RU2703696C1 - Autonomous collocation method at near-stationary orbit - Google Patents

Abstract

FIELD: astronautics.

SUBSTANCE: invention relates to control of movement of a group of (two) spacecraft (SC) to keep them in the same narrow (longitude) area in the vicinity of the standing point. One of the spacecraft operates in autonomous (or self-) collocation (SCSC) mode. Working position of SCSC is selected next (in longitude) with working position of adjacent spacecraft. Inclination, eccentricity and av. Greenwich longitude of the SCSC orbit is maintained in the specified ranges, minimizing the discrepancy between the line of nodes and the line of apses during the whole period of active existence of the hull. Evolution of parameters of the orbit of the adjacent spacecraft does not affect the collocation process.

EFFECT: reduction of the width of the field of retention of longitude, as well as creation of favorable conditions (with their possible reflection in international regulations) for longitude collocation of geosynchronous and geostationary spacecraft on near- and geostationary orbits.

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Description

The invention relates to the field of space technology and can be used for collocation (ballistic ensuring guaranteed coexistence in the same area of the near-stationary orbit (CCA) in longitude and latitude relative to the point of standing) of spacecraft (SC).

SCs on the CCA are called geostationary SCs. In the text, spacecraft should be understood as a geostationary spacecraft.

1. The collocation of the spacecraft should be carried out according to agreed schemes known to the enterprise. These analog schemes are reduced to equidistance of the aiming points of the vectors e _n [e _n ; (Ω + ω) _n ] (n = 1,2, ...) and i _n [i _n ; Ω _n ] (n = 1,2, ...) in the corresponding phase planes of the spacecraft and maintaining the ends of the vectors e _n and i _n inside the corresponding regions of the selected radii, the centers of which are the corresponding aiming points. An ideal variant of coordinated collocation for two spacecraft is the separation of longitudes of ascending nodes (Ω _n ) and right ascensions of perigee (Ω + ω) _n aiming points by 180 °, and the arguments of the latitude of the perigee of the spacecraft should be close to zero or 180 °. For three spacecraft, the figure 180 in relation to the aiming points is replaced by 120. However, the seeming simplicity of the schemes hides a complex and costly procedure for managing collocation vectors. Collocation is considered here as a way to control the motion of the centers of mass, guaranteeing against spacecraft collisions. This problem is relevant and satisfactorily solved for two spacecraft (even at zero inclinations) under the conditions:

that is, when the ascending nodes of the orbits are 180 ° apart, for each of the orbits the line of nodes coincides with the apses line, the directions to the ascending node and the perigee of one of the orbits coincide, the other are mutually opposite. The guaranteed minimum inter-satellite distance, with a real eccentricity of the spacecraft orbits of the order of 0.00015, is 12.6 km.

The control centers of all spacecraft located in a single area of latitude and longitude retention follow a unified collocation strategy by exchanging ballistic information.

The consistent collocation method is universal, that is, independent of the type of spacecraft participating in the joint confinement. During the joint operation of the spacecraft, the aiming points, and ideally, the current inclination and eccentricity vectors of the spacecraft’s orbits, should change in phase in a given retention area relative to the working position. Thanks to such a maintenance strategy, the inclination between the orbital planes will be constantly ensured, and the mutual distances between the spacecraft at the lines of intersection of their orbital planes will be no less than the tolerance (10 km).

However, for guaranteed collocation, a permanent process of exchange of ballistic information between spacecraft control centers is required. Such a process may fail, and failures will certainly occur. In addition, the fundamental impossibility of interaction between spacecraft control centers cannot be ruled out. It is easier to be in a state of autonomous collocation (self-collocation): when other spacecraft and their control centers are not involved in the collocation process. When setting such a task, it should be borne in mind that the line of nodes and the line of apses of the orbit of an adjacent spacecraft (SCA) can intersect at an arbitrary angle. Hereinafter, a spacecraft with self-collocation (CASK) means a spacecraft that "took" all responsibility for collocation in a given area of retention in latitude and longitude.

The idea of an autonomous collocation that does not impose any kind of significant obligations on the SKA control center (which means the presence or absence of actions to implement an agreed collocation strategy on the part of such a control center), which allows, by adjusting the inclination and eccentricity vectors, to bypass the rays from all during the day antennas, including global ones, on SKA, without creating thereby shielding effects, it seems relevant and most effective.

