RU2480384C2 - Method of placing space apparatus in geostationary orbit and device to this end - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to aerospace engineering. Proposed method consists in placing spacecraft in point of near-Earth space with preset latitude and altitude so that angular velocity of spacecraft spinning complies with that of the Earth and maintaining it at said point by continuously operated engine with thrust equal to net of Earth attraction force and centrifugal force acting at spacecraft in opposite direction. Vector of thrust force cross the center of spacecraft gravity. Proposed device is composed of spacecraft comprising control system, orientation system, payload unit, and service systems. It is equipped with continuous-operation engine at swinging suspension electrically connected with control system of spacecraft center of gravity and system for provision of anticollineation of engine thrust vector with net of Earth attraction force and centrifugal force acting at spacecraft Continuous-operation engine is equipped with system for thrust throttling in the range of said net force.

EFFECT: expanded satellite geostationary zone.

2 cl, 6 dwg

Description

The invention relates to the field of rocket and space technology and can be used to place spacecraft in a geostationary orbit in a plane parallel to the equatorial, but not coinciding with it.

The property of spacecraft launched into a geostationary orbit in the equatorial plane at a distance of 42164 km (35786 km from the Earth’s surface), on which the spacecraft revolves around the planet with an angular velocity equal to the angular velocity of the Earth’s rotation around the axis, and is constantly above one and the same the same point on the earth's surface, is widely used in world cosmonautics.

The practice of operating geostationary spacecraft has confirmed the effectiveness of their application for solving a wide range of tasks: observation, communication, control and others.

The main advantages of the geostationary orbit (GSO) include the immobility of the satellite relative to the terrestrial consumer, as well as the significant height of its position, which allows serving large areas (up to 30% of the surface of the globe with one satellite).

The methods for launching spacecraft (SC) at the GSO and their placement have been worked out; devices for implementing these methods are known.

For example, patent No. 2254265 C2, B64C 1/00, B64C 1/10 “The method of launching artificial satellites as the main and associated payloads on the geostationary orbit and a device for its implementation”, authors Medvedev A.A., Nedayvoda A.K. et al., patent holder of the Federal State Unitary Enterprise “State Space Research and Production Center named after M.V. Khrunicheva. "

However, the operating conditions of this type of satellite over time are becoming more complicated. The total number of spacecraft in a single geostationary orbit lying in the plane of the Earth's equator is constantly increasing. This leads to various problems, for example, mutual interference in the operation of airborne vehicles and problems of ensuring the safety of group flights. The problem is created by spacecraft that have exhausted their resources and have not been removed from the GSO to the burial zone.

The number of spacecraft that can be safely placed and operate efficiently in geostationary orbit is not unlimited.

GSO in the equatorial plane has two significant drawbacks:

- limited capacity of the frequency-orbital resource;

- low elevation angles in the middle and high latitudes, the inability to provide communication in the polar and polar regions.

The geostationary orbit is recognized by the world community as a common limited resource of mankind and its use is carried out by an international organization within the framework of international space law. Spacecraft deployment at GSO at the standing points is distributed and strictly controlled by an international organization.

The unique feature of the GSO has led to its rapid and intensive filling with spacecraft of national and international satellite communication systems and the exhaustion of its frequency-orbital resource. In total, since the launch of the first satellite on the GSO from 1964 to 2001. over 600 communication satellites for various purposes were launched at GSO. Currently, there are 407 active spacecraft at the GSO. Further deployment of new systems in this orbit involves a complex, lengthy and rather expensive process of coordination and coordination with national and international organizations.

Consequently, in the future, perhaps not so far, the inevitable problem of placing geostationary spacecraft outside the currently used and increasingly loaded geostationary orbit will arise.

Technical tasks related to reducing the severity of the problem of GSO congestion became relevant.

There is a fundamental possibility of the dispersal of geostationary satellites in the vicinity of the geostationary orbit.

