共查询到20条相似文献，搜索用时 15 毫秒
1.
Golubev Yu. F. Grushevskii A. V. Koryanov V. V. Lavrenov S. M. Tuchin A. G. Tuchin D. A. 《Solar System Research》2020,54(4):318-328
Solar System Research - We consider space expeditions with a long-term spacecraft stay near the studied celestial body (artificial satellites of small bodies of the Solar System), or expeditions... 相似文献
2.
The problem of optimizing the interplanetary trajectories of a spacecraft (SC) with a solar electric propulsion system (SEPS) is examined. The problem of investigating the permissible power minimum of the solar electric propulsion power plant required for a successful flight is studied. Permissible ranges of thrust and exhaust velocity are analyzed for the given range of flight time and final mass of the spacecraft. The optimization is performed according to Portnyagin’s maximum principle, and the continuation method is used for reducing the boundary problem of maximal principle to the Cauchy problem and to study the solution/ parameters dependence. Such a combination results in the robust algorithm that reduces the problem of trajectory optimization to the numerical integration of differential equations by the continuation method. 相似文献
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V. G. Pol’ 《Solar System Research》2011,45(7):614-621
The paper considers how a spacecraft can be put into orbit around a small asteroid to function as its artificial moon. We
study the general behavior of perturbations that affect the current coordinates of an orbiting spacecraft and estimate the
perturbations caused by the main perturbing factors, i.e., (1) the irregular shape of an asteroid and (2) celestial bodies
of the Solar System. With specific orbital parameters, a long-term targeted operation of a spacecraft can be actualized in
a mission to the asteroid Apophis where the spacecraft will carry a radio beacon transponder. 相似文献
5.
E. N. Slyuta 《Solar System Research》2014,48(3):217-238
The morphometric parameters are examined for the shape of fragments of ordinary chondrites, iron meteorites, S- and C-class stony asteroids, metallic asteroids, and icy small bodies of the Solar System. All small Solar System bodies are shown to have, depending on their composition and, hence, physical and mechanical properties, a specific shape that is unique to a given composition. C-class asteroids, the strength of which is almost three times less than that of S asteroids, differ from the latter in their less elongated shape. No systematic change is observed in the morphometric parameters (increased roundness or sphericity) of small bodies of differing compositions depending on their mass, which suggests that the hypothesis of creep in small Solar System bodies is unlikely to be true. The absence of creep confirms that, regardless of their composition, all small Solar System bodies are solid elastic bodies having an ultimate strength (tensile strength and compressive strength) and a yield strength. 相似文献
6.
New Challenges to Trajectory Design by the Use of Electric Propulsion and Other New Means of Wandering in the Solar System 总被引：1，自引：0，他引：1
Giuseppe D. Racca 《Celestial Mechanics and Dynamical Astronomy》2003,85(1):1-24
The design of spacecraft trajectories is a crucial part of a space mission design. Often the mission goal is tightly related to the spacecraft trajectory. A geostationary orbit is indeed mandatory for a stationary equatorial position. Visiting a solar system planet implies that a proper trajectory is used to bring the spacecraft from Earth to the vicinity of the planet. The first planetary missions were based on conventional trajectories obtained with chemical engine rockets. The manoeuvres could be considered 'impulsive' and clear limitations to the possible missions were set by the energy required to reach certain orbits. The gravity-assist trajectories opened a new way of wandering through the solar system, by exploiting the gravitational field of some planets. The advent of other propulsion techniques, as electric or ion propulsion and solar sail, opened a new dimension to the planetary trajectory, while at the same time posing new challenges. These 'low thrust' propulsion techniques cannot be considered 'impulsive' anymore and require for their study mathematical techniques which are substantially different from before. The optimisation of such trajectories is also a new field of flight dynamics, which involves complex treatments especially in multi-revolution cases as in a lunar transfer trajectory. One advantage of these trajectories is that they allow to explore regions of space where different bodies gravitationally compete with each other. We can exploit therefore these gravitational perturbations to save fuel or reduce time of flight. The SMART-1 spacecraft, first European mission to the Moon, will test for the first time all these techniques. The paper is a summary report on various activities conducted by the project team in these areas. 相似文献
7.