2. A known method of autonomous collocation in geostationary orbit (GSO) (RU 2559371 C2). According to this method, which includes translating the inclination and eccentricity vectors onto the boundaries of aiming regions spaced apart from each other (areas of permissible variation of the inclination and eccentricity vectors), measuring the orbit parameters of each spacecraft (SC), determining from them the current values of the orbital parameters of each spacecraft and using small thrust engines to correct the period of revolution, inclination and eccentricity of the orbit, before the spacecraft with self-collocation (CASK) is brought into a given region holding on latitude (inclination) and longitude according to independent trajectory measurements reveals the strategy for controlling the motion of the center of mass of the SKA, in the process of holding clarifies the position of the center of the aiming region on the inclination of the SKA, by making inclination corrections, the inclination vector of the KASK orbit in the phase plane taking into account the season (current direct ascension of the Sun) is set so that the line of nodes of the CASK orbit becomes perpendicular to the line of nodes of the SCA orbit and the center of the aiming region, including the hodograph of the inclination vector of the orbit CASC, perpendicularly displaced from the beginning of the coordinate system [i _x ; i _y ] relative to the line connecting this beginning with the center of the SKA aiming area, by the distance between this center and the beginning of the coordinate system, conduct regular eccentricity corrections to remove the direction of the perigee from the direction to the ascending node of the CASK orbit by the value of the mismatch angle (SD) between the directions to the perigee and the ascending node of the SCA orbit and maintaining this position of the perigee within the specified limits of the aiming region by the eccentric To the Institute, regular KASK orbital inclination corrections are carried out, which, while maintaining a right angle between the lines of the KA orbit nodes, following the end of the inclination vector to its hodograph, the centers of aiming areas are redefined on KASK by the inclination and eccentricity of the KASK orbit when adjusting the strategy for controlling the motion of the center of mass of the SKA and at the increase in the UAS KASK, in cases of a dangerous approach of the KA, the evasion corrections are carried out, which are simultaneous corrections of the longitude and eccentricity of the orbit.

3. A known method of monitoring collocation in geostationary orbit (RU 2558959 C2). According to this method, which includes translating the inclination and eccentricity vectors to the boundaries of aiming regions spaced apart from each other (areas of permissible variation of the inclination and eccentricity vectors), measuring the orbit parameters of each spacecraft (SC), determining from them the current values of the orbital elements of each spacecraft and using small thrust engines to correct the orbital period, inclination and eccentricity of the orbit, to organize collocation autonomous from the SCA before the reduction I monitoring spacecraft (MCA) in a given area of retention in latitude (inclination) and longitude according to independent trajectory measurements reveals the strategy for controlling the motion of the center of mass of the SCA, in the process of holding, specify the position of the center of the aiming area by the inclination of an adjacent SC, by making inclination corrections, the inclination vector of the orbit of the ICA set in the phase plane so that the line of nodes of the orbit of the MCA becomes perpendicular to the line of nodes of the orbit of the adjacent SC and the inclination (i _min ) of the orbit of the MCA relative to the SCA orbit is at least (14 -15) arc.s., carry out the correction of the eccentricity vector:

- so that the sum of the eccentricities of the orbits of the MCA and SKA is about ⁴ порядка10 ^-4 ;

- to remove the direction to the perigee from the direction to the ascending node of the orbit of the ICA by the value of SD SKA;

- to maintain this position of the perigee within the specified limits of the aiming region for eccentricity,

carry out regular complex correction of inclination of the orbit of the ICA:

- to maintain a right angle between the lines of the nodes of the orbits of the spacecraft in the specified limits of the aiming region by inclination;

- to eliminate the age-old component of care for inclination;

- to exceed i _min ,

carry out corrections of longitude (period) so that the origin [ΔL; ΔR - respectively, the deviation along the orbit and the deviation along the radius vector] coincides within the specified limits with the center of the distance ellipse from the SKA, the centers of the aiming areas are redefined on the ICA according to the inclination and eccentricity of the orbit MCA, when adjusting the strategy for controlling the motion of the center of mass of the SKA and with an increase in the SD of the MCA and the SKA, in cases of a dangerous approach of the spacecraft, carry out deviation corrections, which are simultaneous corrections of longitude and eccentricity that orbit.

