RU2771191C1 - Space service system and its functioning method - Google Patents

Abstract

FIELD: space technology.

SUBSTANCE: group of inventions relates to the maintenance of artificial satellite systems for various purposes, including groups of orbits with equal or close inclination (i), distributed in the equatorial plane along the longitude of the ascending node (Ω). A space service system (hereinafter – SS) contains means of servicing (hereinafter – SM) satellites, base spacecraft (hereinafter – BSC) in home orbits, means of receiving and processing data on the state and functioning (hereinafter – DSF) of SS and transferring the results of DSF processing to BSC. Moreover, home orbits are selected with a focal parameter (p') as small as possible of the characteristic focal parameter (p) of orbits of satellites from corresponding service areas, and with an inclination (i') close to characteristic inclination (i) of orbits of satellites from the same service areas. BSC contain payload modules (PL) and modular interorbital transport vehicles (hereinafter – ITV) for moving SM between BSC and SS. The motion control of ITV is based on predictions of failure times of SS and includes the adjustment of the precession velocity (Ω') of a plane of an osculating orbit of ITV by a certain change in the focal parameter of the specified orbit.

EFFECT: efficiency of SS maintenance is increased.

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Description

Technical field

The inventions relate to the maintenance of systems of artificial satellites for various purposes (monitoring, navigation, communications, etc.) located in orbits that can be grouped according to the proximity (or equality) of their inclinations (i) and heights (focal parameters p) and distributed in the equatorial plane in the longitude of the ascending node (Ω).

Examples of such satellite systems are GLONASS or GPS systems (see [1] GPS vs GLONASS: which system is better. 12/16/2016: https://gpsmarker.ru/info/blog/gps-vs-glonass-kakaya-sistema- luchshe.html), which uses the same type of orbits of approximately the same inclination (63.6° and 64.3°), evenly spaced in the parameter Ω. On each of the orbits (number 3 or 6) there are several ICs evenly spaced along the orbit (working number 8 or 4).

Such a construction of satellite systems is convenient both from the point of view of their intended purpose and maintenance (the latter requires a smaller number of service spacecraft (SC) and less energy for flights to different serviced satellites (OS). By "maintenance" we mean operations such as refueling , repair, inspection, withdrawal (replacement), etc.

Service facilities (SOs), in particular, service spacecrafts, can be delivered to serviced ISs using interorbital transport vehicles (ITVs) with jet engines (LPRE, plasma, ion, etc.).

Prior Art

When constructing systems and schemes for servicing a set of OS, similar to the one noted above, such a phenomenon as node line regression (RLN) can be used, which takes place for the orbits of almost any satellite (except polar ones), due to the non-centrality of the Earth's gravitational field. The angular velocity of the RLS Ω' ~ cos (i)/p ² , and in low orbits (p ~ 7000 km) reaches a noticeable value: about 4° per day at i ≈64° or less, and rapidly decreases with increasing orbit height.

This phenomenon is used when choosing SO orbits (MTA with service spacecraft) - so that their inclinations are the same or close to the OS orbit inclination, and the focal parameters p of the OS orbits differ from those for the SO orbits, which leads to the alignment of the OS and SO orbital planes. due to the different speed of the radar of those and those.

This is reflected, for example, in patents RU 2688120 C1, RU 2220886 C2, US 8016240 B2 and allows you to significantly reduce the cost of the characteristic speed (HSC) for CO maneuvers. However, the process of combining the planes of the OS and CO orbits can take a lot of time (which reduces the efficiency of service and increases the time of unsatisfactory operation of the satellite system).

It is known to place auxiliary or reserve satellites on synchronously precessing ones (with the same angular velocity Ω' as the orbits of the serviced (main) satellites), but differing in one or another orbital elements (eccentricity, perigee position, inclination): US 5999127 A, US 6892986 B2 etc.

Such techniques increase the efficiency (flexibility) of the functioning of the system of main satellites, but do not affect the maintenance of satellites with the help of SO moving from their orbits to OS orbits.

Closest to the proposed inventions are the space service system (SOS) and the method of its operation, described in US Pat.[2] RU 2535760 C1.