So, for example, according to the application No. 93010797/09 dated 03/01/1993 Н04В 7/15, Senkevich V.P., Semenenko E.T., Sergeev V.E. “A method for placing satellite-based satellite relay systems in a geostationary orbit and a multifunctional platform for its implementation” it is proposed to expand the GSO area using tethered blocks rotating around a central spacecraft in a geostationary orbit in the equatorial plane.

Known patent of the Russian Federation 2058916 B64G 1/00 - a space station (CS) located on the GSO, containing several modules remote from each other, combined into an orbital complex by means of flexible connections and equipped with an energy source, means for converting and distributing energy and information flows, motion control and navigation, as well as receiving and transmitting equipment located on the orbital complex.

The disadvantages of the solution for this patent are the small resource of the COP, low maintainability and, accordingly, low efficiency due to the lack of the possibility of retrofitting the COP and building it with new devices.

According to the patent No. 2202499 C1 B64G 1/00, G1 / 10 of JSC RSC Energia named after S.P. The Queen “Space station, mainly in geostationary orbit” proposed a GSO space station containing basic modules, equipped with energy supply systems, motion and navigation control, propulsion systems, transmitting and receiving equipment, means for converting and distributing energy flows and combined through communications into an orbital complex . The prefabricated rod is oriented parallel to the earth's axis; there are means for capturing target satellites and installing them on the prefabricated rod.

The disadvantage of the proposed solutions for expanding the use of GSO in the equatorial plane is the need to create complex and expensive space stations that combine the constellation of target satellites.

Scientific and technical achievements in the field of ballistics allow finding new solutions in the construction of stable spacecraft motion trajectories.

For example, the spacecraft motion around a space body in a plane that does not pass through the center of mass of this space body is mastered. To do this, use the construction of a circular trajectory around the libration point located near the cosmic body. This makes it possible to construct an effective trajectory of the spacecraft transition from one cosmic body to another. For example, from the satellite of Jupiter Calisto to Ganymede, Europe, Io, and in the opposite direction, from the satellite of Io to Europe, then Ganymede, then to Calisto. Such a scheme was called the "Lagrange" staircase.

However, calculations showed that the use of libration points near the Earth for the purpose of expanding the geostationary region is impossible.

Theoretical predictions about the possibility of placing a spacecraft in a non-Kapler orbit (NKO), or levited displaced orbit, made by the American physicist Robert Forward, were considered impossible due to a number of problems with the dynamic stability of the spacecraft.

Scientists at the Advanced Space Concepts Laboratory, Shahid Baig, and Colin MCinnes have proposed the NKO family, in which the spacecraft is above or below a fixed GSO point, equipped with a solar sail and located in complex non-linear motion, but does not lose the properties of geostationarity.

This proposal allows you to unload the GSO, but the area proposed for use by the family of these orbits is limited to above or below 50 km near the equatorial GSO.

To eliminate this drawback, a solution is proposed for emulating the characteristics of a satellite system on a GSO, that is, reproducing (emulating) the effect of the immobility of satellites relative to the Earth’s surface using satellites placed in elliptical synchronous orbits having the same inclination, eccentricities, perigee arguments, Greenwich longitudes of the ascending node and intervals between passages of successive satellites of this Greenwich longitude. For example, patent No. 2223205 С2 B64G 1/10, Н04В 7/185 CJSC Information Space Center “Severnaya Korona” “A system of satellites in elliptical orbits emulating the characteristics of a satellite system in geostationary orbit, containing an orbital constellation of artificial satellites placed in elliptically inclined orbits with a circulation period of about twelve hours, "the authors Viter V.V. and others.

This technical solution allows you to create the effect of the spacecraft hovering over a point on the Earth's surface in a non-equatorial plane.

However, the drawback of this solution is the need to create a complex and expensive complex of interconnected spacecraft communication systems and the need to launch them in strictly coordinated orbits.