The basis of analogue 2 and analogue 3 in terms of ballistic support is based on the concept of:

Ballistic information about adjacent spacecraft and the task of separating the inclination and eccentricity vectors in the autonomous collocation mode can be obtained and solved, for example, from the orbital data from the international satellite tracking system, revealing the tactics and strategy of holding the SCA.

The minimum inter-satellite distance under condition (2) is 8 km.

Due to the fact that the moments of passage of the equatorial plane by the devices are ~ 6 hours apart, the spacecraft do not create mutual interference in operation.

Autonomous collocation on the principles of (2) also allows a mismatch according to any of the conditions (2) with respect to the nominal value of 90 ° to 25 °.

Analogue 3 diverges from analogue 2 with ballistic support, which includes the use in the algorithmic representation, in contrast to the hodographs, of the forced evolution of the inclination vector in analogue 2 of the ellipses of distance of the CASA (MCA) from the “alien” spacecraft in the XY plane of the inertial geocentric coordinate system.

And yet, in the above methods of autonomous collocation, adjustment is required for the current parameters of the SKA orbit: SD SKA should be equal to SD KASK.

4. The prior art method of collocation by spacing two SC on the Greenwich longitude, which can be attributed to methods of autonomous collocation. Using thrusters, spacecraft retention corrections are carried out according to Greenwich longitude, eccentricity and latitude (inclination). This method is taken as a prototype. The advantage of the prototype is (if there is a buffer zone of the order of no less than the total error of knowing the current position of both spacecraft in longitude according to the worst case scenario), the spacecraft is almost completely independent of each other. There remains a need to find a “neighbor” (CASK) at the longitude distance from the SKA, as agreed upon by the recommendations of the International Telecommunication Union. The prototype suggests that both spacecraft voluntarily divide among themselves the nominal area of retention in longitude into approximately equal parts. The disadvantages of the prototype are, as a result, the area of longitude retention for each spacecraft is too narrow and, as a result, the increased fuel consumption for the avoidance correction and the increased risks of critical convergence of the vehicles, or the impossibility of guaranteed diversity in longitude. In this area by longitude, there can already be more than one, and not two SKA. The feasibility of the method at the existing population densities of the GSO spacecraft is unlikely. However, if for each of the two spacecraft the retention area in longitude is ± 0.05 °, the functioning of each of them at their working positions will be successful.

For the claimed method of autonomous collocation in a near-stationary orbit, the main common essential features are revealed, such as measurements of the orbit parameters of each spacecraft; determination by them of the current values of the orbital elements of each spacecraft and the use of small thrust engines to correct the period of revolution, inclination and eccentricity of the orbit; for the time before the CASK was brought into the specified retention area in longitude and latitude (inclination) - according to the data of independent trajectory measurements, the identification of the strategy for controlling the motion of the center of mass of the SKA; assignment of a working position (the center of the longitude retention area) of KASK to the SKA longitude retention area.

The technical problem of the invention is the creation of a collocation method completely free of evolution of the orbit parameters of an adjacent spacecraft. The problem posed is solved by the fact that

1. A method of autonomous collocation in a near-stationary orbit, including measuring the orbital parameters of each spacecraft, determining from them the current values of the orbital elements of each spacecraft and performing correction of the orbital period, inclination and eccentricity of the orbit with the help of small thrust engines, before the CASC is brought into the specified holding area in longitude and latitude (inclination) - according to independent trajectory measurements, identifying a strategy for controlling the motion of the center of mass of SKA, assigning a working position (center of the retention area for longitude) KASK for the SKA longitude retention area, characterized in that in the process of bringing to a working position and preparing for the operation of the KASK for the intended purpose, the inclination of the KASK orbit is adjusted to the value i _min calculated by the formula:

where i _min is the minimum permissible inclination of the orbit;

R _GSO - radius of the nominal GSO, 42164 km;

- максимальное наклонение орбиты СКА;

- maximum inclination of the SKA orbit;

e _max - the maximum allowable eccentricity KASK;

D _z - longitude buffer zone between the KASK and SKA retention areas, km;

