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Simulated spacecraft water recovery wastewater feed streams were purified with a three-stage vacuum rotary distillation processor (TVRD) during a series of tests conducted to evaluate the operation of this technology. The TVRD was developed to efficiently reclaim potable water from urine in microgravity by NIICHIMMASH (Moscow, Russia). A prototype was evaluated at the Honeywell Space Water Reclamation test lab, where a special test setup was assembled to evaluate the performance of the TVRD. This paper discusses the TVRD technology, test description, test results, and performance analysis. Tests were conducted using four streams of wastewater: pretreated human urine, bioprocessor effluent, reverse osmosis brine ersatz, and deionized water. The testing demonstrated that greater than 90 percent water recovery can be reached with production rates of 2.2 to 2.9 kg/hr (4.84 to 6.30 lb/hr).

It’s a common practice to use different kinds tools to aid in the development and verification of modern safety critical avionics systems. These tools play a key role in avionics engineering and used in all project phases: requirements development, software design, source code development, integration, configuration management, and verification. Tools assist to analyze and improve system safety by automation of some of the activities which if performed manually and are therefore prone to human error. However, incorrect functioning of a tool can have negative impact on the safety and performance of the Safety Critical system. Hence, tools are proposed to be qualified whenever any of the design assurance process(es) described in RTCA/DO-178C or RTCA/DO-254 are eliminated, reduced, or automated using the tool unless the output of the tool is verified manually. Qualification of the tool gives confidence in the tool functionality.

Atmospheric Neutron Single Event Effects (SEE) are widely known to cause failures in all electronic hardware, and cause proportionately more failures in avionics equipment due to the use altitude. In digital systems it is easy to show how SEE can contribute several orders of magnitude more faults than random (hard) failures. Unfortunately, current avionics Safety assessment methods do not require consideration of faults from SEE. AVSI SEE Task Group (Aerospace Vehicle Systems Institute Committee #72, on Mitigating Radiation Effects in Avionics) is currently coordinating development of an atmospheric Neutron Single Event Effects (SEE) Analysis method. This analysis method is a work in progress, in close collaboration with SAE S-18 and WG-63 Committees (Airplane Safety Assessment Committee). The intent is to include this method as part of current revisions to ARP4761 (Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne Systems and Equipment).

Natural atmospheric radiation effects have been recognized in recent years as key safety and reliability concerns for avionics systems. Atmospheric radiation may cause Single Event Effects (SEE) in electronics. The resulting Single Event Effects can cause various fault conditions, including hazardous misleading information and system effects in avionics equipment. As technology trends continue to achieve higher densities and lower voltages, semiconductor devices are becoming more susceptible to atmospheric radiation effects. To ensure a system meets all its safety and reliability requirements, SEE induced upsets and potential system failures need to be considered. The purpose of this paper is to describe a process to incorporate the SEE analysis into the development like-cycle. Background on the atmospheric radiation phenomenon and the resulting single event effects, including single event upset (SEU) and latch up conditions is provided.

The operating environment of aircraft causes accumulation and build-up of contamination on both the narrowest passages of the ECS (Environmental Control System) i.e: the heat exchangers. Accumulated contamination may lead to reduction of performance over time, and in some case to failures causing AOG (Aircraft on Ground), customer dissatisfaction and elevated repair costs. Airframers/airlines eschew fixed maintenance cleaning intervals because of the high cost of removing and cleaning these devices preferring instead to rely on on-condition maintenance. In addition, on-wing cleaning is t impractical because of installation constrains. Hence, it is desirable to have a contamination monitoring that could alert the maintenance crew in advance to prepare and minimize disruption when contamination levels exceed acceptable thresholds. Two methods are proposed to achieve this task, The effectiveness of these methods are demonstrated using analytical and computational tools.

The issues of active vs. passive means of power quality improvement in aerospace applications are addressed. The concept of nonlinear load, i.e., the relationship between the current harmonics and system power factor has been reviewed. Both passive and active means of harmonic minimization are discussed, including resonance issues associated with passive networks and presenting an active rectifier switched in a Space Vector (SV) Pulse Width Modulation (PWM) manner. The analysis of power quality in aerospace applications is presented, together with the industry governing standards. Results of case studies are given, using Saber hierarchical tools for the system analysis. Both simulation and experimental results are provided, demonstrating power quality improvements in several aerospace applications.