In addition, when creating the effect of satellites freezing (essentially imaginary) due to the emulation of their characteristics, there is a time interval between the arrival of the spacecraft at the imaginary freezing point, which depends on the number of satellites in orbits that are involved in the emulation of the characteristics of a geostationary satellite. There are also restrictions on the height of the emulation point of the geostationary satellite, due to the fact that this point should be at the peak of the extended orbits of the spacecraft, which does not allow the use of low altitudes.

The technical solution according to patent No. 2223205 is selected as a prototype.

The aim of the proposed method is to expand the possibility of geostationary motion of spacecraft not only in the equatorial plane, but also in a non-equatorial plane parallel to it, at any given geographical latitude.

According to the proposed method, it is technically feasible to "suspend" the SC over any point of the globe at any height for a limited time due to the consumption of its mass or supply of energy from the outside.

For such devices, there are already a number of urgent practical problems. In all countries of the world, the number of dynamic situations that require monitoring, control, and often the management of specific types of actions is increasing every year.

In peacetime, these are extreme and emergency situations of natural and man-made origin, mainly in the field of ecology. In such situations, the tasks of the operational organization and implementation of continuous monitoring, communication and control for a limited time in various areas of the land surface and water basins are very relevant. Especially valuable is the use of such spacecraft in hard-to-reach areas and in areas where conventional means of communication are out of order, where ground and aviation means quickly organize the collection of information, communication and control are practically impossible.

All these situations differ in many ways: by their importance, danger, rate of development and, as a consequence of this, by the required frequency of updating information and its required content. But, due to their dynamism, in most cases continuous monitoring of given areas is required for a limited time.

To collect, process and transmit information in the above and other situations, various ground-based stationary and mobile monitoring and control points are used, as well as aircraft: helicopters, airplanes, artificial Earth satellites, differing in their capabilities, limitations of application conditions, technical and economic characteristics . It is also possible to use some other known types of aircraft, for example, surface and submarines, ballistic missiles, airships and other means.

However, according to the tactical, technical and economic parameters, monitoring and communication systems using space means for solving most problems have an undeniable advantage over all other means [TS Kelso. “Fundamentals of the geostationary orbit”].

In complex, rapidly changing regional and local situations, it is more realistic to rely on the successful use of single controlled satellites with a circulation period equal to the period of the Earth's revolution around its axis, quickly launched into a given area for a limited period of time, commensurate with the duration of the controlled situation or controlled operation. Studies of the flight altitude range of approximately 50-100 km are also noteworthy.

The essence of the proposed method of placing the spacecraft on the GSO in a non-equatorial plane is as follows.

The spacecraft is brought to a point in near-Earth space with a given geographical latitude and height above the Earth's surface so that the angular velocity of rotation of the spacecraft coincides with the angular velocity of rotation of the Earth and support its movement at this point with the help of a constantly operating engine with a thrust equal to the resultant from the force of attraction Earth and the centrifugal force acting on the spacecraft, and opposite in direction, with the thrust vector passing through the center of mass of the spacecraft.

The proposed method can be implemented in various design options.

For example, a device for implementing a method of placing a spacecraft in a geostationary orbit is performed in the form of a spacecraft containing a control system, an orientation system, a payload unit, service systems with a continuous propulsion system on a swinging suspension, electrically connected to the control center of mass of the spacecraft, and a system for ensuring anticollinearity of a vector of a thrust force of a permanent-acting engine to a vector of the resulting force on the Earth's gravity and prices robezhnoy forces acting on the spacecraft, and the engine is equipped with continuous throttling traction range change value of the resultant force of the Earth's gravity and the centrifugal force acting on the spacecraft.

According to the proposed method, the spacecraft is launched by a launch vehicle to a given point in outer space both from a circular orbit and from a ballistic trajectory. After the spacecraft’s propulsion block is turned on, the radius of the spacecraft’s circular orbit and the angular velocity of the spacecraft’s rotation are adjusted so that the condition of geostationary motion is observed above a given point on the earth’s surface. In this case, the angular velocity of rotation of the Earth and the spacecraft coincide, and the spacecraft, as it were, hangs over the underlying point of the earth's surface.

