The Experts below are selected from a list of 23514 Experts worldwide ranked by ideXlab platform
Ian A. Crawford - One of the best experts on this subject based on the ideXlab platform.
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Direct Exoplanet Investigation using Interstellar Space Probes
arXiv: Earth and Planetary Astrophysics, 2017Co-Authors: Ian A. CrawfordAbstract:Experience in exploring our own solar system has shown that direct investigation of planetary bodies using Space Probes invariably yields scientific knowledge not otherwise obtainable. In the case of exoplanets, such direct investigation may be required to confirm inferences made by astronomical observations, especially with regard to planetary interiors, surface processes, geological evolution, and possible biology. This will necessitate transporting sophisticated scientific instruments across interstellar Space, and some proposed methods for achieving this with flight-times measured in decades are reviewed. It is concluded that, with the possible exception of very lightweight (and thus scientifically limited) Probes accelerated to velocities of ~0.1c with powerful Earth-based lasers, achieving such a capability may have to wait until the development of a Space-based civilization capable of leveraging the material and energy resources of the solar system.
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A comment on "the far future of exoplanet direct characterization"--the case for interstellar Space Probes.
Astrobiology, 2010Co-Authors: Ian A. CrawfordAbstract:Abstract Following on from ideas presented in a recent paper by Schneider et al. on “The Far Future of Exoplanet Direct Characterization,” I argue that they have exaggerated the technical obstacles to performing such “direct characterization” by means of fast (order 0.1c) interstellar Space Probes. A brief summary of rapid interstellar Spaceflight concepts that may be found in the literature is presented. I argue that the presence of interstellar dust grains, while certainly something that will need to be allowed for in interstellar vehicle design, is unlikely to be the kind of showstopper suggested by Schneider et al. Astrobiology as a discipline would be a major beneficiary of developing an interstellar Spaceflight capability, albeit in the longer term, and I argue that astrobiologists should keep an open mind to the possibilities. Key Words: Far future missions—Interstellar Space travel. Astrobiology 10, 853–856.
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a comment on the far future of exoplanet direct characterization the case for interstellar Space Probes
arXiv: Instrumentation and Methods for Astrophysics, 2010Co-Authors: Ian A. CrawfordAbstract:Following on from ideas presented in a recent paper by Schneider et al. (2010) on "The Far Future of Exoplanet Direct Characterization", I argue that they have exaggerated the technical obstacles to performing such 'direct characterization' by means of fast (order 0.1c) interstellar Space Probes. A brief summary of rapid interstellar Spaceflight concepts that may be found in the literature is presented. I argue that the presence of interstellar dust grains, while certainly something which will need to be allowed for in interstellar vehicle design, is unlikely to be the kind of 'show stopper' suggested by Schneider et al. Astrobiology as a discipline would be a major beneficiary of developing an interstellar Spaceflight capability, albeit in the longer term, and I argue that astrobiologists should keep an open mind to the possibilities.
Veerle J. Sterken - One of the best experts on this subject based on the ideXlab platform.
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Interplanetary Dust, Meteoroids, Meteors and Meteorites
Space Science Reviews, 2019Co-Authors: Detlef Koschny, Jérémie Lasue, Anny Chantal Levasseur-regourd, George J. Flynn, Rachel H. Soja, Cecile Engrand, David Malaspina, Tomoki Nakamura, Andrew R. Poppe, Veerle J. SterkenAbstract:Interplanetary dust particles and meteoroids mostly originate from comets and asteroids. Understanding their distribution in the Solar system, their dynamical behavior and their properties, sheds light on the current state and the dynamical behavior of the Solar system. Dust particles can endanger Earth-orbiting satellites and deep-Space Probes, and a good understanding of the spatial density and velocity distribution of dust and meteoroids in the Solar system is important for designing proper Spacecraft shielding. The study of interplanetary dust and meteoroids provides clues to the formation of the Solar system. Particles having formed 4.5 billion years ago can survive planetary accretion and those that survived until now did not evolve significantly since then. Meteoroids and interplanetary dust can be observed by measuring the intensity and polarization of the zodiacal light, by observing meteors entering the Earth’s atmosphere, by collecting them in the upper atmosphere, polar ices and snow, and by detecting them with in-situ detectors on Space Probes.
Detlef Koschny - One of the best experts on this subject based on the ideXlab platform.
