7 research outputs found

    Jupiter radiation test levels and their expected impact on an encounter mission

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    The upper limit, of electron and proton fluences for a thermoelectric outer planet spacecraft mission in a near-Jupiter environment, for use as radiation design restraints, were extracted from a model of the Jovian trapped radiation belts. Considerations of radiation effects in semiconductor devices were employed to construct simplified radiation test levels based on the design restraints. Corresponding levels, based on the nominal belt models, are one to three orders of magnitude smaller. In terms of expected radiation-induced degradation in semiconductor devices, an encounter with an environment as severe as the design restraints would require hardening the system in order to guarantee high reliability. On the other hand, the nominal levels would only necessitate care in the selection of components and the avoidance of certain semiconductor components

    The effect of 1 to 5 keV electrons on the reproductive integrity of microorganisms

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    Microorganisms were exposed to simulated space environment in order to assess the effect of electrons in the energy range 1 to 5 keV on their colony-forming ability. The test system consisted of an electron gun and power supply, a dosimetry subsystem, and a vacuum subsystem. The system was capable of current densities ranging from 0.1 nA/sq cm to 5 micro A/sq cm on a 25 sq on target and an ultimate vacuum of 0.0006 N/sq m (0.000004 torr). The results of the experimental program show a significant reduction in microbial reproductive integrity

    A proposed new policy for planetary protection

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    A critical review of the present policy was conducted with emphasis on its application to future planetary exploration. The probable impact of recent data on the implementation of the present policy was also assessed. The existing policy and its implementation were found to: be excessive for certain missions (e.g., Voyager), neglect the contamination hazard posed by the bulk constituent organics of spacecraft, be ambiguous for certain missions (e.g., Pioneer Venus), and treat all extraterrestrial sample return missions alike. The major features of the proposed policy are planet/mission combinations, a qualitative top level statement, and implementation by exception rather than rule. The concept of planet/mission categories permits the imposition of requirements according to both biological interest in the target planet and the relative contamination hazard of the mission type

    Particle adhesion to surfaces under vacuum

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    Microbial certification of the MER spacecraft

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    We conclude in this paper that a combination of Dry Heat Microbrial Reduction and control measures during complex mechanical assembly processes can result in a total spore bioburden that meets requirements

    COSPAR Panel on Planetary Protection Colloquium, Bern, Switzerland, September 2015 (Meeting Reports)

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    The COSPAR Planetary Protection Policy describes requirements for different planetary protection categories depending on the type of mission, the target body and the type of scientific investigations [1]. Updating the COSPAR Planetary Protection Policy is an iterative process that involves the scientific community. This process is based on new scientific discoveries, new understanding of scientific observations, or, responds to needs identified to prepare future space missions. In consultation with the COSPAR Scientific Commissions B (Space Studies of the Earth-Moon System, Planets, and Small Bodies of the Solar System) and F (Life Sciences as Related to Space), the COSPAR Panel on Planetary Protection organised a colloquium at the International Space Science Institute (ISSI) in Bern, Switzerland, in September 2015, to discuss two pertinent topics: - Icy moon sample return planetary protection requirements - Mars Special Regions planetary protection requirements These two topics were addressed in two separate sessions. The recommendations described in this report are based on discussions in the course of the colloquium and reflect a consensus of the colloquium attendees that participated in one or both separate sessions. Any opinions, conclusions, or recommendations expressed in this report are those of the attendee(s) and do not necessarily reflect the views of the organisations that provided support for their participation
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