RU2770327C1 - Method for simulating pressure in a vacuum chamber during ground testing of spacecraft for operability - Google Patents

Abstract

FIELD: testing technology.

SUBSTANCE: invention relates to the field of testing technology, in particular, to ground-based verification of spacecraft (SC). A method for simulating the pressure in a vacuum chamber during a ground-based check of the spacecraft for operability is proposed, in which the spacecraft is placed in a vacuum chamber, it is evacuated and the spacecraft is checked for operability. The operability is checked when the equipment is switched on electrically. The pressure value of the spacecraft’s own external atmosphere is calculated depending on the altitude of the spacecraft’s working orbit. The value of the residual pressure in the vacuum chamber is assumed to be equal to the calculated value of the pressure of the spacecraft’s own external atmosphere. With an increase in the pressure of the spacecraft’s own external atmosphere in the vacuum chamber, during the testing of the spacecraft for operability, its value is maintained at a given level by increasing the performance of the vacuum pumping system.

EFFECT: increase in the reliability of the results of checking the spacecraft for operability is achieved.

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Description

The invention relates to the field of test engineering, in particular, to ground testing of spacecraft (SC) for operability under conditions close to the operation of a spacecraft in outer space, and can be used in those areas of technology where there are increased requirements for the conditions for conducting experimental studies in assessment of the operability of the spacecraft equipment.

A known method of testing the spacecraft for performance, which consists in installing the spacecraft in a vacuum chamber, evacuating the vacuum chamber using a vacuum system to a residual pressure and checking the spacecraft for performance (RF Patent RU No. 2302983 C1, Bull. No. 20, 20.07.2007 g ., IPC B64G 7/00 (2006.01)).

The closest in technical essence to the proposed invention is a method for simulating pressure in a vacuum chamber during ground testing of a spacecraft for performance, which consists in placing the spacecraft in a vacuum chamber, evacuating the vacuum chamber using a vacuum evacuation system to a residual pressure and checking the spacecraft for performance ( Andreychuk O.B., Malakhov N.N. Thermal tests of space vehicles. - M.: Mashinostroenie, 1982, p. 105). This method is taken as a prototype.

The disadvantage of the analog and the prototype is that in these methods, when checking the performance of the spacecraft, the effect on the residual pressure in the vacuum chamber of the spacecraft's own external atmosphere, which consists mainly of the products of gas emission of non-metallic structural materials of the spacecraft, as well as the gas emission of pneumatic systems of the spacecraft, is not taken into account, for example, low-thrust attitude thrusters located on the spacecraft and used for orientation and stabilization of its position in outer space. This influence manifests itself, for example, in the form of an increase in pressure in the vacuum chamber during the switching on of the spacecraft equipment and turning on the orientation thrusters. An increase in the residual pressure of the spacecraft's own external atmosphere is dangerous for the operating spacecraft equipment, which is critical to low vacuum, from the point of view of the possibility of high-voltage electrical breakdown. This is especially important to take into account when checking the operability of medium-class highly maneuverable aerospace vehicles operated in low orbits, since the gas flow regime with a decrease in rarefaction (increase in pressure) of the spacecraft's own external atmosphere can change from molecular to molecular-viscous or viscous.

The objective of the invention is to ensure the creation in the vacuum chamber of a residual pressure close to the pressure during the operation of the spacecraft in a working orbit.

The technical result of the invention is to increase the reliability of the results of testing the spacecraft for operability while simulating the natural conditions of operation of the spacecraft.

The technical result is achieved due to the fact that in the method of simulating pressure in a vacuum chamber during ground testing of the spacecraft for performance, which consists in placing the spacecraft in a vacuum chamber, evacuating the vacuum chamber to a residual pressure using a vacuum pumping system and checking the spacecraft for performance at electrical inclusions of the equipment included in its composition, while calculating the value of the pressure of the own external atmosphere of the spacecraft depending on the height of the working orbit of the spacecraft, the value of the residual pressure in the vacuum chamber is taken equal to the calculated value of the pressure of the own external atmosphere of the spacecraft, and with an increase in the pressure value of the own external atmosphere The spacecraft in the vacuum chamber, in the process of checking the spacecraft for operability, maintain its value at a given level by increasing the performance of the vacuum evacuation system.