The COS [2] contains satellite service facilities (SO) located on one or more basing orbits corresponding to their service areas (for example, the above groups of orbits) and delivered from these orbits to the serviced satellites (OS). The method of operation of the CBS [2] includes the placement of CO in one or more orbits and delivery from these orbits to the OS.

The disadvantage of the known CBS and the method [2] is that they have not developed methods for controlling the movement of CO, which can reduce the time of delivery of CO to the OS while limiting the costs of the HSC for the maneuvers of the delivery vehicles (MTA).

Essence of inventions

The objective of the proposed inventions is to eliminate the above disadvantage by developing a CBS and a method for its operation, which allow servicing objects in orbits that form a spatial configuration, with reduced delivery times for CO to the OS and while limiting the costs of the CSC for the maneuvers of the delivery vehicles.

The technical result is to increase the efficiency of maintenance of the OS without a significant increase in the required costs of the HSC for the maneuvers of the delivery vehicles.

The solution of the problem, with obtaining the specified technical result, is achieved by the fact that the SBS containing the CO of satellites located in one or more basing orbits corresponding to their service areas, and delivered from these orbits to the OS, is equipped with base SC (BCA) in the basing orbits, including payload modules (PN) and modular MTAs for moving CO between the USS and OS, means for receiving and processing OS status and operation data (DSF) and transmitting the results of processing the DPF to USS, equipped with systems for receiving and generating CO composition based on these results , MTA configuration and optimal, taking into account the differences in the regression velocities of the OS orbit nodes and home orbits, trajectories of CO delivery to the OS, and one or more home orbits are selected with a focal parameter (p') as small as possible of the characteristic focal parameter (p) of the orbits satellites from the respective service areas, and with an inclination (i') close to the characteristic inclination (i) of satellite orbits from the same service areas.

Options are possible when the means for receiving and processing DFS OS are located at ground stations that have communication channels with the BKA and / or MTA, or when these tools are installed on the BKA and / or MTA, and the MTA is equipped with means for changing its configuration.

Modular MTA can include unified, docked with each other propulsion stages with chemical, for example, liquid rocket engines (LRE) and electric rocket, for example, stationary plasma (SPD) engines.

Preferably, the home orbits are low earth orbits served by reusable aerospace transport vehicles with reentry stages.

The solution of the problem, with obtaining the specified technical result, is also achieved by the fact that in the method of functioning of the CBS, including the placement of CO in one or more orbits of basing and the delivery from these orbits to the OS - UAVs and modular MTAs are brought to one or more orbits of the basing, periodically deliver there, the modules PN, on the basis of the transmitted results of processing the OS DPF, determine the probable timing, type and sequence of OS service, which is optimal, for example, according to the minimum HSC with the current forecast of the time of delivery of CO to the OS, the primary trajectory of the MTA in the plane of its osculating orbit, coinciding at the start of the MTA with the plane of the home orbit, the composition of the CO is formed from the set of the MO modules required for servicing, the MTA configuration in the form of the indicated propulsion stages, refueled from the BKA in accordance with the specified primary MTA trajectory and docked with the MO modules, after which the MTA is transferred to the specified trajectory, periodically updated forecast of delivery time of CO to O C and the meeting point, correcting the current optimal trajectory of the MTA, during movement along which the focal parameter of the MTA orbit is changed from the initial (p') to the final (close to p) according to the law that ensures the maximum alignment of the planes of the MTA orbits and OS due to the differences in the regression rates of the lines of the nodes of these orbits, correcting, if necessary, the inclination (i') of the MTA orbit.

If it is impossible to sequentially move the MTA between several OS along the current optimal trajectory, the MTA is reconfigured with re-docking of the ST and stages into two or more MTA configurations, their separation and movement along different optimal trajectories from the separation point to the corresponding OS, controlling the movement of the MTA on each of these trajectories as above.

Mostly, when the MTA moves along the current optimal trajectory, electric rocket engines are used, for example, SPT engines, and if there is a shortage of time to service some OS (as a result of a forecast or actual failure of the OS), a stage with a rocket engine is used.

