 16 payload bay liner filters into the existing shuttle/payload contamination evaluation (SPACE) computer program is discussed as well as an initial mission profile model. As part of the mission profile model, a thermal conversion program, a temperature cycling routine, a flexible plot routine and a mission simulation of orbital flight test 3 are presented

Payload/orbiter contamination control requirement study

A study was conducted to determine and quantify the expected particulate and molecular on-orbit contaminant environment for selected space shuttle payloads as a result of major shuttle orbiter contamination sources. Individual payload susceptibilities to contamination are reviewed. The risk of payload degradation is identified and preliminary recommendations are provided concerning the limiting factors which may depend on operational activities associated with the payload/orbiter interface or upon independent payload functional activities. A basic computer model of the space shuttle orbiter which includes a representative payload configuration is developed. The major orbiter contamination sources, locations, and flux characteristics based upon available data have been defined and modeled

Transitions in vortex skyrmion structures in superfluid 3^3He-A driven by an analogue of the zero-charge effect

In quantum electrodynamics, the zero-charge effect originates from the logarithmic dependence of the coupling constant in the action of the electromagnetic field on the ratio of the ultraviolet and infrared energy cutoffs. An analogue of this effect in Weyl superfluid $^3$He-A is the logarithmic divergence of the bending energy of the orbital anisotropy axis at low temperatures, where temperature plays the role of the infrared cutoff and the vector of the orbital anisotropy plays the role of the vector potential of the synthetic electromagnetic field for Weyl fermions. We calculate numerically the spatial distribution of the order parameter in rotating $^3$He-A as a function of temperature. At temperatures close to the superfluid transition, we observe formation of vortex skyrmions known as the double-quantum vortex and the vortex sheet. These structures include alternating circular and hyperbolic merons as a bound pair or a chain, respectively. As temperature lowers towards absolute zero, we find a continuous transition in the vortex structures towards a state where the vorticity is distributed in thin tubes around the circular merons. For the vortex sheet, we present a phase diagram of the transition in the temperature - angular velocity plane and calculations of the nuclear magnetic resonance response.Comment: 14 pages, 10 figure

Payload/orbiter contamination control requirement study, volume 2, exhibit A

The computer printout data generated during the Payload/Orbiter Contamination Control Requirement Study are presented. The computer listings of the input surface data matrices, the viewfactor data matrices, and the geometric relationship data matrices for the three orbiter/spacelab configurations analyzed in this study are given. These configurations have been broken up into the geometrical surfaces and nodes necessary to define the principal critical surfaces whether they are contaminant sources, experimental surfaces, or operational surfaces. A numbering scheme was established based upon nodal numbers that relates the various spacelab surfaces to a specific surface material or function. This numbering system was developed for the spacelab configurations such that future extension to a surface mapping capability could be developed as required

Experimental investigation of contamination prevention techniques to cryogenic surfaces on board orbiting spacecraft

Within the simulation limitations of on-orbit conditions, it was demonstrated that a helium purge system could be an effective method for reducing the incoming flux of contaminant species. Although a generalized purge system was employed in conjunction with basic telescope components, the simulation provided data that could be used for further modeling and design of a specific helium injection system. Experimental telescope pressures required for 90% attenuation appeared to be slightly higher (factor of 2 to 5). Cooling the helium purge gas and telescope components from 300 to 140 K had no measurable effect on stopping efficiency of a given mass flow of helium from the diffuse injector

Unenforceability

The patent doctrine of inequitable conduct—which allows a patent to be held unenforceable on the basis of misbehavior by the applicant during patent prosecution—has been the subject of intense criticism from the bench and bar alike. And yet to date there has been no systematic attempt to determine whether the doctrine is or is not working as theorized. This study fills that gap. We evaluate the performance of the inequitable conduct doctrine with a novel methodological approach: by empirically characterizing the differences between patents found unenforceable and several other types of patents (unlitigated, litigated, invalid, obvious, and underdisclosed), we use those differences to reveal the real-world impact of the inequitable conduct doctrine. We find that pat ents held unenforceable have clear hallmarks of risky prosecution behavior, such as longer pendency and fewer disclosures of prior art, as compared to all other types we studied. These results indicate that the doctrine is likely operating better than conven tional wisdom would suggest

Unenforceability

The patent doctrine of inequitable conduct—which allows a patent to be held unenforceable on the basis of misbehavior by the applicant during patent prosecution—has been the subject of intense criticism from the bench and bar alike. And yet to date there has been no systematic attempt to determine whether the doctrine is or is not working as theorized. This study fills that gap. We evaluate the performance of the inequitable conduct doctrine with a novel methodological approach: by empirically characterizing the differences between patents found unenforceable and several other types of patents (unlitigated, litigated, invalid, obvious, and underdisclosed), we use those differences to reveal the real-world impact of the inequitable conduct doctrine. We find that patents held unenforceable have clear hallmarks of risky prosecution behavior, such as longer pendency and fewer disclosures of prior art, as compared to all other types we studied. These results indicate that the doctrine is likely operating better than conventional wisdom would suggest