EA029450B1 - Method for spacecraft microaccelerations evaluation - Google Patents

Abstract

The method is related to the field of space engineering, in particular, to methods for implementation of gravitation-sensitive processes. The objective of the invention is pre-flight evaluation of the design component of microaccelerations. The assessment is performed by means of ground tests of a spacecraft model. The technical result of the invention consists in provision of active monitoring of the microaccelerations level in the zone of process equipment location at an early stage of spacecraft designing. The economical effect of the invention consists in significant reduction of expenses for creation of new space systems possessing unique operational and technical characteristics due to replacement of a part of space flight tests for assessment of microaccelerations level by ground bench tests.

Description

The invention relates to the field of space technology, and in particular to methods for implementing gravity-sensitive processes.

There is a method for evaluating micro-accelerations in the orbital flight of a spacecraft (SV) (Nikitin SA, Polezhaev VI, Sazonov VV About measuring the quasistatic component of micro-accelerations on board a satellite with a convection sensor // Space Research. 2001, vol. 39, No. 2, pp. 179187), which consists in determining the component of microaccelerations by means of a convection sensor.

Also known is the closest way to estimate micro-accelerations at the stage of operation of a spacecraft (Sazonov V.V., Chebukov S.Yu., Abrashkin V.I., Kazakova A.E., Zaytsev A.S. Analysis of low-frequency micro-accelerations onboard the satellite PHOTON- 11 // Space Research. 2001, vol. 39, No. 4, pp. 419-435), consisting in the installation of tools for measuring micro-accelerations of Russian and foreign production.

The disadvantages of these methods are

failure of ultra-sensitive measuring equipment due to high starting overloads;

high cost of testing;

the inability to conduct active control of the level of micro accelerations.

The purpose of this invention is to develop a method for obtaining a pre-flight assessment of the level of microaccelerations, devoid of the above disadvantages.

To achieve this goal and overcome the drawbacks, it is proposed to carry out measurements under terrestrial conditions using any of the methods for creating a micro-acceleration field (drop towers, laboratory airplanes, centrifuges, etc.), while using the model of a spacecraft with an orientation engine and elastic elements, taking into account the property of scale invariance of the constructive component of micro accelerations, for which we introduce a generalized parameter, which is calculated by the formula

100

/ V

where m ₀ is the mass of the central body;

μι is the linear mass;

ίί is the length of the ΐth elastic element;

N is the number of elastic elements of the spacecraft,

then scale the spacecraft according to the generalized parameter ζ according to the law

where ζ0 is the value of the generalized parameter for a real spacecraft;

Ζί is the value of the generalized parameter for the spacecraft model at the ΐth iteration; K - scale factor of the generalized parameter, unchanged at each iteration of scaling,

simultaneously with the scaling of the spacecraft, to ensure the invariance of the angular accelerations of the evolution of the spacecraft around the center of mass when the motor is pulsed with orientation for the ΐ th iteration of scaling

- ε, = сш1

where ε ₀ - the value of the angular acceleration when you turn on the engine orientation for a real spacecraft;

ε, is the value of the angular acceleration for the spacecraft model at the ΐth iteration.

The proposed method is illustrated in the drawing, which presents a scheme for conducting tests in order to assess the constructive component of the micro-accelerations.

A design for implementing the method of estimating micro accelerations comprises a drop tower 1, an elevator 2 installed therein, an ultra-low pressure sealed chamber 3, a model KA 4 with an orientation engine model 5, a means of measuring micro accelerations 6 and a model of elastic elements KA 7.

The KA model 4 with the engine 5 and the elastic elements 7 must be made taking into account the property of scale invariance of the constructive component of micro accelerations. For this, a generic parameter is introduced.

^t <> + Σμ

where t0 is the mass of the central body;

μι is the linear mass;

ίί is the length of the ΐth elastic element;

(one)

- 1 029450

N is the number of elastic elements of the spacecraft.

We scale the spacecraft according to the generalized parameter ζ according to the law ζ. = k ' _: - ζ ₀

(2)

where ζ ₀ is the value of the generalized parameter for a real spacecraft;

ζ; - the value of the generalized parameter for the spacecraft model at the ιth iteration;

C - scale factor of the generalized parameter, unchanged at each iteration of scaling.

Simultaneously with the scaling of the spacecraft, we will ensure that the angular accelerations of the spacecraft evolution around the center of mass do not change when the engine of the 5th spacecraft is switched on with a pulse for the ιth iteration of scaling

_{εθ =} - sniffing!

where ε ₀ is the angular acceleration value when the engine is turned on for real spacecraft orientation;

£; - the value of the angular acceleration for the spacecraft model at the ιth iteration.

So you can achieve the immutability of the type of dependence of micro accelerations on time at some point of the spacecraft.

Thus, the proposed method allows to obtain the dependence of the constructive component of the field of micro-accelerations on time, compressed ί ² times along the time axis.

Tests are carried out as follows.

After the beginning of the fall of elevator 2 in the tower of fall 1, the orientation motor 5 is pulsed, which creates the angular acceleration required by formula (3). The KA 4 model begins to evolve around the center of mass in an ultralow pressure sealed chamber 3. The vibrations of the elastic elements 7 of the KA 4 model are excited. Measuring instruments 6 record the values of the generated micro accelerations.

The proposed method will allow to evaluate the constructive component of micro accelerations, to develop a set of measures to bring the level of micro accelerations in the area of placement of technological equipment in accordance with the requirements of the technical task and conduct active monitoring of this level at the design stage of the spacecraft.

Claims (2)

CLAIM A method for evaluating micro-accelerations of a spacecraft, which consists in obtaining micro-acceleration data using appropriate measurement tools, characterized in that measurements are made under terrestrial conditions using any of the methods for creating a micro-acceleration field, using a model of a spacecraft with an orientation engine and elastic elements , made in view of the property of scale invariance of the constructive component of micro accelerations, for which a generalized parameter is introduced, which is calculated by formula where m ₀ is the mass of the central body; C; - linear weight; one; - the length of the ιth elastic element; N is the number of elastic elements of the spacecraft, then the spacecraft is scaled according to the generalized parameter ζ according to the law Y · ₀ five where ζ ₀ is the value of the generalized parameter for a real spacecraft; ζ _; - the value of the generalized parameter for the model of the spacecraft at the ιth iteration; C - scale factor of the generalized parameter, unchanged at each iteration of the scaling, simultaneously with the scaling of the spacecraft, ensure the invariance of the angular accelerations of the evolution of the spacecraft around the center of mass with the pulse switching on of the orientation engine for the ιth iteration of scaling ε _Λ = 8, = ... = 8, = COPZ ( where ε ₀ - the value of the angular acceleration when you turn on the engine orientation for a real spacecraft; ε; - the value of the angular acceleration for the model of the spacecraft at the ιth iteration. - 2 029450