35,223 research outputs found
Navigating to the Moon along low-energy transfers
No full textThis paper presents a navigation strategy to fly to the Moon along a Weak Stability Boundary transfer trajectory. A particular strategy is devised to ensure capture into an uncontrolled relatively stable orbit at the Moon. Both uncertainty in the orbit determination process and in the control of the thrust vector are included in the navigation analysis. The orbit determination process is based on the definition of an optimal filtering technique that is able to meet accuracy requirements at an acceptable computational cost. Three sequential filtering techniques are analysed: an extended Kalman filter, an unscented Kalman filter and a Kalman filter based on high order expansions. The analysis shows that only the unscented Kalman filter meets the accuracy requirements at an acceptable computational cost. This paper demonstrates lunar weak capture for all trajectories within a capture corridor defined by all the trajectories in the neighbourhood of the nominal one, in state space. A minimum Delta v strategy is presented to extend the lifetime of the spacecraft around the Moon. The orbit determination and navigation strategies are applied to the case of the European Student Moon Orbiter
Orbit determination and control for the European Student Moon Orbiter
No full textThis paper presents the preliminary navigation and orbit determination analyses for the European Student Moon Orbiter. The severe constraint on the total mission Delta nu and the all-day piggy-back launch requirement imposed by the limited available budget, led to the choice of using a low-energy transfer, more specifically a Weak Stability Boundary one, with a capture into an elliptic orbit around the Moon. A particular navigation strategy was devised to ensure capture and fulfil the requirement for the uncontrolled orbit stability at the Moon. This paper presents a simulation of the orbit determination process, based on an extended Kalman filter, and the navigation strategy applied to the baseline transfer of the 2011-2012 window. The navigation strategy optimally allocates multiple Trajectory Correction Manoeuvres to target a so-called capture corridor. The capture corridor is defined, at each point along the transfer, by back-propagating the set of perturbed states at the Moon that provides an acceptable lifetime of the lunar orbit. (C) 2012 Elsevier Ltd. All rights reserved
Moon, J J, 410908
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/405784Surname: MOON. Given Name(s) or Initials: J J. Military Service Number or Last Known Location: 410908. Missing, Wounded and Prisoner of War Enquiry Card Index Number: 52215.246515
Item: [2016.0049.38061] "Moon, J J, 410908
The scientific case for renewed human activities on the Moon
No full textIt is over 30 years since the last human being stood on the lunar surface and this long hiatus in human exploration has been to the detriment of lunar and planetary science. The primary scientific importance of the Moon lies in the record it preserves of the early evolution of a terrestrial planet, and of the near-Earth cosmic environment in the first billion years or so of Solar System history. This record may not be preserved anywhere else; gaining proper access to it will require a human presence. Moreover, while this will primarily be a task for the geosciences, the astronomical and biological sciences would also benefit from a renewed human presence on the Moon, and especially from the establishment of a permanently occupied scientific outpost
Larry J. Moon
No full textLarry J. Moon is pictured his school year at Naples Elementary. He is the son of Mariona Lyman and Jeannie Simper Moon. He married Ann Trainor. He was a cowboy and rancher and was tragically killed in a tractor accident on January 25, 1975
Letter to F.D. Moon from J. Woods regarding thanking Moon for a good experience working at Douglass High School
No full textLetter to F.D. Moon expressing thanks for a good experience working at Douglass High School
John Wallace and Ella C. Moon Family
No full textJohn Wallace and Ella C Moon with their children Mary Joan, David, Deana, and Mike Moon. Photo can be located on page 322 of the Jensen Utah Book
Children of Henry Moroni Moon
No full textWallace, Vera, Edith, Velma, and Ferron Moon are children of Maggie Bell and Henry Moroni Moon. Photo can be located on page 320 of the Jensen Utah Book
Moon Phases, Mood and Stock Market Returns: International Evidence
No full textWe employ recent data from 59 international emerging and mature stock markets to provide new evidence of a lunar cycle (full and new moon) effect on their stock market returns. Using a TGARCH model, we further examine the linkages between efficient-market theory, calendar-related effects and investors' mood resulted from moon phases. The empirical results show significant full moon effects in 6 markets, and significant new moon effects in 8 markets. In line with the theory, we report significant positive effect of new moon on stock market returns in 5 cases (UK, Switzerland, Bangladesh, Chile and Cyprus), while a negative effect of full moon is reported for the case of Jordan only. In addition, we find that lunar effects are strongly influenced by the calendar anomalies (Monday effect and January effect); several markets -mostly emerging markets- show evidence of full/new moon effects as well as Monday/January effects (Bangladesh, Brazil, Chile, Tunisia, Belgium, Cyprus). Further, we prove that the lunar phases are stronger outside America. These findings are recommended to investors, financial managers and analysts dealing with international stock indices
- …