V. I. Shematovich 《Solar System Research》2018,52(5):371-381
There is an astonishing variety of celestial bodies in the outer regions of the Solar System: Europa, with its bizarre surface features, Enceladus, small but geologically active, Titan, the only moon with a significant atmosphere, Pluto, with its nitrogen glaciers, and many others. Over the past 25 years, measurements from spacecraft have shown that many of these celestial bodies are ocean worlds with large volumes of liquid water trapped under icy surfaces. This new group of celestial bodies, ocean worlds, is important for research for several reasons, but the most convincing and at the same time the simplest reason is that they can be potential habitats. Life, as we know it, requires liquid water in addition to energy, nutrients, and a sustainable environment. All these requirements can be met for some of these celestial bodies. The moons of the giant planets on which the presence of the subsurface ocean is established (Europa, Ganymede, Titan, and Enceladus) and their astrobiological potential are discussed. 相似文献
8.
Rosario Brunetto 《Earth, Moon, and Planets》2009,105(2-4):249-255
Micrometeorite bombardment and irradiation by solar wind and cosmic ions cause variations in the optical properties of the small Solar System bodies surface materials. These space weathering processes are reasonably well understood for the Moon and S-type asteroids. The research is based on laboratory experiments performed by several groups on meteorites and minor bodies surface analogues, whose results have been applied to the spectral modeling and interpretation of observations from large surveys and space missions. Recent results from young asteroidal families, and the relation between spectral slopes and dynamical properties, have stressed the role of the solar wind exposure timescale. Space weathering processes remain poorly investigated in the case of other types of asteroids, and they are still unclear in the case of outer Solar System bodies, due to a strong dependence of the weathering process on the original composition. 相似文献
9.
Bruce G. Bills 《Icarus》2005,175(1):233-247
The obliquity, or angular separation between orbit normal and spin pole, is an important parameter for the geodynamics of most Solar System bodies. Tidal dissipation has driven the obliquities of the Galilean satellites of Jupiter to small, but non-zero values. We present estimates of the free and forced obliquities of these satellites using a simple secular variation model for the orbits, and spin pole precession rate estimates based on gravity field parameters derived from Galileo spacecraft encounters. The free obliquity values are not well constrained by observations, but are presumed to be very small. The forced obliquity variations depend only on the orbital variations and the spin pole precession rate parameters, which are quite well known. These variations are large enough to influence spatial and temporal patterns of tidal dissipation and tidal stress. 相似文献
10.
Benefits and features of electric propulsion systems (EPSs) are analyzed in the context of interplanetary travel in the Solar System. A methodological approach to assessing the performance of EPSs is formulated and illustrated by the example of a space mission to Venus. 相似文献
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Solar System Research - In this paper, we summarize the experimental data on the features of the mineral, chemical, and isotopic compositions of minor bodies of the Solar System—asteroids,... 相似文献
13.
SMART-1 is a technology demonstrator for using primary electric propulsion on interplanetary spacecraft. Hence, studying of the interaction of the plasma emitted by the thruster with the environment and the spacecraft is one of the top priorities during the mission. Two experiments (Electronic propulsion diagnostic package and Spacecraft potential, electron and dust experiment) are available to measure the electron densities and temperatures as well as wave electric fields during the operation of the electric propulsion thruster. Additionally, a retarding potential analyser, a quartz microbalance and a solar-cell sample will analyse data from slow charge-exchange ions which are a potential contamination source. ESTEC is developing a 3D particle-in-cell model in order to study the spacecraft/environment interactions on SMART-1 and interpret the measurements. In the present paper, we will review the contamination effects associated with electric propulsion and how the plasma sensors cover them. We further present preliminary results from the numerical simulation and show how the flight data will be used to validate the modelling code. A successful validation of the simulation will support future interplanetary and commercial missions featuring electric propulsion to reduce the risk of contamination and interference with on board instruments. 相似文献
14.