The return of the MTA to the base orbit, in the preferred embodiment, is carried out using an electric rocket, for example, a SPT engine.

List of figures

The essence of the invention is illustrated by the following detailed description of examples of their implementation with the accompanying drawings, which show:

Fig. 1 - the main fragments of the proposed CBS and the implementation features of the proposed method for servicing the OS system;

Fig. 2 is a diagram of the construction and implementation of MTA motion control according to the proposed method.

Disclosure and examples of the implementation of the inventions

Satellite systems located in low orbits: up to the lower altitude boundary of the inner radiation belt ~ 500 km, have a limited view of the Earth and the surrounding space, and their maintenance is difficult due to their large required number, a large variety of orbits, and significant costs of CSOs for interorbital maneuvers, and as a consequence - the rapid accumulation of space debris. Currently, there is a tendency to use many pico- and nano-satellites (such as Cubesat), the maintenance of which is reasonably reduced to their timely elimination by their own means (direction into the atmosphere). There seems to be no need for special SBS in this near-Earth region (and could only lead to additional accumulation of various spacecraft and debris).

The areas between the inner and outer radiation belts (altitudes ≈6000 km and 12000 km) and above the conditional boundary of the outer belt (altitudes more than ≈18000 km) are favorable for the deployment of satellite systems there (such as navigation, communications and monitoring) - not only with from the point of view of radiation safety, but also for the intended purpose (wide fields of view, fewer required number of satellites, etc.). In these areas, multifunctional spacecraft (platforms) of significant power, developed modular architecture, etc. can be created. It is also expedient to concentrate the main activity of the KOS here (including from the point of view of the costs of the KhSK).

Thus, systems like GLONASS or GPS (and their combinations and modifications), as well as those located somewhat lower (at altitudes of ≈ 6000 ... OS systems).

Figure 1 shows a fragment of the serviced system, which contains OS 1 in orbits B. The planes of the orbits B are inclined to the plane of the equator C and distributed along it along the longitude of the ascending node Ω.

The proposed CBS contains SO satellites located in one or more low base orbits (b), for each of which its own service area can be allocated (for example, orbits of the same inclination i that are close in height). The lower the orbit b, the greater the rate of precession of its plane Ω' relative to the planes of the OS orbits, which is desirable.

Orbits b are based on USCs (of the type of orbital platforms or stations), on which SSs for OS 1 are formed from PN modules (PNs include a set of replaceable nodes, blocks, subsystems; stocks of working bodies for OS propulsion systems, STRs, etc. ). Orbits b are also parked modular MTA 2 (figure 1). MTAs are equipped with the necessary set of robotic tools for OS operations, and may also have the means to change their own configuration.

KOS is equipped with means for obtaining and processing data on the state and functioning (DSF) of the OS. These data are primarily telemetric data, but there may be other information, for example, the quality of images of onboard television cameras, failures of transmitted signals, deviations of orbits and external configuration of the OS observed from the Earth, etc.

The processing of the DPF is aimed at obtaining a forecast about the further functioning of OS systems and possible failures. It can be carried out at ground stations or on the UAV and be carried out in conjunction with known (embedded in the OS control systems) strategies and operation algorithms (STAF). These STAFs prescribe the restructuring of the operation of OS systems in the event of certain failures (for example, in the event of a breakdown of the turn drives, the SAs change the mode of operation of the attitude control system of the entire spacecraft). The results of processing the DPF together with the STAF (if they are obtained outside the BKA) are transmitted to the BKA, where operation models (MF) of the satellites are developed. Based on the MF _j of each j-th OS, a forecast of time (t* _j ) and the type of critical (requiring maintenance) failure of this j-th OS, as well as its orbital position R _j (t* _j ) at the moment of failure should be obtained.

This is illustrated in figure 2, which also shows that for the development of MF _j can be used data from the bank of accumulated information (BNI) - a certain library obtained over a long period and systematized information (for example, statistics) about the operation and failures of various spacecraft in different operating conditions .

