3,197 research outputs found
Papers of Rev. William C. McInnes, S.J.
No full textThis collection includes records of Fr. McInnes’ activities as President of Fairfield (1964-1973) as well as papers, scrapbooks, and photo albums documenting his personal interests, activities, and travels. Of particular note are the contents of a scrapbook maintained by Fr. McInnes devoted to letters and newspaper articles on the subject of student unrest at Fairfield between 1967 and 1970. The collection also includes biographical material on Fr. McInnes, including oral history transcripts and copies of obituary articles.https://digitalcommons.fairfield.edu/findingaids/1017/thumbnail.jp
Heliotropic dust rings for Earth climate engineering
No full textThis paper examines the concept of a Sun-pointing elliptical Earth ring comprised of dust grains to offset global warming. A new family of non-Keplerian periodic orbits, under the effects of solar radiation pressure and the Earth's J(2) oblateness perturbation, is used to increase the lifetime of the passive cloud of particles and, thus, increase the efficiency of this geoengineering strategy. An analytical model is used to predict the orbit evolution of the dust ring due to solar-radiation pressure and the J(2) effect. The attenuation of the solar radiation can then be calculated from the ring model. In comparison to circular orbits, eccentric orbits yield a more stable environment for small grain sizes and therefore achieve higher efficiencies when the orbit decay of the material is considered. Moreover, the novel orbital dynamics experienced by high area-to-mass ratio objects, influenced by solar radiation pressure and the J(2) effect, ensure the ring will maintain a permanent heliotropic shape, with dust spending the largest portion of time on the Sun facing side of the orbit. It is envisaged that small dust grains can be released from a circular generator orbit with an initial impulse to enter an eccentric orbit with Sun-facing apogee. Finally, a lowest estimate of 1 x 10(12) kg of material is computed as the total mass required to offset the effects of global warming
Mcinnes, D C, VX16404
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/403520Surname: MCINNES. Given Name(s) or Initials: D C. Military Service Number or Last Known Location: VX16404. Missing, Wounded and Prisoner of War Enquiry Card Index Number: 4381.224901
Item: [2016.0049.35813] "Mcinnes, D C, VX16404
Orbit design for future SpaceChip swarm missions in a planetary atmosphere
No full textThe effect of solar radiation pressure and atmospheric drag on the orbital dynamics of satellites-on-a-chip (SpaceChips) is exploited to design equatorial long-lived orbits about the oblate Earth. The orbit energy gain due to asymmetric solar radiation pressure, considering the Earth's shadow, is used to balance the energy loss due to atmospheric drag. Future missions for a swarm of SpaceChips are proposed, where a number of small devices are released from a conventional spacecraft to perform spatially distributed measurements of the conditions in the ionosphere and exosphere. It is shown that the orbit lifetime can be extended and indeed selected through solar radiation pressure and the end-of-life re-entry of the swarm can be ensured, by exploiting atmospheric drag
Orbit design for future SpaceChip swarm missions
No full textThe effect of solar radiation pressure and atmospheric drag on the orbital dynamics of satellites-on-a-chip (SpaceChips) is exploited to design long-lived orbits about the Earth. The orbit energy gain due to asymmetric solar radiation pressure, considering the Earth shadow, is used to balance the energy loss due to atmospheric drag. Future missions for a swarm of SpaceChips are proposed, where a number of small devices are released from a conventional spacecraft to perform spatially distributed measurements of the conditions in the ionosphere and exosphere. It is shown that the orbit lifetime can be extended and indeed selected through solar radiation pressure and the end-of-life re-entry of the swarm can be ensured, by exploiting atmospheric drag
Space-based geoengineering: challenges and requirements
No full textThe prospect of engineering the Earth's climate (geoengineering) raises a multitude of issues associated with climatology, engineering on macroscopic scales, and indeed the ethics of such ventures. Depending on personal views, such large-scale engineering is either an obvious necessity for the deep future, or yet another example of human conceit. In this article a simple climate model will be used to estimate requirements for engineering the Earth's climate, principally using space-based geoengineering. Active cooling of the climate to mitigate anthropogenic climate change due to a doubling of the carbon dioxide concentration in the Earth's atmosphere is considered. This representative scenario will allow the scale of the engineering challenge to be determined. It will be argued that simple occulting discs at the interior Lagrange point may represent a less complex solution than concepts for highly engineered refracting discs proposed recently. While engineering on macroscopic scales can appear formidable, emerging capabilities may allow such ventures to be seriously considered in the long term. This article is not an exhaustive review of geoengineering, but aims to provide a foretaste of the future opportunities, challenges, and requirements for space-based geoengineering ventures
