The Great Future of Small-Sized Satellites

The development of unmanned space exploration is striving for miniaturization. Modern technologies make it possible to create lightweight small-sized devices - quickly, cheaply and in large quantities. In solving certain tasks related to outer space research, such nano- and microsatellites are not inferior to larger devices. They are also used for testing new technical approaches.

The universal format of such satellites is a cubesat, a 10 × 10 × 10 cm cube, the so-called one unit. From such cubes, one can create larger devices, depending on the tasks set. The single standard and low cost of designing and launching them allow widely using cubesats, including multi-unit ones, in education and university science.

So, in November 2024, Samara National Research University launched another nanosatellite "SamSat-Ionosphere". The device allows obtaining data on the state of the Earth’s ionosphere and magnetosphere, which can be used to predict communication outages and improve the accuracy of navigation systems.

Purchased systems can disrupt the mission

All systems on the satellite, or the vast majority of them, must be of our own design. Otherwise, according to Igor Belokonov, Head of Samara University’s Interuniversity Department of Space Research, it is impossible to guarantee the operability of the device and the success of the mission. Therefore, since 2016, the University has been designing and creating nanosatellites completely independently, without buying any onboard systems.

"We have established a complete closed production cycle. Of course, this situation has been caused not by good life and has objective reasons", notes Igor Belokonov. "The fact is that the conditions, in which space experiments are conducted, are so versatile that it is impossible to be sure that everything is guaranteed to go as planned. A satellite is an electronic device with a huge number of various onboard systems: controlling, power supply, radio communications, computation… If we install somebody else’s systems, then in the event of an emergency, we‘ll be limited in our understanding of what is happening, because we do not know specific features of the onboard systems. And none of the sellers will tell you about the full functionality of the product and all its options. Therefore, we make our product of the universal element base, and the young specialists of our laboratory know absolutely everything happening inside the device".

For example, young scientists from Samara University have designed their own dual-frequency navigation receiver. It is considered not only as a device for solving typical tasks such as detecting coordinates and velocity, but also as a scientific device. The radio signal that travels from the satellite to the receiving antenna varies depending on the properties of the medium, through which it propagates. Accordingly, it is possible to solve the opposite problem: to evaluate changes in this environment.

Another development by Samara University is the electrothermal engine. The alcohol-water mixture, actually vodka, is heated in the installation, and the superheated steam is ejected from the nozzle, creating the reactive force, which K.E. Tsiolkovsky wrote about many years ago. In ground tests, the engine showed high specific impulse specifications, twice as high as that of its French analog device. In future, such engines will be installed on nanosatellites for orbit correction. So far, Samara University’s devices are sent without engines. Another theoretical application is the development of the cosmonaut rescue system based on the electrothermal engine during extravehicular activities. "When going into outer space, cosmonauts use two snap hooks to be buckled in turn when moving outside the space station. If the snap hooks are unfastened and the cosmonaut loses contact with the station, (s)he will actually become a satellite of the Earth. For returning, (s)he needs to get hooked to something. We have patented the robotic system for rescuing cosmonauts in such a situation, based on the use of our engine: it can be a three-unit satellite, which, in case of an emergency, separates from the station in the direction of the cosmonaut and pulls a cable behind itself", explained I.V. Belokonov.

University research of the ionosphere

In June 2023, the satellite "SamSat-ION" created on Samara University’s unique platform was launched into a circular orbit with its height of 550 km. On November 5, 2024, "SamSat-Ionosphere", the improved version of the first spacecraft, equipped with the updated software and the improved power-supply system, went into space. "SamSat-Ionosphere" examines the parameters of the upper ionosphere and the state of the Earth’s magnetic field. This is a 10 × 10 × 30 cm three-unit cubesat. Both "SamSat-ION" and "SamSat-Ionosphere" are fully developed and created by young scientists and postgraduates from Samara University.

"Our department implements the full production cycle of such satellites: from designing the boards to assembling and writing software for the satellite and the ground receiving station. In the classical architecture of such satellites, individual cubesats are obvious to distinguish. When using this architecture, boards connecting multiple units are required. Our platform differs by using the single-stack architecture: the entire device is a single unit that does not need additional connections. Besides, our platform provides a number of improvements to ensure a stable communication channel, and the antenna system with the patented element deployment system is used, which is different from analogues", said Stepan Shafran, Researcher at the R&D Laboratory for Advanced Fundamental and Applied Space Research based on Samara University’s nanosatellites. Usually, before opening, the antenna of a nanosatellite is located in a special compartment, coiled into a spiral. The flap keeps it from unfolding. In a conventional system, this flap is attached to a nylon thread, which is burned out after a signal is given to open the antenna. However, the nylon thread can wear out during the launch, and for burning it out, you need increased resistor temperatures. The locking mechanism for opening the antennas uses the Rose’s alloy of tin, lead and bismuth, which melts at the temperature of 94 °C and is more resistant to vibrations.

In 2025, it is planned to launch the next nanosatellite "SamSat-Orion" furnished with scientific equipment for radio illumination of the ionosphere, created at the Space Research Institute of the Russian Academy of Sciences.

In future, Samara scientists’ research satellites will form a grouping for research in the interests of Roshydromet. Resources of Samara University’s Laboratory are estimated to be enough to create up to ten such satellites annually.

Samara "AIST"

Another satellite project by Samara University is related to radar monitoring of the Earth’s surface. Launching the device "AIST-ST" was supposed to take place at the end of December 2024, but it was postponed to 2025. There are fewer direct developments by Samara University in this 16-unit satellite, but most of its components, including solar panels, batteries and electronics of the onboard computers, are made in Russia.

The satellite’s radar operating in the X-band (from 8 to 12 GHz) will make it possible to take images of the Earth’s surface both at night and in cloudy weather: clouds are transparent for this frequency range. The device can be used, for example, for assessing the movement of icebergs, melting glaciers, studying the surface relief and searching for polluted areas of the seas and oceans. "We conducted test surveys using this radar in ground conditions and got a good image: we can see radio shadows from trees and infrastructure facilities. Herewith, two modes of operation will be possible: route mode, which covers a large area, but gives a lower-quality image of about 10 m per pixel, and detailed mode, respectively, with an increased quality of about 2 m per pixel, but with a smaller image area", said Maksim Ivanushkin, Head of the Cyber-Physical Factory of Small-Sized Spacecrafts.

As an additional payload, "AIST-ST" will have a sensor for assessing the contamination of the spacecraft’s surface, which will allow assessing the satellite’s own external atmosphere. This is a development by Samara National Research University’s Institute of Space Instrumentation Engineering .

"AIST-ST" will become the first Russian small-sized cubesat satellite with radar equipment onboard. After assessing outcomes of its operation, the grouping of similar devices is probable to be created.

Source: scientificrussia.ru