Information, including DPF, is received by terminals 3 (on the ground or on the BKA) and further processed (filtered, ranked, etc.).

Based on the MF _j model and the forecast R _j (t* _j ) for the j-th OS, the optimal (piecewise-optimal) control U ^k _j (t, P _i ) for the appropriate i-th MTA from the corresponding service areas. In this case, the initial conditions for each section (piece) of the trajectory are the position R _i (t ^- ) and the speed V _i (t ^- ) of the MTA at the time t ^- the last forecast is received, and the final conditions ^are the forecast R _j (t * _j ) and the corresponding orbital velocity V _j (t* _j ). The control parameters P _i may be updated with each prediction.

Control optimization can each time be carried out according to the minimum HSC for a given movement time (t* - t ^- ), provided that the MTA trajectory (a) is in the plane (A) of its osculating orbit, which has the current focal parameter p'(t) (Fig.1 ). However, other, in particular, probabilistic optimality criteria are also possible.

Upon receipt of the first forecast - by the time the MTA starts from orbit b - the composition of the CO is determined in the form of OS modules for the OS (the possibility of this, obviously, implies, due to the inevitable inaccuracy of the forecast, a high level of unification and modularity of all OS nodes and systems), and also - a set of MTA stages with chemical (LPRE) and / or electric rocket (SPD or ion) engines.

Forecasts for several (m) OS can "fit" into a single (piecewise-optimal) trajectory of the MTA - sequentially from one OS to another. In this case, the PN in the home orbit is formed for all these OS, and the control is "stitched" from pieces U ^k _i , (t, Р _i ), where i=i ₁ , i ₂ , ... i _m-1 (indices are marked, in in particular, a change in the structure of the MTA and PN at each service).

Control data (control commands, directives or programs) are transmitted to MTA 2 via terminals 4 (figure 2).

In the process of refining the forecasts, the sequential movement of the MTA between several TSs may become unfeasible (due to the restrictions on the delivery time of CO for a given stock of CCS). Then the MTA is reconfigured with reconnection of the PN modules and stages into two (or more) configurations of the MTA and PN with their separation, which is shown in figure 1 as a branching of the trajectory (a) at point (c) into separate trajectories a ₁ and a ₂ MTA stages with parts of the ST (all trajectories are conditionally shown as flat, but in fact they are, of course, spatial, since plane A precesses). Control on each trajectory a ₁ and a ₂ is based on the principles described above. In this case, on one of the trajectories a _i , the parameter p'(t) may decrease for some time (to increase Ω').

If the arrival of the MTA from the MO to the OS is expected before the next forecast, then the passive sections of the MTA flight trajectory are realized.

Parameters P, can take into account the above change in the structure of the MTA and MT: when separating parts of the MT (in the process of serving several OS) and when separating the stages of the MTA (in the case of a branching of the trajectory).

Since the forecast time will practically be at least 10-15 days (~ 10 ⁶ s), and the required CCS will be about 3000-4000 m/s, the required thrust-to-weight ratio v ≈ 0.003-0.004 m/s ² , which is an order of magnitude less than the standard thrust-to-weight ratio ( ratio of thrust to engine mass) n of such engines, such as, for example, SPD-230, 200, 140 models (Fakel Design Bureau), for which n ≈ 0.03-0.04 m / s ² , due to which the mass of engines will be only slightly more than 10% of the mass of MTA with PN. The specific impulse of these SPTs reaches 2000–3000 s.

Therefore, the use of such low-thrust engines is preferable, and the transition to the use of high-thrust engines (LRE) on the MTA is expedient only if the need arises (lack of time to service some OS). The return of the MTA to the home orbit is also carried out with the help of the SPT.

As for the prediction of OS failures, then, generally speaking, a rough approximation can be taken as the period of regular operation of the OS (for example, 10 years). A more accurate forecast is obtained by monitoring the consumption of the working fluid for correction and orientation and / or degradation of solar panels (by their output power). For forecasts for other OS systems, based on the DPF, much more extensive information and its in-depth (computer) analysis are required. Random breakdowns (for example, in the event of a breakdown by a micrometeorite) can be taken into account when developing the STAF, with estimates of the time of emergency operation of OS systems - for the most probable range of such breakdowns.