A. V. Devyatkin D. L. Gorshanov V. N. L’vov S. D. Tsekmeister M. S. Chubey 《Kinematics and Physics of Celestial Bodies》2016,32(5):241-244
The use of ground-based and space baseline observations of Solar System bodies is considered. Baseline observations allow one to determine the distance to observed objects and (in some cases) the parameters of their orbital motion. Certain results of baseline observations of near-Earth asteroids and the results of model analysis of spacecraft observations are presented. 相似文献
15.
Finchenko V. S. Ivankov A. A. Golomazov M. M. Shmatov S. I. 《Solar System Research》2020,54(7):595-602
Solar System Research - The article presents aspects of the use of inflatable decelerators in the design of spacecraft (SC) intended for the study of the atmosphere of Venus. The results of the... 相似文献
16.
Andrea Bolle Christian Circi Giuseppe Corrao 《Celestial Mechanics and Dynamical Astronomy》2010,106(2):183-196
Interplanetary transfers represent one of the most interesting themes of astrodynamics, because of its complexity and outcomes
for human exploration of the Solar System. A wide number of works concerning different aspects of the interplanetary mission
have been developed. The examination of these works leads to the conclusion that, by far, there is not a preferential propulsion
system or an optimal trajectory to perform an interplanetary mission, but a precise kind of transfer according to a given
mission profile. Here, minimum time trajectories to Mars for small payload transportation with different electric propulsion
systems have been analyzed; results have been obtained considering the initial impulse given by the Ariane 5 upper stage.
Additionally, an adaptative, multiple shooting optimization algorithm is proposed to solve the problem of optimality in interplanetary
transfers with a low continuous thrust. The algorithm searches for the optimal set of initial Lagrange multipliers solving
the two point problem by adapting the search intervals according to the unsmooth shape of the augmented cost function. 相似文献
17.
There is a growing population of relativistically relevant minor bodies in the Solar System and a growing population of massive
extrasolar planets with orbits very close to the central star where relativistic effects should have some signature. Our purpose
is to review how general relativity affects the orbital dynamics of the planetary systems and to define a suitable relativistic
correction for Solar System orbital studies when only point masses are considered. Using relativistic formulae for the N body
problem suited for a planetary system given in the literature we present a series of numerical orbital integrations designed
to test the relevance of the effects due to the general theory of relativity in the case of our Solar System. Comparison between
different algorithms for accounting for the relativistic corrections are performed. Relativistic effects generated by the
Sun or by the central star are the most relevant ones and produce evident modifications in the secular dynamics of the inner
Solar System. The Kozai mechanism, for example, is modified due to the relativistic effects on the argument of the perihelion.
Relativistic effects generated by planets instead are of very low relevance but detectable in numerical simulations. 相似文献
18.
Solar System Research - This study is devoted to the features of designing the flight trajectories to the Solar System center for two promising Russian spacecraft. The scientific goal of this... 相似文献
19.
Jerry K. Cline 《Celestial Mechanics and Dynamical Astronomy》1979,19(4):405-415
A two body, patched conic analysis is presented for a planetary capture mode in which a gravity assist by an existing natural satellite of the planet aids in the capture. An analytical condition sufficient for capture is developed and applied for the following planet/satellite systems: Earth/Moon, Jupiter/Ganymede, Jupiter/Callisto, Saturn/Titan and Neptune/Triton. Co-planar, circular planetary orbits are assumed. Three sources of bodies to be captured are considered: spacecraft launched from Earth, bodies entering the solar system from interstellar space, and bodies already in orbit around the Sun. Results show that the Neptune/Triton system has the most capability for satellite aided capture of those studied. It can easily capture bodies entering the Solar System from interstellar space. Its ability to capture spacecraft launched from Earth is marginal and can only be decided with better definition of physical properties. None of the other systems can capture bodies from these two sources, but all can capture bodies already in orbit around the Sun under appropriate conditions. 相似文献
20.
Solar System Research - In this paper, we analyze the problems of testing the impact strength of the Exomars-2020 spacecraft on landing. The design features of the landing module of the... 相似文献