Optimization of satellite constellations in the moon

Nowadays, we return to live a period of lunar exploration. China, Japan and India heavily invest in missions to the moon, and then try to implement manned bases on this satellite. These bases must be installed in polar regions due to the apparent existence of water. Therefore, the study of the feasibility of satellite constellations for navigation, control and communication recovers importance. The Moon's gravitational potential and resonant movements due to the proximity to Earth as the Kozai-Lidov resonance, must be considered in addition to other perturbations of lesser magnitude. The usual satellite constellations provide, as a basic feature, continuous and global coverage of the Earth. With this goal, they are designed for the smallest number of objects possible to perform a specific task and this amount is directly related to the altitude of the orbits and visual abilities of the members of the constellation. However the problem is different when the area to be covered is reduced to a given zone. The required number of space objects can be reduced. Furthermore, depending on the mission requirements it may be not necessary to provide continuous coverage. Taking into account the possibility of setting up a constellation that covers a specific region of the Moon on a non-continuous base, in this study we seek a criterion of optimization related to the time between visits. The propagation of the orbits of objects in the constellation in conjunction with the coverage constraints, provide information on the periods of time in which points of the surface are covered by a satellite, and time intervals in which they are not. So we minimize the time between visits considering several sets of possible constellations and using genetic algorithms.

Influence of nonsphericity of planetary satellites and perturbation of the third-body on the artificial satellites motion

Some orbital characteristics of lunar artificial satellites is presented taking into account the perturbation of the third-body in elliptical orbit and the non-uniform distribution of mass of the Moon. We consider the development of the non-sphericity of the Moon in zonal spherical harmonics up to the ninth order and sectorial harmonic C 22 due to the lunar equatorial ellipticity. The motion of the artificial satellite is studied under the single-averaged analytical model. The average is applied to the mean anomaly of the satellite to analyze low-altitude orbits which are of highest importance for future lunar missions. We found families of frozen orbits with long lifetimes for the problem of an orbiter travelling around the Moon.

Where no man has gone before [microform] : a history of Apollo lunar exploration missions /

Mode of access: Internet.

Deep and near space tracking stations in support of lunar and planetary exploration missions

The aim of this dissertation is to describe the methodologies required to design, operate, and validate the performance of ground stations dedicated to near and deep space tracking, as well as the models developed to process the signals acquired, from raw data to the output parameters of the orbit determination of spacecraft. This work is framed in the context of lunar and planetary exploration missions by addressing the challenges in receiving and processing radiometric data for radio science investigations and navigation purposes. These challenges include the designing of an appropriate back-end to read, convert and store the antenna voltages, the definition of appropriate methodologies for pre-processing, calibration, and estimation of radiometric data for the extraction of information on the spacecraft state, and the definition and integration of accurate models of the spacecraft dynamics to evaluate the goodness of the recorded signals. Additionally, the experimental design of acquisition strategies to perform direct comparison between ground stations is described and discussed. In particular, the evaluation of the differential performance between stations requires the designing of a dedicated tracking campaign to maximize the overlap of the recorded datasets at the receivers, making it possible to correlate the received signals and isolate the contribution of the ground segment to the noise in the single link. Finally, in support of the methodologies and models presented, results from the validation and design work performed on the Deep Space Network (DSN) affiliated nodes DSS-69 and DSS-17 will also be reported.

Planning, operations and data handling of planetary science missions

Dissertação para obtenção do Grau de Mestre em Engenharia Física

Development of the gas chromatograph – mass spectrometer to investigate volatile species in the lunar soil for the Luna-Resurs mission

Since the analysis of the lunar rocks and soil samples, brought to Earth by the Apollo missions, it is believed that the Moon has a waterless nature and also other volatile species are strongly depleted. Advancement in analysis techniques helped to identify water and other volatile species in lunar volcanic glasses. Additionally, recent lunar space missions detected water and volatile organic compounds in the region of the lunar poles where permanently shadowed craters are existing. All known lunar soil samples available on Earth come from the lunar near side, close to the equator. To verify the most recent measurement results and to enhance the knowledge of the geological history of the Moon it is of high interest to perform in situ measurements on the lunar poles. For this reason the Russian space agency, Roskosmos, developed aprogram for the scientific exploration of the lunar poles. The Gas Analysis Package (GAP) is part of the selected scientific payload aboard the Luna-Resurs Lander. This instrument uses pyrolytic cells and will apply laser spectroscopy, gas chromatography and mass spectrometry to detect and analyze volatile components trapped in the lunar soil. An existing ion optical design of a compact reflectron type time-of-flight mass spectrometer, originally built for the MEAP/P-BACE balloon mission, was chosen as a part of the GAP instrument. The scope of this thesis is the development of the interface between gas chromatography (GC) and this Neutral Gas Mass Spectrometer (NGMS) to perform coupled GC-MS measurements. In the first part of this thesis the interfacing concept was developed and verified by coupling the NGMS prototype to gas chromatography. The second part of this thesis is devoted to the development of the NGMS flight version.

Navigation design and flight dynamics operations of the ArgoMoon cis-lunar CubeSat.