S _z - nominal exclusion zone, km,

совмещают линию узлов с линией апсид орбиты КАСК, приводят КАСК в находящуюся рядом с областью рабочей позиции СКА область рабочей позиции по долготе с параметрами:while i _{min is} not less than the inclination

combine the line of nodes with the apses line of the KASK orbit, bring the KASK to the area of the working position in longitude located near the area of the SKA working position with the parameters:

- the width of the retention area according to the average Greenwich longitude ± (1-1.5) minutes;

- the gap between the regions in longitude KASK and SKA - D _z / R _GSO ,

the initial target point for the eccentricity vector E ₁ [e _x = 0; e _y = e _max ] is changed to E ₂ [e _x = 0; e _y = -e _max ], with combined orbit corrections, the inclination, the average Greenwich longitude, the eccentricity and the angle of the mismatch of the lines of the nodes and the apse of the KASK orbit during the entire period of active existence at the working position are maintained in the specified ranges, during which time the target points alternate: E ₂ , E ₁ , E ₂ , ....

2. The method of autonomous collocation according to claim 1, characterized in that for e _max > 3e _mouth , where e _mouth is the module of the stable eccentricity vector, in which, by combining the end of its vector with the direction to the Sun, we can obtain the heliosynchronous movement of this vector, correction eccentricity vectors are carried out in order to eliminate only the secular angular drift of the apse line relative to the secular angular drift of the line of KASK orbit nodes.

The average Greenwich longitude is the average of the Greenwich longitudes of perigee and apogee of the KASK orbit.

Probably, at the stage of developing documentation for the spacecraft, the conditions for retaining the CASK in a working position will be known. If not, then the change of retention strategy to GSO can be done at the stage of preparing the spacecraft for regular operation without any damage. Moreover, transferring a geostationary spacecraft to geosynchronous status saves fuel by deducting the inclination corrections required at the stages of bringing geostationary spacecraft to GSO and bringing them to a working position, while reducing the implemented initial inclination to practical zero.

The nominal exclusion zone is the minimum distance between the spacecraft specified by international regulations. Currently, S _z is 10 km.

In FIG. 1 shows a schematic spatial diagram of a collocation, in FIG. Figure 2 shows the daily evolution of CASC in the phase plane [L; ϕ] provided:

The following notation is introduced:

1 - adjacent to the SKA retention area; boundary of the KASK longitude retention area (OAD);

2 - KASK track in the phase plane [L; ϕ] at the boundaries of the EAL;

3 - the boundary of the OAS KASK taking into account the eccentricity of its orbit.

Of course, the actual paths (FIG. 2) differ from that shown in FIG. 1. Longitude due to a change in [argument] of the latitude of the spacecraft (u = ϕ):

varies nonlinearly, but this nonlinearity at latitudes ± 0.1 ° is negligible. In general, it is possible to ignore fluctuations in longitude due to inclination and eccentricity. The latter is possible in view of the fact that the longitude exit from the working area of standing at latitudes exceeding the established norm for geostationary spacecraft should not be considered a violation of international regulation, since at some time in the turn the geosynchronous spacecraft is in an unconfined space of regulations and does not really hinder anyone.

равном 0,1° будем иметь в градусах i_min=3666,67⋅e_max.The minimum buffer zone D _z (Fig. 1) for nominal OUD ± 0.1 ° relative to the working position leaves about 12.3 km (1 minute), the minimum difference (D _z - S _z ) is 2.3 km, and at

equal to 0.1 ° we will have in degrees i _min = 3666.67⋅e _max .

отрицая всякую адаптацию к стратегии удержания СКА, можно заменить на рекомендуемую величину максимального наклонения для геостационарного (но не геосинхронного) КА i_max равную 0,1°. Конечно, если СКА - это геостационарный КА.In FIG. Figure 1 shows the collocation scheme, in the strict sense, of a geosynchronous spacecraft (this is KASK) and a geostationary spacecraft (SKA). Magnitude

Denying any adaptation to the SKA retention strategy, it is possible to replace the recommended maximum inclination for the geostationary (but not geosynchronous) spacecraft i _max equal to 0.1 °. Of course, if the SKA is a geostationary spacecraft.

