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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.

Thin films continue to play an ever-increasing role in high performance structures for space exploration. Membrane structures have been developed or envisioned for such applications as scientific balloons, deep space antennas, Earth radiometers, radars, concentrators, telescopes, sun shields, solar sails, solar arrays, spacecraft booms, and planetary surface habitats. Inflatable membrane structures can have very high packaging efficiencies, are easy to construct at remote locations and are lightweight because pressure differences provide structural stabilization without the need for rigid supports or internal framework. Recent proposals have suggested construction of an inflatable greenhouse from transparent polymer films for Mars surface operations. This paper reports on the progress to examine the effects of mechanical loading on the rates of photodegradation in transparent polymer films exposed to simulated Mars ultraviolet radiation.