RU2791518C1 - Method for removing defunct space vehicles from a geostationary orbit - Google Patents

Abstract

FIELD: cosmonautics.

SUBSTANCE: invention relates to clearing the near-Earth space from space debris. Proposed method considers that, when a space vehicle (SV) is being removed from a geostationary orbit (GSO), it may leave the area of visibility from ground-based stations. In order to eliminate the possibility thereof, an SV-free longitude section of the GSO with a width of at least 0.2° is selected in the east of the SV retention area. Said section is distanced from the retention area by longitude, wherein the distance allows increasing the SV flight altitude to the minimum height of the burial orbit and calculating strategies for transporting the SV to the section followed by removing the SV therefrom to the burial orbit.

EFFECT: fully controlled removal of an SV to the burial orbit when there are limitations for the areas of visibility of the SV from ground-based stations with command and measurement communication systems.

1 cl, 1 dwg

Description

The invention relates to the field of space technology, namely, to methods for cleaning near-Earth space from space debris (SM).

Due to the severity of the problem of space debris, in 2003, on behalf of the UN Committee on the Peaceful Uses of Outer Space (COPUOS), the Inter-Agency Coordinating Committee on Space Space prepared, and in 2007 the UN General Assembly approved a list of measures aimed at limiting man-made space debris. The proposals include a 25-year limit on the maximum lifetime of depleted low-orbit spacecraft and the transfer of geostationary spacecraft to disposal orbits.

The National Standard of the Russian Federation [1] (Russian Federation GOST R 52925-2018. Space technology products. General requirements for space vehicles to limit technogenic clogging of near-Earth space), paragraph 5.2, prescribes to prevent the formation of space debris during regular operations of space vehicles (Sr) and to prevent collisions KSR in orbit. According to paragraph 5.3, the requirements of this standard for CSR should be included in the TTZ (TOR) for newly created and modernized CSR.

A withdrawal scheme based on the general requirements of the above standard was adopted as a prototype. The regulation regarding the removal from the geostationary orbit (GSO) of spacecraft (SC) that have completed their active life, as a state of the art, is the following set of operations in a natural order:

1. Work to eliminate the eccentricity of the orbit, if it exceeds the allowable value for the spacecraft to be in the working area of containment (OCA).

The permissible value of the eccentricity on the GSO is not more than 0.0006 for the OUD ±0.1 ⁰ relative to the working standing point, and 0.0003 - for the OUD ±0.05 ⁰ . This item can only take place in emergency situations with the spacecraft, since the operating eccentricity is an order of magnitude, that is, negligible compared to the allowable for the disposal orbit.

2. Control of the guaranteed remnants of the working body of the spacecraft orbit correction system to ensure the withdrawal from the GSO.

3. Calculation of the minimum duration of the operation of the propulsion system (PS) to ensure the insertion into the disposal orbit above the GSO according to [1] p. 5 and [2] (K. Erike "Space flight", vol. II, part 1, p. 388) according to the formula:

where τ - total duration of operation of the remote control, s;

C _R - solar radiation pressure coefficient, from 1 to 2 kg/m;

A/m is the ratio of the cross-sectional area of the spacecraft to its mass after the termination of regular operation and passivation, m ² /kg;

μ is the gravitational parameter of the Earth, km ³ /s ² ;

a _st - semi-major axis of GSO, km;

V is the transversal velocity of the spacecraft in the GEO, km/s;

a - reliable acceleration from the operation of the PS, km/s ² .

The factor in square brackets is the nominal excess [1] of the perigee height of the disposal orbit over the GSO height, km, an approximating function, the first and second terms of which are not consistent in terms of the unit of measurement. But - such a standard [1].

4. Selecting the start time of the withdrawal based on the fact that for half a day before the end of the operation, the SC will be in the region of either the apogee of the orbit, or one of the focal points where the change in eccentricity is zero or minimal. In general, according to [1], the time of the start of the drift can be arbitrary, since the tolerance for the final eccentricity of the disposal orbit (0.003) is quite large, and the maximum change in the eccentricity for the entire time of the drift is no more than 0.0003.

