scholarly journals Holding Geostationary Satellite at Given Standing Point, Taking into Account Additional Phase Restrictions

Author(s):  
Vladimir Gorbulin ◽  
Evgeniy Kotyashov ◽  
Vladimir Chernyavskiy ◽  
Nikolay Gruzdev

The active lifetime of orbital facilities in the geostationary orbit (GSO), which include stationary artificial earth satellites (SAES) for various purposes, can be more than 15 years. At the same time, in modern conditions of orbital grouping increment, the number of space debris, including those on the GSO, also increases: SAES, which have finished its active lifetime and were not transferred to disposal orbit for some reasons, shards of SAES appeared from collision with meteors or accidents. This leads to the increase of probability of collisions with active SAESs. The listed factors determine the need of considering not only the problem of keeping SAESs in vicinities of position, but also the task of avoiding collisions with space debris objects (SDO), while the costs of the working fluid should not increase. A great attention is being paid to rational power units placing during the projection of new space shuttles, especially those with long useful lifetime. In this article, it is assumed that SESs are equipped with several correction motors, which make it possible to create control accelerations in only several directions, without changing the orientation of the SES itself. In other words, in this task it is assumed that the corrections of the parameters of the AES orbit do not affect the orientation of the SAES itself. This condition is a severe limitation in the synthesis of the SES’s control system. In the considered methodological approach, the costs of the working fluid are set as a functionality from control, which are necessary to perform the next correction, after which the SAES will not have dangerous distances and approaching in projection horizon’s interval. This makes it possible to avoid situations when the decision on control is being made after the SES leaves the vicinity of the station point, and first of all, the approach to the SDO at a distance less than a liminal one. This article provides the results of modeling, which indicate the effectiveness of the proposed solutions. An important advantage compared with the existing methods is the consideration of the movement of the SAES relatively not only to the stationary point, but also to several other objects located in its vicinity, both controlled and uncontrolled. Moreover, there can be any given number of objects.

1991 ◽  
Vol 112 ◽  
pp. 115-125
Author(s):  
Paul D. Maley

Astronomical research continues to use ground-based facilities as a principal means of gathering data. The optical light buckets which are trained each night on celestial sources have historically had to just contend with natural interference. Sunlight, moonlight, clouds, debris created by volcanic eruptions, atmospheric seeing, and aurora are examples of factors which modify the interception and analysis of energy radiated in the optical spectrum and received at the collector end. In the last 5 years the “unnatural” encounters with artificial earth satellites are making themselves more pronounced and have become the subject of this limited study.


Author(s):  
М. В. Братійчук ◽  
А. Г. Кириченко ◽  
В. П. Єпішев

2021 ◽  
Vol 133 (4) ◽  
Author(s):  
K. Sośnica ◽  
G. Bury ◽  
R. Zajdel ◽  
K. Kazmierski ◽  
J. Ventura-Traveset ◽  
...  

AbstractThe first pair of satellites belonging to the European Global Navigation Satellite System (GNSS)—Galileo—has been accidentally launched into highly eccentric, instead of circular, orbits. The final height of these two satellites varies between 17,180 and 26,020 km, making these satellites very suitable for the verification of the effects emerging from general relativity. We employ the post-Newtonian parameterization (PPN) for describing the perturbations acting on Keplerian orbit parameters of artificial Earth satellites caused by the Schwarzschild, Lense–Thirring, and de Sitter general relativity effects. The values emerging from PPN numerical simulations are compared with the approximations based on the Gaussian perturbations for the temporal variations of the Keplerian elements of Galileo satellites in nominal, near-circular orbits, as well as in the highly elliptical orbits. We discuss what kinds of perturbations are detectable using the current accuracy of precise orbit determination of artificial Earth satellites, including the expected secular and periodic variations, as well as the constant offsets of Keplerian parameters. We found that not only secular but also periodic variations of orbit parameters caused by general relativity effects exceed the value of 1 cm within 24 h; thus, they should be fully detectable using the current GNSS precise orbit determination methods. Many of the 1-PPN effects are detectable using the Galileo satellite system, but the Lense–Thirring effect is not.


1994 ◽  
Vol 49 (4) ◽  
pp. 1693-1706 ◽  
Author(s):  
Thibault Damour ◽  
Gilles Esposito-Farèse

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