共查询到20条相似文献，搜索用时 765 毫秒
1.
Results and analysis are presented for a numerical simulation of solar radiation forces acting on the Spektr-RG spacecraft in operational orbit. The possibility is investigated of compensating the radiation pressure-induced perturbing torque without adding new units and assemblies into the spacecraft configuration. A rationale is given for ways of implementing the compensation techniques that enable 65% compensation of sufficiently large perturbing torques, thus considerably reducing (by 5–6 kg) the propellant consumption in the control system engines and increasing the lifetime of the spacecraft. 相似文献
2.
A. A. Nusinov T. V. Kazachevskaya V. V. Katyushina K. V. Kuimov O. I. Bugaenko V. A. Slemzin N. I. Lebedev 《Solar System Research》2006,40(4):348-353
The CORONAS-F spacecraft crossed the zone of the ring solar eclipse three times on May 31, 2003. A considerable decrease in solar radiation was detected by the spacecraft instruments for these moments. The passages through the eclipse zone were registered by the VUSS instrument, which measured the shortwave solar radiation flux near the hydrogen Lyman alpha line, and by the DIFOS instrument, which was sensitive to infrared, visible, and near-ultraviolet radiation. The eclipse is also clearly seen in solar images obtained by the X-ray SPIRIT telescope. Some details of measurement results are discussed. 相似文献
3.
Dyfrig Jones 《Planetary and Space Science》1982,30(4):399-410
Terrestrial myriametric radiation (non-thermal continuum) observed by the GEOS 1 spacecraft is used to determine the radial profile of plasma density at the equatorial plasmapause. The method utilises the properties of a radio window through which the radiation propagates. The radial density profile obtained by remote sensing is compared with that implied from natural electrostatic emissions as the spacecraft approaches the equatorial source region. The TMR profile appears to be that of the cold plasma whereas the frequencies of the intense non-equatorial emissions beyond the plasmapause are governed by the hot and cold components. Ray-tracing and polarisation computations indicate that a simplistic interpretation of direction-finding measurements using the spinning dipole technique could lead to erroneous source directions under certain circumstances. In such cases if the spacecraft orientation is known corrections can be applied to yield the true direction. 相似文献
4.
S. I. Shmatov 《Solar System Research》2018,52(7):644-648
The effect of solar radiation on two typical external surfaces of a spacecraft is studied using numerical simulation by considering real geometry (geometry deviation from the nominal shape). The results of simulation are presented in this paper. Geometry deviations are simulated by two types of regular external heterogeneities. We compare the force and torque characteristics of solar radiation on nonuniform surfaces with similar characteristics for nominal surfaces and we find that the disagreement between them can reach 90% both in absolute value and sign. This means that it is necessary to consider the deviations in geometry from nominal for proper design and operation of spacecraft. 相似文献
5.
Nicole Borderies Pierre-yves Longaretti 《Celestial Mechanics and Dynamical Astronomy》1990,49(1):69-98
The purpose of this paper is to present a model for the radiation pressure acceleration of a spherical satellite, due to the radiation reflected by a planet with a uniform albedo. A particular choice of variables allows one to reduce the surface integrals over the lit portion of the planet visible to the satellite to one-dimensional integrals. Exact analytical expressions are found for the integrals corresponding to the case where the spacecraft does not "see" the terminator. The other integrals can be computed either numerically, or analytically in an approximate form. The results are compared with those of Lochry (1966). The model is applied to Magellan, a spacecraft orbiting Venus. 相似文献
6.
A methodology is presented for the joint computation of aerodynamic and radiation forces acting on orbital spacecraft. Special attention is given to the computation of the radiation component. The reliability of the results is confirmed by comparing them with those obtained by other methods and flight measurements. Results are presented of a study of the combined impact induced by solar radiation and the upper atmosphere on the small spacecraft MKAFKI (Zond-PP). 相似文献
7.
The resonance terms produced by the effect of direct solar radiation pressure on the motion of a spacecraft in the oblate
field of the earth are analyzed. The spacecraft was assumed axially symmetric with a despun antenna and solar panels. A canonical
transformation technique is developed, based on the Bohlin technique of expansion in fractional powers, using Lie series and
transformation as well as the concept of the Delaunay anomaly. The developed technique, applied to the problem averaged over
the mean anomaly, is suitable in the presence of more than one resonant vector. 相似文献
8.
利用脉冲星钟模型能高精度地预报脉冲星脉冲到达太阳系质心的时间。基于脉冲星时、空参考架可实现各类空间飞行器的自主导航。讨论了脉冲星钟的模型和脉冲星导航系统的框架结构,描述了脉冲星导航的基本原理和算法。指出脉冲星导航系统对脉冲星脉冲到达探测器时刻的测量精度,是决定空间飞行器位置解算精度的关键因素。脉冲星导航观测采用的原子钟如果足够稳定,则空间飞行器位置的解算方法可以简化。在脉冲星导航系统计时观测精度达到或优于几十微秒量级时,脉冲星视差、相对论效应的影响是不可忽略的。对脉冲星导航系统开发设计中的关键技术和进一步研究的主要问题进行了初步分析和讨论。 相似文献
9.