5. Carrying out a slip correction.

At the estimated time, the remote control of the correction system is turned on.

6. Measurement of current navigation parameters (ITNP) - radio control of the withdrawal orbit.

The parameters of the current orbit of the spacecraft and the actual acceleration from the operation of the PS are determined.

ITNP is carried out in a full (regular) cycle at a one-and-a-half-day interval, depending on the number of ground stations involved.

7. If necessary, repeat paragraph 3, where instead of the term 235 km there is a negative difference in the excess of the height of the perigee of the current orbit and the height of the perigee of the disposal orbit over the height of the GSO.

8. ITNP.

The prototype has a significant drawback. It does not in any way regulate the position of the spacecraft on the GEO before the start of the final operations in the case when the OUD is located on the western border of the spacecraft (radio) visibility zone from the Earth. After all, according to the regulations, with an actual thrust of 0.083 N, it takes from 6 to 9 days to take a spacecraft with a mass of 4000 kg into a disposal orbit. If you start from the OMA, the spacecraft will be 10 degrees west of the OMA and 20 degrees west of the OMA on the tenth day of the flight in 5-6 days after the main operation of the PS. Control over the implementation of the removal from the geostationary orbit of spacecraft that have ceased their active existence will be problematic or unfeasible.

The technical problem to be solved by the claimed invention is the withdrawal of a spacecraft with GSO that has ceased active existence into a disposal orbit in the presence of existing restrictions on the elevation angle of target designations for pointing ground antennas of command and measuring systems of ground stations.

The specified technical problem is solved by the method of removal of spacecraft that have ceased active existence from the geostationary orbit, including the control of the guaranteed remnants of the working body of the spacecraft orbit correction system to ensure the removal from the GSO, the calculation of the minimum duration of the PS operation to ensure the removal to the disposal orbit, the choice of the start time of the withdrawal, ITNP, which differ by the fact that in the east of the OUD a free high-altitude corridor is chosen with a width in longitude of at least 0.2 ⁰ at the estimated distance (Δ L ), degrees, determined from the ratio:

- минимальное (предлагается) превышение высоты перигея орбиты захоронения над высотой ГСО, км;Where

- minimum (proposed) excess of the perigee height of the disposal orbit over the GSO height, km;

τ is the total duration of the PS operation, days;

80 - dimensional coefficient, day⋅km/degree,

which allows to implement the transition of the spacecraft to the disposal orbit within the visibility zone from ground stations, determine the strategy for transferring the spacecraft to this corridor, according to this strategy, the acceleration correction is carried out, the control ITNP is carried out and the combined correction of deceleration in the east and acceleration in the west directions is carried out, the duration of which is in days determined by the formula:

- максимальная (установившаяся) скорость пассивного дрейфа в восточном направлении, градус/сут,Where

- maximum (steady) speed of passive drift in the east direction, degrees / day,

the combined correction is carried out so that the spacecraft, when crossing the nominal GSO, is in the region of the high-altitude corridor.

An altitude corridor is understood as an area in longitude on the GSO, free from any spacecraft in this orbit and designed to change the direction of the active drift of the spacecraft in longitude to the opposite.

In FIG. 1 shows a schematic diagram of the removal of a spacecraft with a GEO that has ceased active existence.

The following notation has been introduced:

1 - GSO;

2 - OUD;

3 - acceleration correction;

4 - ITNP;

5 - passive drift to the high-altitude corridor;

6 - high-rise corridor;

7 - combined correction of deceleration and acceleration;

8 - overclocking correction.

We present the derivation of formula (2).

Drift in longitude, for example, in a westerly direction, at GSO height 1 can be described as follows.

Let us determine what deviation of the period of revolution from the sidereal day is required for the drift rate of the mean (averaged per revolution) longitude to be one degree per day:

, где 360 - полный оборот, градусы; 86164,1 - период обращения, равный звездным суткам, с. То есть скорости дрейфа 1⁰/сут соответствует отклонение (ΔТ) по периоду обращения 240 с. Далее. Согласно [3] (К. Эрике «Космический полет», т. I, стр. 391):

, where 360 is a full turn, degrees; 86164.1 - period of revolution equal to sidereal days, s. That is, the drift velocity 1 ⁰ /day corresponds to the deviation (ΔТ) over the circulation period of 240 s. Further. According to [3] (K. Erike "Space flight", vol. I, p. 391):

where T is the orbital period of the spacecraft, s;

a _orb is the perigee radius of the SC orbit (strictly speaking, is the semi-major axis of the SC orbit), km.