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Interplanetary Dust, Meteoroids, Meteors and Meteorites
Space Science Reviews, 2019Co-Authors: Detlef Koschny, Jérémie Lasue, Anny Chantal Levasseur-regourd, George J. Flynn, Rachel H. Soja, Cecile Engrand, David Malaspina, Tomoki Nakamura, Andrew R. Poppe, Veerle J. SterkenAbstract:Interplanetary dust particles and meteoroids mostly originate from comets and asteroids. Understanding their distribution in the Solar system, their dynamical behavior and their properties, sheds light on the current state and the dynamical behavior of the Solar system. Dust particles can endanger Earth-orbiting satellites and deep-Space Probes, and a good understanding of the spatial density and velocity distribution of dust and meteoroids in the Solar system is important for designing proper Spacecraft shielding. The study of interplanetary dust and meteoroids provides clues to the formation of the Solar system. Particles having formed 4.5 billion years ago can survive planetary accretion and those that survived until now did not evolve significantly since then. Meteoroids and interplanetary dust can be observed by measuring the intensity and polarization of the zodiacal light, by observing meteors entering the Earth’s atmosphere, by collecting them in the upper atmosphere, polar ices and snow, and by detecting them with in-situ detectors on Space Probes.
Richard Wilson - One of the best experts on this subject based on the ideXlab platform.
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risk of nuclear powered Space Probes
Reliability Engineering & System Safety, 2004Co-Authors: William E Kastenberg, Richard WilsonAbstract:Abstract In recent years, three Probes have been sent into outer Space: Galileo, Ulysses and Cassini. Each has used for its electricity power source, a radioactive thermoelectric generator (RTG), heated by a source of plutonium 238. Cassini, launched in October 1997, will reach its scientific objective in late June or early July 2004, concurrent with PSAM7. The authors of this paper had the privilege of providing the final review of the Cassini safety assessments for the Office of Science and Technology of the President, before final approval by the President of the United States, as required by law and international treaty, before the launch of any nuclear device into Space. In this paper, we will discuss the risk analysis carried out jointly by NASA and DOE and our assessment of their results. Since the United States has established a new initiative for Space exploration using a nuclear fission device for exploration of the icy moons of Jupiter (JIMO), we believe the JIMO project can benefit from a critical review of the experience gained by past projects using RTGs, and in particular identification of those aspects which make the risk estimates plausible to the layman. There are several scenarios for possible adverse effects on public health. The probabilities for each scenario must be added to form a number for the overall risk. The probability of each scenario is a product of two basic terms: the probability of release of plutonium and the probability of an individual being hurt by the release. It is evident that the probabilities for the two terms are truly independent. For example, there is reason to believe that the probability of the Space probe hitting the earth in a failed ‘swing by’ only has a connection with the stochastic probability of developing lung cancer by the amount of plutonium evaporated and not by the mechanism of cancer induction. Each probability is on the order of one in a million. Then it is easy to understand why the risk to an individual of a ‘swing by’ is less than one in 1011 years, although the more complex NASA-DOE calculations, which allow for a reduction in the plutonium release for many possible reentry scenarios, puts it a factor of 50 smaller. We also comment on the procedures used for calculating the probabilities and consequences of these scenarios, on presenting these calculations to the public, on errors in various public comments on the Cassini Environmental Impact Statement, and on the comparative risks from RTGs and small nuclear reactors.
Juan A. Lenero-bardallo - One of the best experts on this subject based on the ideXlab platform.
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A Miniaturized Two-Axis Ultra Low Latency and Low-Power Sun Sensor for Attitude Determination of Micro Space Probes
IEEE Transactions on Circuits and Systems I: Regular Papers, 2018Co-Authors: Lukasz Farian, Philipp Hafliger, Juan A. Lenero-bardalloAbstract:This paper describes design, fabrication process, and comprehensive experimental results of a first prototype two-axis miniaturized spiking sun sensor. The sun sensor is a fusion of analog and digital sensor types, such that it takes advantage of spatial selectivity of digital sensors, and is not limited by the global frame rate as in analog sun sensors. It is composed of spiking pixels, and uses a novel Time-to-First-n-Spikes with time-out readout mode to reduce bandwidth consumption and post-processing computation. A thin glass lid with a metal deposited pattern serves as a mask projecting a light pattern onto the sensor. The sun sensor is able to extract a profile of the incident light in the form of time-stamped events. Its latency depends on light intensity, and for medium radiance conditions is equal to $ {88~\mu s}$ . The sun sensor consumes $ {6.3~\mu W}$ in normal operation, and has a precision of 0.98°, and a field of view of 144°. The high temporal resolution, low power consumption, and small QFN64 package make this sun sensor suitable for Space probe and sounding rocket applications, where low temporal latency and payload size are essential. This sun sensor is designed to be employed in the sounding rocket attitude determination system as part of the 4DSpace research initiative to study ionospheric plasma disturbances.