Electrochromic orbit control for smart-dust devices
No full textRecent advances in MEMS (micro electromechanical systems) technology are leading to spacecraft which are the shape and size of computer chips, so-called SpaceChips, or ‘smart dust devices’. These devices can offer highly distributed sensing when used in future swarm applications. However, they currently lack a feasible strategy for active orbit control. This paper proposes an orbit control methodology for future SpaceChip devices which is based on exploiting the effects of solar radiation pressure using electrochromic coatings. The concept presented makes use of the high area-to-mass ratio of these devices, and consequently the large force exerted upon them by solar radiation pressure, to control their orbit evolution by altering their surface optical properties. The orbital evolution of Space Chips due to solar radiation pressure can be represented by a Hamiltonian system, allowing an analytic development of the control methodology. The motion in the orbital element phase space resembles that of a linear oscillator, which is used to formulate a switching control law. Additional perturbations and the effect of eclipses are accounted for by modifying the linearized equations of the secular change in orbital elements around an equilibrium point in the phase space of the problem. Finally, the effectiveness of the method is demonstrated in a test case scenario
Mars climate engineering using orbiting solar reflectors
No full textThe manned mission is seen as a first step towards a Mars surface exploration base-station and, later, establishing permanent settlement. The location and use of Mars's natural resources is vital to enable cost-effective long-duration human exploration and exploitation missions as well as subsequent human colonization. Planet resources include various crust-lodged materials, a low-pressure natural atmosphere, assorted forms of utilizable energy, lower gravity than Earth's, and ground placement advantages relative to human operability and living standards. Power resources may include using solar and wind energy, importation of nuclear reactors and the harvesting of geothermal potential. In fact, a new branch of human civilization could be established permanently on Mars in the next century. But, meantime, an inventory and proper social assessment of Mars's prospective energy and material resources is required. This book investigates the possibilities and limitations of various systems supplying manned bases on Mars with energy and other vital resources. The book collects together recent proposals and innovative options and solutions. It is a useful source of condensed information for specialists involved in current and impending Mars-related activities and a good starting point for young researchers
Calohypsibius verrucosus subsp. sensu Kaczmarek, Michalczyk & Mcinnes, 2015, sensu
No full text80. Calohypsibius verrucosus (Richters, 1900) sensu lato [T] Calohypsibius verrucosus Richters, 1900 (Jerez & Narváez 2001) H. (C.) verrucosus (Richters, 1900) (du Bois-Reymond Marcus, 1944) Terra typica: Germany (Europe) Brazil: • 22 ° 44 ′S, 45 ° 35 ′W; 1,650 m asl: São Paulo State, Campos do Jordão, mosses or aquatic plants. du Bois-Reymond Marcus (1944) Colombia: • 07°07′N, 73 °02′W; 1,850 m asl: Santander Department, El Diviso Natural Reserve, Cypress forest (Cupresus lusitanica), moss (Cryphaea patens). Jerez & Narváez (2001) Record numbers: Brazil 1, Colombia: 1; total: 2. Remarks: This species has a disjunct distribution, with numerous Europe records and single localities in Asia and South America (McInnes 1994 a). As with C. ornatus (see above), further studies are required to elucidate the taxonomic status of this species and its presence in South America.Published as part of Kaczmarek, Łukasz, Michalczyk, Łukasz & Mcinnes, Sandra J., 2015, Annotated zoogeography of non-marine Tardigrada. Part II: South America, pp. 1-107 in Zootaxa 3923 (1) on page 36, DOI: 10.11646/zootaxa.3923.1.1, http://zenodo.org/record/24193
Orbital dynamics of earth-orbiting 'smart dust' spacecraft under the effects of solar radiation pressure and aerodynamic drag
No full textThis paper investigates how the perturbations due to asymmetric solar radiation pressure, in presence of Earth's shadow, and atmospheric drag can be balanced to obtain long-lived Earth centered orbits for swarms of SpaceChips, without the use of active control. The secular variation of Keplerian elements is expressed analytically through an averaging technique. Families of solutions are then identified where a Sun-synchronous apse-line precession is achieved passively. The long-term evolution is characterized by librational motion, progressively decaying due to the non-conservative effect of atmospheric drag. Therefore, long-lived orbits can be designed through the interaction of energy gain from asymmetric solar radiation pressure and energy dissipation due to drag. In this way, the short life-time of high area-to-mass spacecraft can be greatly extended (and indeed selected). In addition, the effect of atmospheric drag can be exploited to ensure the end-of life decay of SpaceChips, thus preventing long-lived orbit debris
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