After differentiation (4) and transition to increments, we will have:

, км,Where

, km,

or ΔT ≈ 3Δ a _orb . Divide the left and right sides of (5) by 240. Assuming ΔТ = 3Δ a _orb , we will have:

Left side (6) - drift velocity, degrees/day. Then active (taking into account the operation of the PS) movement (corrections of acceleration 3, deceleration and acceleration 7 and additional acceleration 8) and passive movement (drift 5, ITNP 4) with GSO 1 from EMA 2 to altitude corridor 6 and from the altitude corridor to the disposal orbit can be present in the following form:

- суммарная длительность работы ДУ, i = 1,2, …, n, когда орбита КА находился под ГСО, сут;Where

- total duration of PS operation, i = 1,2, …, n , when the spacecraft orbit was under GEO, days;

τ ₂ - the total duration of passive drift 5, including ITNP 4, when the spacecraft orbit was under the GSO, days;

- суммарная длительность работы ДУ, j = 1, …, k, когда орбита КА находится над ГСО, сут;

- total duration of PS operation, j = 1, …, k , when the spacecraft orbit is above the GSO, days;

τ ₄ is the duration of the passive drift at the intervals of ITNP 4, when the SC orbit is above the GSO, days,

и

берутся со своим знаком.and quantities

And

are taken with their sign.

The duration of the remote control is divided in half, because during the operation of the remote control there is a uniformly accelerated or uniformly slow movement along the longitude.

Equation (2) is a particular case of relation (7). In equation (2), the last term 2 is responsible for the control ITNP. In general, τ ₂ and τ ₄ in (7) are responsible for passive drift at the beginning when transferring to the high-altitude corridor and after acceleration (re-acceleration), therefore, longitude movements are strictly tied to initial deviations along the semi-major axis.

Equation (3) is a special case of equation (1) in the sense of (6).

The technical result of the invention is a fully controlled diversion of the spacecraft into a disposal orbit in the presence of objective restrictions on the areas of visibility of the spacecraft from ground stations with command and measurement communication systems.

Claims (15)

A method for removing spacecraft (SC) that have ceased active existence from a geostationary orbit (GSO), including monitoring the guaranteed remnants of the working body of the spacecraft orbit correction system to ensure its removal from the GSO, calculating the minimum duration of the propulsion system operation to ensure insertion into a disposal orbit, choosing the start time removal and measurement of current navigation parameters (ITNP), characterized in that in the east of the hold area in longitude, a free high-altitude corridor with a width in longitude of at least 0.2 ° is selected at the calculated angular distance (∆L, deg), determined from the ratio:

, Where

– minimum excess of the perigee height of the disposal orbit over the height of the GSO, km; τ is the total duration of the PS operation, days; C _R – solar radiation pressure coefficient, from 1 to 2 kg/m; A/m is the ratio of the spacecraft's cross-sectional area to its mass after the termination of regular operation and passivation, m ² /kg; 80 – dimensional coefficient, day⋅km/degree, which allows to implement the transfer of the spacecraft to the disposal orbit within the visibility zone from ground stations, determine the strategy for transferring the spacecraft to this corridor, according to this strategy, the acceleration correction is carried out, the control ITRP is carried out and the combined correction of deceleration in the eastern and acceleration in the west directions is carried out, the duration of which is determined by formula:

, Where

– maximum (steady) speed of passive drift in the east direction, degree/day; μ is the gravitational parameter of the Earth, km ³ /s ² ; a _st is the semi-major axis, GSO radius, km; V is the transversal velocity of the spacecraft in the GSO, km/s; a - reliable acceleration from the operation of the PS, km / s ² , moreover, the combined correction is carried out so that the spacecraft, when crossing the nominal GSO, is in the region of the high-altitude corridor.

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