Minimization of the discrepancy between the line of nodes and the line of apse is mandatory and is the main distinguishing feature of the invention. Without minimizing ω, the spacecraft paths in the phase plane [L; ϕ] will not be as shown in FIG. 2a, they will “walk” across the entire area of retention and regularly enter the SKA area at a daily interval (Fig. 1). The limitation on the value of SD is the same as for the fulfillment of condition (2) in the analogous methods — of the order of ± (25-30) degrees relative to zero. In order for the apse lines and CASK nodes to be in an acceptable coincident position (i.e. (Ω + ω) ≈ Ω), it is necessary to control the CASC latitude argument, since the corrections of the eccentricity vector of the CACS orbit with respect to the change in ω are much more effective than the corrections of the inclination vector with respect to the change in Ω ( because the real eccentricity is much less than the real inclination in radians).

The invention uses two methods for correcting the eccentricity vector.

Method 1. Striving for the selected target point.

выбранной целевой точки, ее меняют на противоположную. Тем самым, значительную часть времени КАСК по средней долготе будет находиться «глубоко» в своей ОУД.In step retaining at selected e _max reached the initial target point [e _x = 0; e _y = e _max ], where e _x = e⋅cos (Ω + ω); e _y = e⋅sin (Ω + ω), change to the opposite point [e _x = 0; e _y = -e _max ]. Next, upon reaching

the selected target point, it is reversed. Thus, a significant part of the average longitude CASK will be “deep” in its OUD.

Used for e _max ≤ 3e _mouth , where e _mouth is the module of the vector of stable eccentricity (Appendix 1).

коррекции проводят со стремлением к целевым точкам (средним позициям). За редким исключением, дополнительных затрат на удержание по средней долготе и эксцентриситету не требуется. В случае неблагоприятного расположения двигателей коррекции, разворот ω на 25° будет иметь статус самостоятельной коррекции вектора эксцентриситета. При е равном (0,0002-0,00065), - наиболее распространенном в области ±(0,05-0,1) градуса, на поворот аргумента широты перигея на 25° потребуется (0,133-0,433) м/с приращения характеристической скорости. Изменение на (25-30) градусов происходит при е равном 0,0002 минимум за 14 суток и за 22 суток в среднем за год. При устранении УР удержание скоро сведется к удержанию ω при е ≈ е_уст, и периодичность коррекций ω увеличится до минимум 30 суток. Это хорошая перспектива, вписывающаяся в строку топливного бюджета по затратам на коррекции удержания по долготе, если говорить о самостоятельной коррекции эксцентриситета. Суточная норма времени работы двигателя малой тяги 8 Гс составляет до 3 ч, что составляет (при массе КАСК порядка 2500 кг) до 0,338 м/с.Этого ресурса работы в суточном цикле из двух коррекций через 12 ч вполне хватит на разворот

даже при модуле эксцентриситета порядка 0,0006: УР может составить 25° за 35 суток минимум и за 55 суток в среднем за год.In method 1, one of the selected thrusters, the layout of which allows regular three-parameter combined correction

corrections are carried out with the desire for target points (middle positions). With rare exceptions, additional retention costs for medium longitude and eccentricity are not required. In the case of an unfavorable arrangement of correction engines, a ω turn of 25 ° will have the status of self-correction of the eccentricity vector. If it is equal to (0.0002-0.00065), the most common in the range of ± (0.05-0.1) degrees, a rotation of the perigee latitude argument by 25 ° will require (0.133-0.433) m / s of the characteristic velocity increment . A change of (25-30) degrees occurs when e is 0.0002 for at least 14 days and for 22 days on average per year. With the elimination of SD, the retention will soon be reduced to the retention of ω at e ≈ e _mouth , and the frequency of corrections ω will increase to a minimum of 30 days. This is a good prospect that fits into the line of the fuel budget for the costs of correcting longitude retention, if we talk about self-correction of eccentricity. The daily operating time of an 8 G small-thrust engine is up to 3 hours, which is (with a KASK weight of about 2500 kg) up to 0.338 m / s. This working resource in the daily cycle of two corrections after 12 hours is quite enough to turn

even with an eccentricity module of the order of 0.0006: SD can be 25 ° in 35 days at least and in 55 days on average per year.