On November 16, 2022, the NASA’s Space Launch System (SLS) has been launched for the first time in the context of Artemis-1 mission where, together with the Orion Multi-Purpose Crew Vehicle, a set of 10 CubeSats have been delivered into a translunar trajectory. Among the small satellites deployed during Artemis-1 there is ArgoMoon, a 6U CubeSat built by the Italian company Argotec and coordinated by Italian Space Agency (ASI). The primary goal of ArgoMoon is to capture images of the Interim Cryogenic Propulsion Stage. The ArgoMoon trajectory has been designed as a highly elliptical geocentric orbit, with several encounters with the Moon. In order to successfully fly ArgoMoon along the designed cis-lunar trajectory, a ground-based navigation system has been developed exploiting the guidance techniques also used for regular deep space missions. The navigation process is subdivided into Orbit Determi- nation (OD) and a Flight Path Control (FPC), and it is designed to follow the reference trajectory, prevent impacts with the Earth and the Moon, intensively test the navigation techniques, and guarantee the spacecraft disposal at the end of the mission. The work done in this thesis has accomplished the navigation of ArgoMoon, covering all aspects of the project life, from pre-launch design and analysis to actual operations. Firstly, the designed navigation process and the pre-mission assessment of its performance will be presented. Then, the results of the ArgoMoon navigation operations performed after the launch in November 2022 will be described in detail by discussing the main encountered challenges and the adopted solutions. The results of the operations confirmed the robustness of the designed navigation which allowed to accurately estimate the trajectory of ArgoMoon despite a series of complex events.

Does the lunar phase have an effect on sudden unexpected death in epilepsy?

The incidence of sudden unexpected death in epilepsy (SUDEP) in Our epilepsy unit over an 8-year period was analyzed to determine a possible association between phase of the moon and SUDEP. Analysis revealed that the number of SUDEPs was highest in full moon (70%), followed by waxing moon (20%) and new moon (10%). No SUDEPs Occurred during the waning cycle. These preliminary findings suggest that the full moon appears to correlate with SUDEP. (C) 2008 Elsevier Inc. All rights reserved.

Calibration, selection and mosaicing of SMART-1 AMIE images

Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores

Public perspective towards social impact of chang e lunar probe program

The present article is based on the MA thesis of Hou Bowen (Ph.D candidate) and on the presentation made at the ISA World Congress of Sociology held in Yokohama (Japan) on July 2014 at the Session on “Assessing Technologies: Global Patterns of Trust and Distrust” of RC23-Sociology of Science and Technology.

Influência lunar sobre plantas hortícolas

The aim of this paper is the study of moon effects on ten different crops divided in four groups: 1) salad and cole crops (lettuce, endive, cabbage, cauliflower); 2) root crops (beet, carrot, radish, turnip); 3) bulb crops (onion); 4) solanaceous fruits (eggplant). The design of the experiment was randomized blocks, with four replications, the different treatments being the four phases of the moon. The analyses of variance are given in the work of Simão (1953) and the analises of the mean in tables 1 to 2. The main conclusions are: 1) No difference in production were found related to different moon phases, even it the crops supposed to be sensible to moon effects. 2) In a few cases, where some increase in production was observed, such increase could be atributed by other apents 3) The agents supposed to interfere with increase in production were temperature and photoperiodism, rather than moon phases. 4) The most sensible crops to low temperature, during the night, were: lettuce, endive, cauliflower, cabbage, carrots, turnips and radish. 5) The most sensible crops to both low temperature and photoperiodism were: onion and beet. 6) The moon phases supposed to have opposed effects, namely full-moon and half-moon, gave mixed results sometimes both giving the best yield simultaneously and sometimes giving the poorest crops. 7) As a final conclusion, no moon effects could be detectable in the present experiment.

Influência do ciclo lunar na captura de Aedes scapularis (Diptera, Culicidae) na Mata Atlântica do Paraná

From October 1995 to January 1996 Aedes (Ochlerotatus) scapularis (Rondani, 1948) was studied in a small area of the Atlantic Forest, Serra do Marumbi, Morretes, Paraná, Brazil. Adults were captured with Shannon light traps for 48 nights, representing 12 nights for seven time intervals. Traps were operated from dusk to dawn. The influences on flight activity of the lunar phase, ambient temperature, relative humidity, and rainfall were analyzed. Ae. scapularis had a flight behaviour different in each of the four lunar phases. In relation to flight period, the species showed higher activity during the first three lunar intervals. Among the climatic variables, temperature and relative humidity positively influenced flight activity during the night.

Influência do ciclo lunar na captura de morcegos Phyllostomidae

A influência da luz da lua no padrão de atividade de morcegos já foi documentada em algumas espécies. Geralmente os morcegos reagem ao aumento da iluminação reduzindo o uso de espaços abertos e restringindo a atividade de forrageio ou a duração do período de atividade. Para estabelecer a influência do ciclo lunar na eficiência de captura de morcegos, foi realizada uma análise com 28 noites de capturas no sudeste do Brasil. A taxa de captura e a riqueza de espécies apresentaram relação linear inversa com a porção iluminada pela lua. Das espécies mais freqüentemente capturadas, apenas duas apresentaram relação significativa e negativa com o aumento da iluminação pela lua. Maiores variações na riqueza de espécies foram observadas em morcegos catadores e nectarívoros. Os dias após a lua nova são os mais produtivos em relação a capturas e riqueza. A riqueza local não pode ser totalmente amostrada se a amostragem for restrita a qualquer período do ciclo lunar. Para estudar a comunidade de morcegos é mais apropriado realizar amostragem durante todo o ciclo lunar.