A. L. Poroshina 《Astronomy Letters》2013,39(12):876-881
The ephemerides of satellites of major planets are needed in planning spacecraft missions both for studying the satellites themselves and for navigational support during the flights of spacecraft in the vicinity of planets. In addition, accurate numerical theories of motion of the natural satellites of major planets make it possible to increase the accuracy of the ephemerides of their central planets based on positional (photographic and CCD) observations of the satellites. Numerical theories of Neptune’s satellites, Triton and Nereid, constructed within the framework of the ERA software package developed at the Institute of Applied Astronomy of the Russian Academy of Sciences are presented. 相似文献
10.
The results of measuring UV radiation onboard the CORONAS-F spacecraft during solar flares in 2001–2003 are considered. Some conclusions from the analysis of variations of solar-flare emission in several spectral intervals, namely, in soft X-rays, in the 10-to 130-nm range, and in the band near 120 nm, are discussed. The data were obtained by the VUSS-L and SUFR instruments. Time and energy characteristics of flares recorded onboard the CORONAS-F spacecraft are compared to the GOES measurements in the interval 0.1–0.8 nm and to the SOHO measurements of UV radiation in the 26-to 34-nm band. In particular, it is demonstrated that UV radiation is generated several (1–10) minutes before X-ray emission for most flares considered in the study. It is shown that the energy of flare emission in the extreme ultraviolet is usually not greater than ～10% of its preflare level and that energy fluxes in different wavelength ranges are related by a power law. Such an analysis makes it possible to better understand the mechanism of flare development. 相似文献
11.
The intensity ratio of the components of the MgXII doublet was measured during a solar flare using one of the instruments on the Solar Maximum Mission spacecraft. The results are in good agreement with those reported previously and explained in terms of the effect of the trapping of resonance radiation. 相似文献
12.
《New Astronomy》2020
The purpose of this paper is to make a numerical search for natural orbits that can be used for a spacecraft to study a possible small moon of Pallas. There are many speculations about the existence of a small companion around this large asteroid, so finding and classifying orbits around this possible celestial body is an interesting problem in astrodynamics and that can be used for a spacecraft to observe this body. It is assumed that this moon has a radius that can vary from 0.125 to 1 km and that is located 750 or 500 km away from the center of Pallas. The idea is to show the effects of this parameter in the orbits around this moon. It means that the moon is much smaller than Pallas, so Keplerian orbits are not possible around it. To solve this problem, it is possible to find some special orbits that are called "Quasi Satellite Orbits" (QSO). They are orbits dominated by the gravity of Pallas, but that use the smaller perturbation from the moon to keep the spacecraft close to it. The present work searches for orbits that make the spacecraft to remain at given limits in its distance from the moon, like in the range from 3 to 50 km, the values used as an example in the present paper. This value is used because it is a good range to observe the body without getting to close to it, so reducing the risks of collisions. Each trajectory can be identified by the initial conditions of the spacecraft with respect to the moon, which means its initial position and velocity. The dynamics considers the restricted three-body problem and the influence of the solar radiation pressure, because some spacecraft may have higher values for the area-to-mass ratio, which gives a non-negligible effect in the trajectory of the spacecraft. 相似文献
13.
A. A. Lyubomudrov 《Solar System Research》2013,47(7):561-563
The mechanism for generating electric potentials and currents in conductors of electronic equipment on board spacecraft subjected to space radiation is examined. Radiation potentials and currents are calculated for a system that consists of two insulated conductors. Using the simplest model we obtain results which can be expanded to a more complex geometry of conductors. 相似文献
14.
Golubev Yu. F. Tuchin A. G. Grushevskii A. V. Koryanov V. V. Tuchin D. A. Morskoy I. M. Simonov A. V. Dobrovolskii V. S. 《Solar System Research》2016,50(7):597-603
The development of a methodology for designing trajectories of spacecraft intended for the contact and remote studies of Jupiter and its natural satellites is considered. This methodology should take into account a number of specific features. Firstly, in order to maintain the propellant consumption at an acceptable level, the flight profile, ensuring the injection of the spacecraft into orbit around the Jovian moon, should include a large number of gravity assist maneuvers both in the interplanetary phase of the Earth-to-Jupiter flight and during the flight in the system of the giant planet. Secondly, the presence of Jupiter’s powerful radiation belts also imposes fairly strict limitations on the trajectory parameters.
相似文献15.
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
16.