When a spacecraft is flying in outer space, the space vacuum surrounding it plays the role of vacuum evacuation means with high productivity, obviously exceeding the productivity of evacuation means of vacuum chambers; Spacecraft in ground conditions in a vacuum chamber, the pressure of the own external atmosphere of the spacecraft will increase when the spacecraft equipment is turned on due to the limited capacity of the pumping means of vacuum chambers. Thus, when checking the operability of a spacecraft in a vacuum chamber, maintaining a given pressure of the spacecraft's own external atmosphere is possible only by increasing the productivity of the available vacuum pumping means of the vacuum chamber.

Compared with the prototype, the claimed technical solution makes it possible to increase the reliability of tests of the spacecraft when it is tested for performance by improving the simulation of the full-scale operating conditions of the spacecraft.

The proposed method is implemented as follows:

- place the spacecraft in a vacuum chamber, for example, in VK 600/300;

- the vacuum chamber is evacuated using a vacuum evacuation system (vacuum pumps, for example, Oerlikon Leybold RUTA WH7000/DV1200/G mechanical pumps, Edwards STP-iXA4506C high-vacuum turbomolecular pumps) to a residual pressure equal to the pressure of the spacecraft's own external atmosphere. The pressure of the spacecraft's own outer atmosphere is determined by calculation, depending on the height of the working orbit of the spacecraft, based on the measurement results previously obtained by research spacecraft. For example, in an orbit with a height of 300 to 400 km, the pressure will be from 10 ^-7 to 10 ^-8 mm Hg. Art., and the calculated pressure of the own external atmosphere around the spacecraft will be 2-3 orders of magnitude higher, that is, it will be from 10 ^-4 to 10 ^-5 mm Hg. Art. This vacuum is created during testing of the spacecraft in a vacuum chamber and is measured, for example, using a Televac SS-10 vacuum gauge;

- start checking the spacecraft for operability according to the flight program. During the check, electrical switching on of the equipment that is part of the spacecraft is carried out, during which the equipment and the spacecraft as a whole are heated. As a result of an increase in the spacecraft temperature, an intensive process of gas release of products of non-metallic structural materials used in the spacecraft begins, the pressure of the spacecraft’s own external atmosphere increases, and a change in the gas flow regime occurs both around the spacecraft and in unpressurized spacecraft compartments, which is quite dangerous for the operating spacecraft equipment from the point of view of view of the occurrence of high-voltage electrical breakdown;

- when the pressure of the spacecraft's own external atmosphere in the vacuum chamber increases in the process of testing the spacecraft for operability, its value is maintained at a given level, that is, the pressure of the spacecraft's own external atmosphere is reduced to a predetermined residual value by increasing the performance of the vacuum evacuation system of the vacuum chamber, for example, by connecting an additional high-vacuum cryogenic pump HSRAG VELCO630 with high capacity: up to 45000 l/s;

- continue checking the spacecraft for operability according to the flight program until its completion.

Implementation example.

The experimental spacecraft was placed in a vacuum chamber and the vacuum chamber was evacuated to a calculated pressure of 1⋅10 ^-4 mm Hg. Art. During the electrical switching on of the SC equipment, an increase in the temperature of the SC and an increase in the calculated pressure in the chamber from 1⋅10 ^-4 mm Hg were observed. Art. up to 3.8⋅10 ^-4 mm Hg. Art. In addition to the vacuum chamber, we connected a high-vacuum cryogenic pump with a high capacity. As a result, the pressure in the vacuum chamber was lowered to the calculated value of 1⋅10 ^-4 mm Hg. and continued electrical checks of the equipment under the program until its completion. The results of the experiment confirm the claimed technical solution.

The proposed technical solution makes it possible to increase the reliability of the test results of the spacecraft when it is tested for performance by improving the simulation and maintaining full-scale operating conditions during ground testing. The proposed method is quite simple to operate and does not require the development of new equipment.

Claims (1)

A method for simulating pressure in a vacuum chamber during ground testing of spacecraft for operability, which consists in placing the spacecraft in a vacuum chamber, evacuating the vacuum chamber to a residual pressure using a vacuum evacuation system, and checking the spacecraft for operability with electrical inclusions of the equipment included in the its composition, characterized in that the value of the pressure of the own outer atmosphere of the spacecraft is calculated depending on the height of the working orbit of the spacecraft, the value of the residual pressure in the vacuum chamber is taken equal to the calculated value of the pressure of the own outer atmosphere of the spacecraft, and with an increase in the pressure of the own outer atmosphere of the spacecraft apparatus in the vacuum chamber in the process of checking the spacecraft for operability maintain its value at a given level by increasing the performance of the vacuum pumping system.