With any eccentricity, the costs of the characteristic velocity for a U-turn of 25 ° will be no more than 2.3 m / s / year.

Method 2. Correction of the secular drift ω with respect to the secular drift Ω.

The noncentrality of the Earth’s gravitational field is the only reason for the secular rotation of the line of nodes (minus 4.9 degrees / year relative to the direction of rotation of the Earth) and the line of apses (plus 9.8 degrees / year). Only one or two SD corrections will be required in two years, and then in the case of an unfavorable location of the correction engines relative to the axes of the coordinate system associated with the spacecraft (SCS).

Use with e _max > 3rd _mouth . The implementation of method 2 eliminates periodic fluctuations of the SD with an amplitude of more than (25-30) degrees.

So, the essence of the invention boils down to the maximum reduction of the EAS due to the exclusion of short- and long-period oscillations from it due to the presence of any eccentricity of the KASK orbit, and the propagation of these oscillations to the region of space where they are not critical.

In terms of tracking the spacecraft at the CCA, imagine that the antenna of the earth station (AP) with the axis of its radiation pattern (NAM) is pointing to the center of the working area of the spacecraft retention. In the case when the spacecraft makes a drift ( _dr ) in latitude within the limits of the beam width ± Θ _dr = ± Δϕ _dr , then for the ZS there is no need to track the spacecraft.

The antenna beam width is usually measured at half power and is Θ _0.5 . Then the absence of the need for tracking the spacecraft meets the condition:

the width of the antenna bottom is expressed in terms of its diameter D and wavelength λ as

In radio lines of command-measuring systems (CIS), frequencies [4-6] GHz are used, which corresponds to λ (0.05-0.075) m, and with a width of Θ _dr equal to 2 °, condition (6), taking into account condition (7), will be satisfied when D is less than or equal to 17.5 λ, that is (0.875-1.300) m. In reality, the antennas of the SIS KIS are significantly larger (equally narrower DNs). Therefore, tracking is necessary at the SIS KIS. On the other hand, onboard the spacecraft, KIS antennas have very wide MDs (at least 70 °), and they are not equipped with automatic guidance devices.

чем это необходимо для выполнения условия (7), то есть система слежения на ЗС связи будет необходима. Бортовые антенны связи устройствами автоматического наведения не оборудуют. С точки зрения реализации радиолиний для обмена связной информацией, опыт разработок КА с дрейфом по широте ±5° и более показывает, что в процессе перемещения КА центральные земные станции не выходят за пределы зоны обслуживания, формируемой бортовой антенной с шириной луча от 2 до 3 градусов, поскольку при движении по широте поддерживается штатная ориентация оси минус X и оси Y ССК, и, из рассмотрения геометрии положения бортового луча связи, следует достаточность отклонения наземной антенны от центра рабочей области в меридианальной плоскости ЗС наземной антенны на угол γ=(ϕ+Δγ), Δγ - линейный доворот угла γ в меридианальной плоскости ЗС, равен 0,178 ϕ: при изменении широты КА на 1 градус Δγ изменится на 10,7 минут. Те же угловые минуты вообще требуются для полного совмещения центра ДН бортовой антенны с центром ДН антенны ЗС. Но при ширине ДН Θ_0,5 бортовой антенны даже в 1° ее доворот на 10,7 минут не требуется.In relation to AP communications. The size of the antennas of such APs will be determined by the energy ratios in the radio line necessary for transmitting information with a given speed and quality. With a high probability, the size of the antennas will be

than it is necessary to fulfill condition (7), that is, a tracking system on the CC of communication will be necessary. Onboard communication antennas are not equipped with automatic guidance devices. From the point of view of implementing radio links for the exchange of connected information, the experience of developing spacecraft with a drift of latitude of ± 5 ° or more shows that in the process of moving the spacecraft, central earth stations do not go beyond the service area formed by an onboard antenna with a beam width of 2 to 3 degrees since the standard orientation of the minus X axis and the SSK axis Y is maintained when moving along the latitude, and, considering the geometry of the position of the onboard communication beam, the sufficiency of the deviation of the ground antenna from the center of the working area in the meridian plane LC terrestrial antenna spine at an angle γ = (φ + Δγ), Δγ - linear dovorot angle γ in the meridian plane of the AP is equal to 0,178 φ: latitude when changing SC 1 degree change Δγ 10.7 minutes. The same angular minutes are generally required for the full alignment of the center of the beam antenna of the onboard antenna with the center of the beam antenna of the AP. But with a beam width Θ _{0.5 of the} on-board antenna, even at 1 °, a 10.7-minute turn-over is not required.

