The satellite constellation control system is being created at Samara University
The project of nanosatellite control, navigation and communication complex designed for operative feature detection of natural disasters by young Samara University scholars won the grant of Russian Science Foundation. The prototype of the complex which the scientists must test in the space will be the result of the work.
The statistics shows that the number of natural disasters increases every year. The use of the nano-type satellite constellation is able to help solving the problem of ionosphere operative monitoring. The change of its parameters is a serious indicator of the feature detection of the approaching natural disasters.
The precision of measurements and speed of data transfer are required in the sphere of natural disaster forecasts. They can be provided by “controlled” satellite constellations.
However time and navigation reference of scientific measures is necessary for the processing of the monitoring data received from the space. To do it one needs to know the trajectory of nanosatellite movement, time and place when it made the necessary measures as well as at what time and how the sensitive axes of scientific gear were directed in the space.
“99% of modern nanosatellites will not be equipped with navigation sets, the data of NORAD system are used universally. This is the integrated system of the USA and Canada aerospace defense by the means of which every object launched into space is fixed”, - the head of the project, associate professor of Inter-University Department of Space Research at Samara University, Andrey Kramlikh, explained. The specialists of this organization with a certain operative efficiency provide open access of TLE data (files with the elements of satellite orbits which can be put in the model of movement and then determine and forecast the movement of the satellite) depending on the importance of the project. “But the movement model is always different from real movement. And if the precision of TLE data for the organization of communication session is enough, then it will not be possible to tie with it high-precision measurements. That is why it is necessary to install its own navigation set onboard of a spacecraft”, - the young scholar added.
The developers note that a navigation set cannot work permanently at nanosatellite as it consumes too much energy. That is why they suggest measuring aboard of the nanosatellite and process the navigation data on the Earth – it will reduce the running time of the set considerably.
Abroad there are developments similar to the control complex, navigation and communication being developed at Samara University. “They cost a lot, and their durability is not guaranteed, - Andrey Kramlikh made the point. – Our system must be cheaper”.
The young scientist draws attention to the fact that small dimensions, mass and cheap in comparison with the bigger small spacecraft cost of the nanosatellite allows launching into orbit several craft at the same time and measuring in many areas of space simultaneously. It will give the opportunity to get a spatial pattern and to follow its changes in time.
However for monitoring of the ionosphere it is important not only to launch several nanosatellites, but to sustain a certain configuration of their movement and it is possible to reach this only by controlling the movement of the small spacecraft. Moreover, it is necessary to control the orientation of every satellite in the constellation. For this the control system that has already been partially tested by young scholars is necessary. They created damping systems – damping of rotation rate to reduce the satellite rotation after dropping. The next stage is the solution of satellite reorientation question.
The scholars must also develop the operational intercommunication system that will allow transmitting information to the Earth quickly and in large quantities. Traditionally the data transfer from the satellite is being implemented at the moment when the device is flying above the mission control center (MCC). Averagely communication session occurs 4-8 times a day and lasts for 5-10 minutes, but when emergency situations requiring operative efficiency happen that is not enough. To enhance it the group of Samara University scholars plans to use low altitude communication networks, i.e. GlobalStar, Iridium, this will allow organizing another scheme not depending so rigidly on the communication sessions with MCC. In this case urgent data from nanosatellite will be transferred to the communication satellite flying at low altitude which will transfer it to the Earth. With this the main mass of information will be loaded later at MCC.
“We embark on a course of import substitution – only Russian equipment will be used in the complex of control, navigation and communication. Samara University has experience of nanosatellite creation, strong school of satellite radionavigation headed by Professor Igor Belokonov. The school on navigation sets under the guidance of Danish scientist Kai Borre appeared as well, now it is headed by associate professor Ilya Kudryavtsev, consequently, the “hardware” component appeared. Thus we can now create completely our own set, to be precise the predictable pattern”, - the head of the project made the point.
The grant for the complex development is given to the researchers for three years. At the end of this time the group of young scholars must present the prototype of the system of control, navigation and communication, and then to test it on the satellite in space.
The topicality to the nanosatellite complex of control, navigation and communication is given by the fact that it is not narrow focus specialized. The other way around, the system is able to solve multidisciplinary applied tasks. In future it can be required at maneuvering satellites and Earth observation satellites as well as small spacecraft monitoring vessels and oil-and-gas pipelines in hard-to-reach areas. Moreover, due to the complex it will be possible to create a snooper satellite that will be able to monitor the surfaces of big spacecraft and in due time to inform about their breakdowns. Joint information from several satellites equipped with the new system and specialized scientific equipment will help in the questions of national security. Analyzing the data about the changes of the Earth ionosphere specialists will be able to follow what has provoked them, i.e. natural processes that are going on the Sun or in the depth of the Earth or an artificial intrusion of a human being.