Kenneth R. Lang 《Earth, Moon, and Planets》1995,70(1-3):1-20
The Sun is enveloped by a hot, tenuous million-degree corona that expands to create a continuous solar wind that sweeps past all the planets and fills the heliosphere. The solar wind is modulated by strong gusts that are initiated by powerful explosions on the Sun, including solar flares and coronal mass ejections. This dynamic, invisible outer atmosphere of the Sun is currently under observation with the soft X-ray telescope aboard the Yohkoh spacecraft, whose results are presented. We also show observations from the Ulysses spacecraft that is now passing over the solar pole, sampling the solar wind in this region for the first time. Two other spacecraft, Voyager 1 and 2, have recently detected the outer edge of the invisible heliosphere, roughly halfway to the nearest star. Magnetic solar activity, the total radiative output from the Sun, and the Earth's mean global surface temperature all vary with the 11-year sunspot cycle in which the total number of sunspots varies from a maximum to a minimum and back to a maximum again in about 11 years. The terrestrial magnetic field hollows out a protective magnetic cavity, called the magnetosphere, within the solar wind. This protection is incomplete, however, so the Sun feeds an unseen world of high-speed particles and magnetic fields that encircle the Earth in space. These particles endanger spacecraft and astronauts, and also produce terrestrial aurorae. An international flotilla of spacecraft is now sampling the weak points in this magnetic defense. Similar spacecraft have also discovered a new radiation belt, in addition to the familiar Van Allen belts, except fed by interstellar ions instead of electrons and protons from the Sun. 相似文献
17.
M. P. Sinitsyn 《Earth, Moon, and Planets》2013,110(1-2):29-39
This article provides some astronomical background for a systematic study of the lunar regolith. The Moon, like other atmosphere-less bodies, is the subject to all kinds of cosmic radiation, which are imprinted in the lunar surface. Therefore, the study of the lunar regolith for signs of cosmic radiation can assist to trace the history of changes in these emissions over time. Mostly changes in the solar wind and galactic cosmic rays are very interesting at time intervals from a few tens of millions of years to several billion years. The paper develops the idea of paleoregolith, the possible location of which can be seen on the slopes of some craters (Euler, Bessel) in images obtained by camera of LRO spacecraft (LROC). Because of the complexities of placing a spacecraft on the slopes of craters, some other possible locations of paleoregolith are offered to consideration. To study the recent history of the evolution of the Moon and the inner planets (up to 200 million years) the stored information in impact and volcanic melts, which are widely represented in the LROC images, should be considered. 相似文献
18.
The thermophysics of asteroids has become an important frontier for the research of asteroids in recent years. In this paper, we have introduced the thermophysical models commonly used in this field, by using these thermophysical models and combining with the data observed by the space or ground-based IR telescopes, some thermophysical parameters of asteroids, such as the thermal inertia, geometric albedo, effective diameter, surface roughness, and surface temperature, etc., can be derived. We have mentioned also the shape model and IR observation of asteroids, as well as the obtained thermophysical parameters for a part of asteroids. These thermophysical parameters can be further applied to studying the asteroids’ Yarkovsky effect, YORP effect, and so on, even can provide the relevant information for the spacecraft landing on the asteroid surface and the return mission of a spacecraft after the asteroid sampling. 相似文献
19.
The strongly perturbed dynamical environment near asteroids has been a great challenge for the mission design. Besides the non-spherical gravity, solar radiation pressure, and solar tide, the orbital motion actually suffers from another perturbation caused by the gravitational orbit–attitude coupling of the spacecraft. This gravitational orbit–attitude coupling perturbation (GOACP) has its origin in the fact that the gravity acting on a non-spherical extended body, the real case of the spacecraft, is actually different from that acting on a point mass, the approximation of the spacecraft in the orbital dynamics. We intend to take into account GOACP besides the non-spherical gravity to improve the previous close-proximity orbital dynamics. GOACP depends on the spacecraft attitude, which is assumed to be controlled ideally with respect to the asteroid in this study. Then, we focus on the orbital motion perturbed by the non-spherical gravity and GOACP with the given attitude. This new orbital model can be called the attitude-restricted orbital dynamics, where restricted means that the orbital motion is studied as a restricted problem at a given attitude. In the present paper, equilibrium points of the attitude-restricted orbital dynamics in the second degree and order gravity field of a uniformly rotating asteroid are investigated. Two kinds of equilibria are obtained: on and off the asteroid equatorial principal axis. These equilibria are different from and more diverse than those in the classical orbital dynamics without GOACP. In the case of a large spacecraft, the off-axis equilibrium points can exist at an arbitrary longitude in the equatorial plane. These results are useful for close-proximity operations, such as the asteroid body-fixed hovering. 相似文献
20.
Nonsteady interaction of plasma with bodies moving in space 总被引：2，自引：0，他引：2
Xiao-Qing Li 《Astrophysics and Space Science》1989,153(2):311-326
Nonsteady interactions between spacecraft and plasma are investigated in detail. The system of equations describing these interactions is obtained. It is shown that an electromagnetic soliton is excited via the modulational instabilities, which result from the radiation of antenna systems on the body which are the source of waves. In the meantime the density in far wake diminishes, and its disturbance becomes also a soliton if the pump wave is sufficiently intense. 相似文献