Maintaining an aircraft at a given height above a given point on the earth's surface outside the equatorial geostationary orbit requires constant fuel consumption. However, the ability to place the device in the most convenient point for operation or a limited area significantly increases the efficiency of its use, in particular, allows you to use it in the middle and even high geographical latitudes.

After turning off the engine holding the satellite over a given point of the Earth’s surface, this satellite, if certain conditions are met, can remain in the orbit of a standard satellite, continue flying without additional fuel costs and then again go into hovering mode over a given point of the Earth’s surface.

The proposed method opens up an area of new possibilities for the types of spacecraft maneuvers and the characteristics of the tasks they solve.

The essence of the proposed method is illustrated by the following figures.

Figure 1 - the conclusion of the spacecraft to the point of near-Earth space with a given geographical latitude and height above the surface of the Earth.

Figure 2 is a design diagram of the forces acting on a nonequatorial geostationary spacecraft.

Figure 3 - the mutual dependence of the lateral deviation from the plane of the equator and the geocentric radius of the orbit of the non-equatorial geostationary spacecraft at various accelerations J.

Figure 4 - lines of equal values of the accelerations that hold the geostationary spacecraft in a non-equatorial orbit at different geocentric radii r and geographical latitudes.

Figure 5 - the duration of maintaining the mode of dependence on the relative mass flow of the spacecraft when the satellite is displaced from the equator in the meridional direction by 10 km.

Specific thrust impulses: I ₁ = 3 km / s (chemical fuel), I ₂ = 10 km / s (ERE), I ₃ = 25 km / s, I ₄ = 50 km / s (ERE, NRE).

6 is a diagram of a spacecraft installed in a non-equatorial geostationary orbit.

Ballistic calculations to assess the possibilities of creating non-equatorial geostationary spacecraft show the following results.

If a force is applied to a satellite moving in the plane of the equator in a plane passing through the axis of rotation of the Earth, the equilibrium of movement will be violated, and the satellite will go on a trajectory that lies outside the plane of the equator. Consider this situation, provided that the satellite continues to move at the same angular velocity relative to the axis of rotation of the Earth (figure 1).

In figure 2: G is the gravity of the satellite by the Earth; F is centrifugal force

P 'is their resultant, φ is the geographical latitude of the satellite hovering point.

In order to keep the satellite in uniform circular motion in a new, displaced plane of the orbit, a force P 'equal to P in magnitude and opposite to it in direction should be applied to it.

The value of P = P 'is determined from the equation:

This force should tell the satellite the acceleration J equal to:

where r = R ₃ + H is the geocentric radius of the orbit of the non-equatorial geostationary satellite, H is its altitude, R ₃ is the radius of the Earth.

Using these equations, we can calculate the dependence of the parameters of the displaced circular orbit of the spacecraft on the magnitude of the acceleration applied to the satellite. A graph of this dependence for a small neighborhood of the geostationary orbit is shown in Fig. 4, for other circular non-equatorial geostationary orbits, in Fig. 3.

Figure 3 shows that to offset the orbital plane of the geostationary satellite 100 km from the equatorial plane, it is required to apply an acceleration J of the order of 0.05 cm / sec ² to the satellite.

Let us evaluate the possible duration of maintaining a non-equatorial geostationary spacecraft at various geographical latitudes and at various altitudes above the Earth.

The total velocity impulse ΔV = J * ΔT spent on maintaining such a satellite at a geographical latitude φ at a height H during the time interval ΔT is determined from the formula:

where: g ₀ R _beats - specific impulse,

m is the initial mass of the satellite,

Δm is the mass flow rate of the satellite,

Δm / m is the relative mass flow rate of the satellite.

Using this formula, the dependence of the duration of the maintenance of the mode of dependence on the relative mass flow rate of the spacecraft at different satellite offsets from the equator in the meridional direction and at different specific pulses can be determined. The calculation results are shown in figure 5.