OPU - rotary support device, designed for angular displacement of the direction of maximum radiation (reception) of the AP antenna. OPU ([1] Frolov OP Antennas for earth stations of satellite communications. M., Radio and Communications, 2000, pp. 94-100) should provide, among other things, the implementation of the guidance mode on the spacecraft (if at all specifically, to the spacecraft repeater, author's note.) and its auto tracking. The main parameters of the control system are the limiting values of the angular displacements of the maximum of the beam and the velocity of angular displacements. The control system includes a processor that analyzes the signal level during step-by-step movement of the beam of the antenna antenna, which gives commands for adjusting the evolution of the beam according to the signal level so that each time a stronger signal is received from the SC than that which was received in the previous step.

In [1], p. 95 it says: “After satellite communications finally switched to work with repeaters located on the GSO (we are talking exclusively about geostationary spacecraft, author's note), the electromechanical drive in the form of a screw pusher. This device converts the rotational movement of the electric motor into a linear change in the length of the drive screw. Since the control gear uses small gear ratios of the rotation to translational converter, even when using low-power electric motors, the drive provides the necessary amplifications for moving the mirror, however, at low speeds. ” But high speeds (and these are speeds of the order of (1-2) degrees / s) on GSO and GShO are not necessary.

The description of the control board from [1] is given here to show that the auto-tracking of AP KIS and AP communication antennas is currently a common practice and, therefore, the claimed method of collocation does not require additional serious costs for installing antenna systems with electric drives for precise antenna pointing to the object communication.

The present invention has a limitation: in each of the adjacent areas of longitudes, GSOs cannot be located along a geosynchronous spacecraft.

The proposed method of autonomous collocation at the CCA allows not only 4-5.9 times (from ± 0.1 degrees to ± (0.017-0.025) degrees) to reduce the width of the EAL for the purposes of autonomous (and "friendly", that is, consistent) collocation, but also to review, in view of the overpopulation of the unique GSO, the international regulation (recommendations) on retaining spacecraft at the CCA regarding the possibility of long-term collocation of geosynchronous and practically geostationary spacecraft with geostationary spacecraft already on the CCA.

Hodograph of the eccentricity vector

на эксцентриситет е и аргумент широты перигея ω описывается соотношениями [1], К. Эрике «Космический полет», т. II, часть 1, стр. 388 (см. фиг. 3, цифрами на которой обозначены: 4 - Солнце; 5 - Земля; 6 - КА; 7- орбита КА на текущую эпоху; 8 - перигей орбиты КА; 9 - орбита КА в эпоху, когда центр Земли, перигей и Солнце находятся на одной линии; 10 - радиус большого круга е_уст), учитывающими тангенциальное и нормальное возмущения в плоскости орбиты:The effect of a small speed pulse (speed increments per second)

on eccentricity e and the argument of the latitude of perigee ω is described by the relations [1], K. Erica “Space Flight”, vol. II, part 1, p. 388 (see Fig. 3, the numbers on which indicate: 4 - the Sun; 5 - Earth; 6 - spacecraft; 7 - spacecraft orbit for the current era; 8 - spacecraft orbit perigee; 9 - spacecraft orbit in an era when the center of the Earth, perigee and the Sun are on the same line; 10 - radius of a large circle e _mouth ), taking into account the tangential and normal disturbances in the orbit plane:

where ϑ - the average speed of the spacecraft, 3074 m / s;

η = α-θ is the true anomaly;

θ is the angle between the direction to the Sun and to the perigee of the spacecraft orbit.

