Russian scientists have proposed a qualitatively new type of engine for working in outer space. It is based on the principle of plasma excitation using a microwave spark discharge. This unit can be installed on small-format satellites. Unlike the gas-fueled satellite engines that are common today, the new device will use special metal-dielectric plates as an energy source, the reserve of which will be enough for 10 years of autonomous operation. A plate with a radius of 10 cm can replace 1.5 thousand cubic meters of gas fuel. In the future, new engines can be used for the development of the Solar system.
Russian scientists have proposed a qualitatively new type of engine for working in outer space. It is based on the principle of plasma excitation using a microwave spark discharge. This unit can be installed on small-format satellites. Unlike the gas-fueled satellite engines that are common today, the new device will use special metal-dielectric plates as an energy source, the reserve of which will be enough for 10 years of autonomous operation. A plate with a radius of 10 cm can replace 1.5 thousand cubic meters of gas fuel. In the future, new engines can be used for the development of the Solar system.
Small, but perfectly formed
Scientists of the A. M. Prokhorov Institute of General Physics of the Russian Academy of Sciences are ready to create a prototype of a new type of engine for operation in outer space. According to their idea, the movement should occur due to the use of a new type of discharge described by them, which occurs in a gas environment as a result of the action of microwave radiation. Physicists called it the microwave spark discharge (MIR).
— The proposed engine has a number of advantages. The main one is that a metal-dielectric disk is used as a solid fuel in the system — " said Igor Kossy, Head of the Laboratory of gas-kinetic phenomena in the microwave discharge of the IOF RAS.
With the help of MIR, it is possible to act on the metal-dielectric material in such a way as to excite the plasma, which will move the aircraft forward. The power of such an engine will be relatively small, but sufficient for movement in a vacuum. Therefore, the developers propose to start using it on light small-scale near-Earth satellites, which are now in demand in Russia and in the world.
The source of electromagnetic radiation in the new engine can serve as a standard magnetron used in conventional microwave ovens. Dimensions of the equipment — 50x50x100 cm, weight-2 kg. The cost of the new unit is about €1 thousand.
As fuel, the engine needs a metal-dielectric plate. For example, a disk made of plexiglass with a diameter of 10 cm and a thickness of 2 cm can serve as a source of 1.5 thousand cubic meters of gas, which is necessary for generating plasma. Solid fuel will significantly reduce the size of the satellite due to the part of it in which the gas used today for the movement of spacecraft in cylinders is stored. According to the calculations of IOF RAS specialists, the fuel dielectric reserve on board the ICA can be enough for 10 years of autonomous operation.
The complexity of the implementation of the proposed engine and its analogues is relatively weak traction. The power of the mechanical pulse that the satellite acquires as a result of the operation of the device is small. But the authors of the development have an idea how to strengthen this characteristic. The current calculations of the mechanical pulse were made based on the design of the engine, in which microwave radiation is applied directly to the metal-dielectric surface. If, however, the microwaves arrive at the plasma-generating surface, passing through the radio-transparent thickness of the dielectric disk, in theory this can significantly increase the mechanical impulse. But the hypothesis has yet to be confirmed during the experiment.
To wait for the tests
Experts in the field of space technology interviewed by Izvestia reacted to the proposed technical solution of the IOF RAS with cautious optimism. From their point of view, the idea of a plasma engine is interesting, but for the final assessment you need to wait for its implementation "in iron".
"The concept of the engine proposed by Russian scientists has an important advantage: the working fluid in it is initially in a solid, not a liquefied state," said Alexey Baigashev, head of the Astronomical Community at the Immanuel Kant BFU.
According to the expert, all other requirements being equal to the engine, this will significantly reduce the volume occupied by fuel, simplify storage, transportation and preparation of the spacecraft for launch. The key issue is testing the claimed concept in a real spacecraft. Probably, after the development of the new engine and its ground tests, the researchers will launch a test microsatellite, which, with a low mass and cost of launching into orbit, will allow to fully study the operation of the propulsion system in real conditions.
— For the implementation of an ion engine with such a plasma source, a constructive solution and testing in experiments are required,-said Oleg Tsybin, Professor of the Higher Engineering and Physical School of Peter the Great St. Petersburg Polytechnic University (the university is a participant in the project to increase the competitiveness of education "5-100").
We need practical solutions to the problems of materials and technology of a solid surface, its resistance, destruction, thermodynamics, the type and acceleration of ions, their neutralization, the expert explained. After solving them, the advantages and disadvantages of the engine, its capabilities will be more clear.
Adjust the trajectory
It is possible that MIR engines will be useful in a situation where you need to save chemical fuel and adjust the ballistic trajectory for a long flight time, says Alexander Efremov, director of the Educational and Scientific Institute of Gravity and Cosmology of the RUDN.
"However, we do not yet have data on their parameters and capabilities," he pointed out.
The advantage of a potential installation based on a microwave spark discharge, if it is operational — is an accelerated flight to various celestial bodies without the consumption of the working fluid, or with minimal consumption. However, such a technical solution still raises questions, since it has never been practically implemented, said Denis Malygin, Candidate of Technical Sciences, Chief Designer of the Astronomicon laboratory and an employee of the Photonics Department of SPbGETU "LETI". Experimental data do not unambiguously confirm or refute the operability of such an installation, this is due, among other things, to the small value of the expected effect, comparable to measurement errors, the expert noted.
Such ion thrusters are only applicable in the vacuum of space and cannot move vehicles through the atmosphere, says Denis Malygin, because ion thrusters do not work in the presence of ions outside the engine. Such devices have a high energy consumption (1-7 kW), and on small satellites, energy is very limited. Moreover, to achieve acceleration, a new type of engine requires long-term operation, which again returns to the question of the energy of the satellite, he added.
"That's an interesting idea. It can be used in maneuvering engines that are used in the orientation and stabilization system of spacecraft — "said Anastasia Khramtsova, Head of the Aerospace Systems department of the FEFU Project Activity Center.
For main engines, the declared thrust is very small, she believes. The question is how much energy is needed for the installation to work — this is a crucial indicator when choosing an engine for a satellite.