Calculations show that near the equatorial geostationary orbit, the maintenance of non-equatorial geostationary spacecraft is possible even with the use of modern chemical fuels for several months at a cost of 10 to 20% of their initial mass. For medium geographical latitudes and altitudes from 30 to 50 thousand kilometers, these terms are reduced by an order of magnitude.

At present, electroreactive engines already exist and are used on equatorial geostationary spacecraft. Their application can significantly improve the technical characteristics of non-equatorial geostationary spacecraft.

The device KA 1 (Fig.6) for implementing the proposed method includes a unit 2 for bringing it to a point in near-Earth space with a given geographical latitude and height above the Earth's surface, which contains a propulsion system with the necessary supply of fuel components, as well as the corresponding service systems.

The design of the non-equatorial geostationary spacecraft provides a permanent-drive engine 3 on a swinging suspension 4 containing a plug for placing a permanent-drive engine with electric motors electrically connected to the control center of mass of the spacecraft 5 and controlled in such a way that the force action vector constantly passes through the center of mass of the spacecraft Ts _m 0.5 using a deviation at an angle α.

The spacecraft center of mass control system includes software for calculating the position of the spacecraft's center of mass and calculating data for commands to the swinging motors, entered into the onboard processor of the control system and acceleration sensors spaced as far as possible into the spacecraft body.

The area of change of the center of mass of the spacecraft 6 during the flight is inside the swing angle of the suspension, as a condition for ensuring stable motion of the spacecraft.

The system for ensuring anticollinearity (opposite direction) of the thrust vector of a continuous-acting engine to the vector of the resulting force from the Earth's gravity and centrifugal forces acting on the spacecraft includes acceleration sensors electrically connected to the onboard processor of the control system, which provides the calculation of the required instantaneous value of the engine thrust continuous action and its action vector.

The calculated values are converted into executive commands for the spacecraft orientation system and the throttle system of the continuous-acting engine.

The throttle system of a continuous-acting engine provides a change in the thrust force in a given range of values, which is equal to or greater than the range of change in the magnitude of the resulting force on the Earth's gravity and centrifugal forces acting on the spacecraft, and includes, for example, for an engine with chemical components, an electrovalve in the feed system of fuel components, connected electrically to the system for ensuring anticollinearity of the vector of the thrust force of a continuous-acting engine to the vector of the resulting force from oozes attraction of the Earth and of the centrifugal forces acting on the spacecraft.

The spacecraft carries a payload of 7 to solve functional problems. The spacecraft is equipped with an energy source (stock of fuel components for a chemical propulsion system) 8, a control system 9, and other necessary service systems 10. The spacecraft can have a docking unit 11 with the spacecraft - a fuel tanker to increase the active life.

Technical and economic efficiency of the proposed method is determined by:

in assessing the economic efficiency of solving the problems of observation and communication at a given point on the earth's surface in the implementation of a specific space complex;

when evaluating the efficiency of GSO unloading due to the expansion of the capabilities of the geostationary method of movement at different latitudes using the proposed spacecraft device.

Claims (2)

1. The method of placing the spacecraft in a geostationary orbit in a non-equatorial plane, characterized in that the spacecraft is brought to a point in near-Earth space with a given geographical latitude and height above the Earth's surface so that the angular velocity of rotation of the spacecraft coincides with the angular velocity of rotation of the Earth, and support its movement at this point with the help of a constantly operating engine with a thrust equal to the resultant from the Earth's gravity and centrifugal forces acting on space s device, and the opposite in direction, and the vector thrust passes through the center of mass of the spacecraft. 2. A device for implementing the method of placing a spacecraft in a geostationary orbit, made in the form of a spacecraft containing a control system, an orientation system, a payload unit, service systems, characterized in that it is equipped with a constant-current engine on a swinging suspension, electrically connected to the system control of the center of mass of the spacecraft and with a system for ensuring anticollinearity of the vector of the thrust force of a continuous-acting engine to the vector of the resulting force from the force of attraction Earth and the centrifugal force acting on the spacecraft, and the permanent engine is equipped with a throttling system of the thrust in the range of variation of the value of this resulting force.

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