Then, substituting the expression η in (3) and using the formulas of the difference of two angles, we obtain:

The first term is at least two orders of magnitude smaller than the rest and is not a constant member, then

When θ = 0

Arguing in a similar way, we will have perigee for the speed of movement (latitude argument):

When θ = 0

Further,

Where

- среднее движение Солнца, с^-1,

- the average movement of the Sun, s ^-1 ,

then

We integrate on a daily basis (on a revolution):

at θ = 0 Δe _day = 0;

at θ = 0

. Световое давление описывается формулойWe give an estimate

. Light pressure is described by the formula

where S is the power of the light wave incident on 1 m ^{2 the} surface of the body, W / m ² ;

A is the reflection coefficient (A = 0 for a completely black body);

s is the speed of light, km / s.

S = 1.4⋅10 ³ W / m ² .

The value of A depends on the reflectivity of the details of the spacecraft construction and in the context of this technical solution should include (conditionally) the gravitational influence of the Sun as "±" relative to the position when the Laplace vector is directed at the Sun. For real spacecraft at the height of the stationary orbit, the values of A are in the range [0.28-0.44]. Based on A = 0.44, we will have P equal to 6.72⋅10 ^-6 n / m ² . Since the light pressure force is F = S'⋅P, where S 'is the mid-sectional area, then

для современных отечественных КА более или менее постоянно и равно порядка (2,3-2,6)⋅10^-2. Тогда, к примеру, при k=0,0259

Attitude

for modern domestic spacecraft, it is more or less constant and equal to the order of (2.3-2.6) ⋅10 ^-2 . Then, for example, with k = 0.0259

в уравнение (13) дает при

значение е=е_уст порядка 0,00045, то есть для того, чтобы скорость движения перигея равнялась скорости движения Солнца, необходимо иметь устойчивый эксцентриситет. Оригинальный вывод формул (11-13) приведен для раскрытия сущности понятия устойчивого эксцентриситета. Энергозатраты на поддержание е_уст практически отсутствуют.As numerical integration shows, the cycle period for eccentricity is slightly more than a year - about 390 days. Substitution

into equation (13) gives for

the value of e = e _{mouth is of the} order of 0.00045, that is, in order for the speed of movement of the perigee to be equal to the speed of movement of the Sun, it is necessary to have a stable eccentricity. The original conclusion of formulas (11-13) is given to reveal the essence of the concept of stable eccentricity. Energy costs for maintaining e _{mouth are} practically absent.

Claims (13)

1. A method of autonomous collocation in a near-stationary orbit, including measuring the parameters of the orbit and determining from them the current values of the orbital elements of each spacecraft (SC), using small-thrust engines to correct the period of revolution, inclination and eccentricity of the orbit, detecting the time before the spacecraft is brought in from self-collocation (CASK) to a given area of confinement by longitude and latitude (inclination) according to independent trajectory measurements of the strategy for controlling the motion of the center of mass of an adjacent SC (SCA), assigned the working position (center of the longitude retention area) of KASK for the SKA longitude retention area, characterized in that in the process of bringing to the working position and preparation for the operation of the KASK for the intended purpose, the inclination of the KASK orbit is adjusted to the value of i _min calculated by the formula:

where i _min is the minimum permissible inclination of the orbit; R _GSO - radius of the nominal GSO equal to 42164 km;

- maximum inclination of the SKA orbit;

- maximum permissible eccentricity of the KASK orbit;

- longitude buffer zone between the KASK and SKA retention areas, km;

- nominal exclusion zone, km, while i _{min is} not less than the inclination

, combine the line of nodes with the apse line of the KASK orbit, bring the KASK to the area of the working position in longitude, located next to the SKA working position area, with the following parameters: - the width of the retention area on average Greenwich longitude: ± (1-1.5) minutes, - longitudinal gap between regions helmets and SKA: D _z / R _GSO eccentricity starting point

change to

the combined orbit corrections support the inclination, the average Greenwich longitude, the eccentricity and the angle of the mismatch between the lines of the nodes and the apse of the KASK orbit during the entire period of active existence at the working position, and during this period the target points alternate regularly: E ₂ , E ₁ , E ₂ , .... 2. The method of autonomous collocation according to claim 1, characterized in that when

Where

- the module of the vector of stable eccentricity, in which, by combining the end of its vector with the direction to the Sun, the heliosynchronous movement of this vector is obtained, the correction of the eccentricity vector is carried out so as to eliminate only the secular angular drift of the apses line relative to the secular angular drift of the line of KASK orbit nodes.

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