A special approach to the design of a spacecraft (OS) is also possible, when the operating times of all its systems and nodes are strictly limited (and coordinated, for example, with the range of tasks of a given spacecraft) - which can be economically feasible within the framework of a combined satellite system and COS.

Industrial Applicability

Implementation of the proposed inventions does not require fundamentally new theoretical concepts and developments in the field of rocket and space technology; known means and methods for constructing space systems and controlling them can be used here.

Claims (8)

1. A space service system containing service facilities (SO) of satellites located in one or more basing orbits corresponding to their service areas and delivered from these orbits to serviced satellites (OS), characterized in that it is equipped with basic space vehicles (BSV) in basing orbits, including payload modules (PN) and modular interorbital transport vehicles (MTA) for moving SO between the USS and OS, means for receiving and processing data on the status and operation (DSF) of OS and transmitting the results of processing the DSF to USS, equipped with systems based on these results, the CO composition, MTA configuration and optimal, taking into account the differences in the regression rates of the OS orbit node lines and home orbits, SO delivery trajectories to the OS, and one or more home orbits are selected with a focal parameter (p'), as far as possibly smaller than the characteristic focal parameter (p) of the orbits of satellites from the corresponding service areas, and with an inclination (i') close to the characteristic inclination (i) of satellite orbits from the same service areas. 2. The space system according to claim 1, characterized in that the means for receiving and processing DFS OS are located at ground stations that have communication channels with the BKA and / or MTA, or are installed on the BKA and / or MTA, and the MTA is equipped with means for changing its configuration . 3. The space system according to claim 1 or 2, characterized in that modular MTAs include unified, interlocking propulsion stages with chemical, for example, liquid-propellant rocket engines (LRE) and electric rocket, for example, stationary plasma engines (SPD) . 4. The space system according to claim 1, characterized in that the home orbits are low earth orbits served by reusable aerospace transport spacecraft with return stages. 5. The method of operation of the space service system according to any one of paragraphs. 1-4, which includes the placement of SO in one or more basing orbits and delivery from these orbits to the OS, characterized in that USC and modular MTAs are placed in one or more basing orbits, the modules of the PN are periodically delivered there, based on the transmitted results of processing the OS DPF determine the probable timing, type and sequence of maintenance of the OS, optimal, for example, in terms of the minimum cost of the characteristic velocity (HSC) with the current forecast of the time of delivery of CO to the OS, the primary trajectory of the MTA in the plane of its osculating orbit, which coincides with the plane of the home orbit at the start of the MTA, form SO composition from the set of MO modules required for maintenance, MTA configuration in the form of the specified propulsion stages, refueled from the BKA in accordance with the specified MTA primary trajectory and docked with the OS modules, after which the MTA is transferred to the specified trajectory, periodically updating the forecast of the CO delivery time to the OS and the meeting point, correcting the current optimal trajectory of the MTA, when moving at which the focal parameter of the MTA orbit is changed from the initial (p') to the final (close to p) according to the law that ensures the maximum alignment of the planes of the orbits of the MTA and OS at the predicted time of delivery of the ST to the OS due to differences in the regression rates of the lines of the nodes of these orbits, correcting at necessary inclination (i') of the MTA orbit. 6. The method according to claim 5, characterized in that if it becomes impossible to sequentially move the MTA between several OS along the current optimal trajectory, the MTA is reconfigured with reconnection of the ST and stages into two or more MTA configurations, their separation and movement along different optimal trajectories from the point separation to the corresponding OS, controlling the movement of the MTA on each of these trajectories, as indicated above. 7. The method according to claim 5 or 6, characterized in that when the MTA moves along the current optimal trajectory, electric rocket engines, for example, SPT engines, are used, and if there is a shortage of time to service some OS, as a result of a forecast or actual failure of the OS, they use stage with LRE. 8. The method according to any one of paragraphs. 5-7, characterized in that the MTA is returned to the home orbit using an electric rocket, for example, a SPT engine.

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