Measurements of radiation exposure in civil aircraft

The radiation exposures on 12 flights of German airlines were measured with an active dosemeter based on two silicon semiconductors. The dependence on the date, altitude and route of the flights was studied. Measured dose rates and preliminary dose equivalent rates of the individual flights are given and compared with model calculations.     

Designing space vehicle shields for meteoroid protection: A new analysis

Dual-layer meteroid shields consisting of sacrificial bumper plates spaced some distance outboard from the vehicle hull are the most effective structures yet conceived for protecting space vehicles from supervelocity meteroid impacts. This paper presents a new analysis for designing dual-layer shields. The analysis is based upon energy and momentum conservation, fundamental electromagnetic radiation physics, and observation of results from extensive experimental impact investigations conducted at relatively low velocities (near 7 km/s). One important conclusion is that most of the kinetic energy of a meteoroid striking a dual-layer shield is expended as radiation at the stagnation zone on the face plate of the underlying structure. The analysis includes systematic procedures to evaluate the response of shield designs for a given impact threat. Similar applications of the analysis can be used to support a mathematically rigorous procedure for optimum shield design. The research described here supported the Halley Intercept Mission Project at the Jet Propulsion Laboratory, C.I.T., under Contract No. NAS 7–100, sponsored by the National Aeronautics and Space Administration.     

Lunar precursor missions for human exploration of Mars--III: studies of system reliability and maintenance

Discussions of future human expeditions into the solar system generally focus on whether the next explorers ought to go to the Moon or to Mars. The only mission scenario developed in any detail within NASA is an expedition to Mars with a 500-day stay at the surface. The technological capabilities and the operational experience base required for such a mission do not now exist nor has any self-consistent program plan been proposed to acquire them. In particular, the lack of an Abort-to-Earth capability implies that critical mission systems must perform reliably for 3 years or must be maintainable and repairable by the crew. As has been previously argued, a well-planned program of human exploration of the Moon would provide a context within which to develop the appropriate technologies because a lunar expedition incorporates many of the operational elements of a Mars expedition. Initial lunar expeditions can be carried out at scales consistent with the current experience base but can be expanded in any or all operational phases to produce an experience base necessary to successfully and safely conduct human exploration of Mars.     

Recent NASA research accomplishments aboard the ISS

The activation of the US Laboratory Module "Destiny" on the International Space Station (ISS) in February 2001 launched a new era in microgravity research. Destiny provides the environment to conduct long-term microgravity research utilizing human intervention to assess, report, and modify experiments real time. As the only available pressurized space platform, ISS maximizes today's scientific resources and substantially increases the opportunity to obtain much longed-for answers on the effects of microgravity and long-term exposure to space. In addition, it evokes unexpected questions and results while experiments are still being conducted, affording time for changes and further investigation. While building and outfitting the ISS is the main priority during the current ISS assembly phase, seven different space station crews have already spent more than 2000 crew hours on approximately 80 scientific investigations, technology development activities, and educational demonstrations.     

Precipitating Protons and Their Role in Ionization of the Polar Ionosphere

Spatial distributions of the electron density in the latitude range 60°–90° N were calculated on the basis of a physical model of the E and lower Fregions of the high-latitude ionosphere using statistical models of auroral proton and electron precipitation. It is shown that precipitating protons can play the key role in the ionization of the Eregion in the dusk and midnight sectors of the auroral oval. However, quantitative estimates of the contribution of protons to the ionization depend on the used statistical models of electron precipitation. Comparison of the electron density profiles calculated for two incoherent scatter radars, EISCAT (Tromsö) and ESR (Svalbard), for simultaneous precipitation of electrons and protons and for electron precipitation only show that the influence of protons is the most significant in the dusk sector over the EISCAT radar and in the midnight sector over the ESR radar. The results presented indicate the need to take protons into account when radar data are used to derive precipitating electron spectra.     

Review and analysis of the register of space objects

Parties to the Registration Convention are committed to providing the United Nations with certain information about objects they launch into space. This report describes the categories of information required, outlines the inadequacies of the present Register and suggests modifications.     

Surreal estate: addressing the issue of ‘Immovable Property Rights on the Moon’

At a time when scientific and commercial interest in the Moon is being reinvigorated it is becoming fashionable for ordinary individuals to ‘buy’ plots on the lunar surface, with the ‘vendors’ arguing that an absence of specific prohibition of individual private activity in space makes such action legal. It is therefore time for the legal community to address this situation by investigating just how legal such activity is—and bringing their findings to the attention of governments. This can be done through an examination of the relationship between national law and international space law, of the provisions of international space law—especially Article 2 of the Outer Space Treaty—and by answering any claims to private ownership of immovable property. Aside from the fact that individuals appear to be being duped, the pursuit of property claims on the Moon could impede future activities aimed at benefiting society.     

The Suess-Urey mission (return of solar matter to Earth)

The Suess-Urey (S-U) mission has been proposed as a NASA Discovery mission to return samples of matter from the Sun to the Earth for isotopic and chemical analyses in terrestrial laboratories to provide a major improvement in our knowledge of the average chemical and isotopic composition of the solar system. The S-U spacecraft and sample return capsule will be placed in a halo orbit around the L1 Sun-Earth libration point for two years to collect solar wind ions which implant into large passive collectors made of ultra-pure materials. Constant Spacecraft-Sun-Earth geometries enable simple spin stabilized attitude control, simple passive thermal control, and a fixed medium gain antenna. Low data requirements and the safety of a Sun-pointed spinner, result in extremely low mission operations costs.     

Erratum to: Determination of the Probability of Collision of Near-Earth Space Objects Taking into Account Form and Orientation

Cosmic Research - An Erratum to this paper has been published: https://doi.org/10.1134/S0010952521120030