Shuttle/ISS EMU Failure History and the Impact on Advanced EMU Portable Life Support System (PLSS) Design

As the Shuttle/ISS EMU Program exceeds 35 years in duration and is still supporting the needs of the International Space Station (ISS), a critical benefit of such a long running program with thorough documentation of system and component failures is the ability to study and learn from those failures when considering the design of the next generation space suit. Study of the subject failure history leads to changes in the Advanced EMU Portable Life Support System (PLSS) schematic, selected component technologies, as well as the planned manner of ground testing. This paper reviews the Shuttle/ISS EMU failure history and discusses the implications to the AEMU PLSS

Shuttle/ISS EMU Failure History and the Impact on Advanced EMU PLSS Design

As the Shuttle/ISS EMU Program exceeds 30 years in duration and is still successfully supporting the needs of the International Space Station (ISS), a critical benefit of such a long running program with thorough documentation of system and component failures is the ability to study and learn from those failures when considering the design of the next generation space suit. Study of the subject failure history leads to changes in the Advanced EMU Portable Life Support System (PLSS) schematic, selected component technologies, as well as the planned manner of ground testing. This paper reviews the Shuttle/ISS EMU failure history and discusses the implications to the AEMU PLSS

Blackwell's ordering and public information

We characterize a precise comparative static on welfare and the amount of public information in an economy under uncertainty. Results dating to Hirshleifer (1971) have suggested that information can have negative value in such a setting, but counterexamples using competitive equilibrium outcomes have suppressed general results to this effect. We show that under the solution concept of implementable allocations, the negative relationship between more public information in the sense of Blackwell and welfare is fully general. Furthermore, Blackwell's ranking is necessary as well as sufficient to obtain our ranking, and hence ours provides an equivalent characterization of his ordering

What is wrong with consumerism

Contemporary consumerism is frequently the target of criticisms by intellectuals, academics, religious spokesmen and commentators. Five of the more common of these criticisms are selected for analysis and examination; these being (a) the need criticism (b) the materialism criticism (c) the addiction criticism (d) the selfishness criticism, and (e) the irrationality criticism. Each is then shown either to be misconceived or to lack empirical support

Conservation evo-devo: preserving biodiversity by understanding its origins

Unprecedented rates of species extinction increase the urgency for effective conservation biology management practices. Thus, any improvements in practice are vital and we suggest that conservation can be enhanced through recent advances in evolutionary biology, specifically advances put forward by evolutionary developmental biology (i.e., evo-devo). There are strong overlapping conceptual links between conservation and evo-devo whereby both fields focus on evolutionary potential. In particular, benefits to conservation can be derived from some of the main areas of evo-devo research, namely phenotypic plasticity, modularity and integration, and mechanistic investigations of the precise developmental and genetic processes that determine phenotypes. Using examples we outline how evo-devo can expand into conservation biology, an opportunity which holds great promise for advancing both fields

Let them burn money: making elections more informative

A standard election in which each voter chooses a single alternative permits voters little scope to express the intensity of their preferences. Allowing more complex statements of preferences may not alleviate the problem if voters behave strategically, as only certain statements are credible. I consider the implications of allowing voters to burn money as part of the voting procedure. In an environment with two alternatives and voters with interdependent values, I find necessary and sufficient conditions for all choice functions that are minimally responsive to voter preferences to be implementable with money burning. Furthermore, I show that any choice rule that treats exante identical voters symmetrically can be implemented with an arbitrarily small amount of money burnt per voter as the set of voters is replicated. Thus, for a large electorate, the informational gains of money burning can be reaped at virtually no social cost

Development Specification for the Portable Life Support System (PLSS) Thermal Loop Pump

The AEMU Thermal Loop Pump Development Specification establishes the requirements for design, performance, and testing of the Water Pump as part of the Thermal System of the Advanced Portable Life Support System (PLSS). It is envisioned that the Thermal Loop Pump is a positive displacement pump that provides a repeatable volume of flow against a given range of back-pressures provided by the various applications. The intention is to operate the pump at a fixed speed for the given application. The primary system is made up of two identical and redundant pumps of which only one is in operation at given time. The Auxiliary Loop Pump is an identical pump design to the primary pumps but is operated at half the flow rate. Inlet positive pressure to the pumps is provided by the upstream Flexible Supply Assembly (FSA-431 and FSA-531) which are physically located inside the suit volume and pressurized by suit pressure. An integrated relief valve, placed in parallel to the pump's inlet and outlet protects the pump and loop from over-pressurization. An integrated course filter is placed upstream of the pump's inlet to provide filtration and prevent potential debris from damaging the pump

Design and Testing of Suit Regulator Test Rigs

The next generation space suit requires additional capabilities for controlling and adjusting internal pressure compared to that of historical designs. Next generation suit pressures will range from slight pressure, for astronaut prebreathe comfort, to hyperbaric pressure levels for emergency medical treatment of decompression sickness. In order to test these regulators through-out their development life cycle, novel automated test rigs are being developed. This paper addresses the design philosophy, performance requirements, physical implementation, and test results with various units under test

Development Specification for the Feedwater Supply Assembly (FSA), FSA-431 with Integrated Auxiliary Feedwater Supply Assembly (AFSA), FSA-531

The FSA with Integrated Aux FSA Specification establishes the requirements for design, performance, and testing of the FSA-431/FSA-531 assembly in compliance with CTSD-ADV-780, Development Specification for the Advanced EMU (AEMU) Portable Life Support System (PLSS). This section contains the technical design and performance requirements for the integrated assembly of the Feedwater Supply Assembly and Auxiliary Feedwater Supply Assembly for the Advanced EVA Development Portable Life Support Subsystem (PLSS)