SOVAPresenter: The owl is a bird of prey belonging to the Strigiformes order. Thanks to their anatomy the owls are the only birds capable of turning their heads around through 180 and even 270 degrees without turning their body. At the same time the eyes of the owl are immobile and only look straight ahead. This ability, along with binocular vision, enables the owl to notice even the smallest details of their surroundings, which makes it a very efficient predator.

Onboard the International Space Station there is now its own “owl” in orbit – the Russian acronym SOVA, which means ‘owl’ in Russian stands for the system for attitude control of video spectral equipment. The SOVA onboard the ISS, just as a real owl, is on the prowl, but its prey is not rabbits or small rodents, it aims at natural and man-made disasters. All of this is a part of Uragan experiment consisting in trials of the combined terrestrial and spatial system for monitoring and prediction of natural and man-made disasters.
O.I. Skripochka, Hero of Russia: I'm now in the Service Module of the ISS Russian Segment near porthole number Nine, where this equipment is installed. In outward appearance, it is a metal case secured to the porthole. Inside it, there are two mirrors: one movable mirror, which can be rotated using electric actuators, the other is fixed. This optical system is used for pointing the camera or the spectral hardware towards the scene.
Presenter: For example, in the course of the experiment, the SOVA equipment was used to acquire numerous images and spectra in close proximity to an erupting volcano, which was ejecting volcanic ash preventing airplanes from getting closer. In automatic mode, the camera pointing system assisted by data from navigation systems enables cosmonauts and scientists to track on the planetary surface all the phenomena of interest and gain detailed knowledge of these processes. Also, spectrometric measurements are used for solving the problem of object state analysis based on reflectance characteristics, expressed in terms of spectral signatures. Using these data, one could make lithologic, geobotanic, evaluation maps and other kinds of maps. Scientists can learn about the quality of the soil, identify organic compounds contained in water, and even make predictions of crop yields, productivity of fish farms and many other things. Early large-scale experiments in orbital imaging of Earth surface, as well as photography of space objects for scientific purposes, had been conducted even from the first-generation space stations. Salyut-4 station was equipped with lenses built into the module structure itself, and, in order to re-point this multi-ton photographic camera in space, one had to correct the spatial attitude of the entire orbital complex.
M.Y. Belyaev, professor, research supervisor of space experiments: It has to be said that the problem of attitude control in space is not simple. It was at our company that it was solved by a team headed by academician Boris Viktorovich Raushenbakh. This problem was solved in the following manner: the attitude required for performing maneuvers, de-orbiting, and so on, was established by using attitude control sensors and actuating thrusters, and then, if need be, by turning the whole spacecraft around. But, of course, it was not sufficient for conducting experiments, and with the launch of Salyut station, one had to develop an entire procedure for pointing scientific equipment at the objects under study. The problem consisted in limited propellant supply onboard Salyut stations, while attitude control maneuvers required a lot of propellant. For example, it took one or two kilograms to turn Salyut about the long axis X, and more than twenty kilograms about the transverse axis. This problem was solved during conduct of experiments onboard Salyut stations.
Presenter: The problem of controlling the station attitude without spending precious propellant was solved as early as orbital complex Mir. The were gyro force stabilizers, gyrodynes, installed onboard the Kvant module. From then on, the station spatial attitude was controlled with their assistance.
M.Y. Belyaev, professor, research supervisor of space experiments: The Mir station design was very complex. To control Mir, one had to develop a complex package of math models, and it actually continuously worked for fourteen years, and it was only owing to it that the station mission successfully continued and a lot of experiments in pointing science hardware at the objects under study have been completed. Those were, primarily, experiments involving the X-ray equipment package that had just been installed in the Kvant module. Our scientists got lucky at that time, back then in 1986 a supernova exploded in the Large Magellanic Cloud, and this does not happen often: only once in about five hundred years. Which means that plenty of outstanding results were obtained specifically owing mostly to gyrodynes and the math models package, which made it possible to turn the station around and point it at the target. But that wasn’t easy and even back then a steerable platform was installed on Mir, it was attached to the station hull, scientific equipment was mounted onto it, and this platform could be pointed at the target in automatic mode. That platform was called ASPG-M.
Presenter: With the launch of the International Space Station came a rather unpleasant surprise for the scientists and engineers. The ISS mass exceeds 400 tons, and it is bigger than a football field. Gyrodynes turned out to be ineffective for controlling a structure that is so massive.
M.Y. Belyaev, professor, research supervisor of space experiments: Developers of the gyrodyne-based control systems, the US side, did not account for this, although we did contact them, I told them about this, but they didn’t care about this, because at the time the moist important task for them was conduct medical experiments and experiments in microgravity. That is, in their view, the international station was supposed to fly in orbital or quasi-orbital attitude and there was no need to turn it around. But our scientists weren’t happy with that, because on our side all the previous orbital stations of the Salyut series and Mir had been designed for multi-purpose use, and we conducted research in various fields: Astronomy, geophysics, Earth science. And, of course, we had to solve the problem of pointing the hardware at the object under examination. At the start of the ISS mission we used hand-held devices which had to be pointed at their targets by the crew. Then somebody had an idea of building automatic systems, which were named SOVA. We built the first such system very quickly and the last year we sent it to the ISS and it operates perfectly. Mounted on it are a photographic camera, spectrometry hardware, and we acquire excellent images.
Presenter: At present, Rocket and Space Corporation Energia, which is a part of State Corporation Roscosmos, conducts ground tests on additional upgraded systems for that equipment, that will enable a more wide-ranging research.
I.V.Rasskazov, curator of the SOVA scientific equipment: The development process for science equipment goes through a series of phases, one of which consists in building a prototype for design development tests. It is needed to verify engineering solutions adopted for the development of this hardware and test it in the environments it will encounter during transportation and in-orbit use. Currently, we are running climatic tests on our hardware: we need to see whether it can withstand temperature, humidity and other conditions during launch to the ISS.
Presenter: The SOVA pointing system for video spectral equipment is designed to be mounted on the portholes of Service Module and Multi-purpose Laboratory Module of the ISS Russian Segment. This ring will be attached to the porthole, and the imaging hardware will be attached directly onto it, and from that moment on it won’t require any crew involvement to image Earth surface in fully independent automatic mode using coordinates of interest to the scientists taking into account the station position. Data from the cameras are immediately fed to control computer and from there to the scientists.
I.V.Rasskazov, curator of the SOVA scientific equipment: The scientific equipment is a part of the Service Module of the International Space Station, the software that runs that equipment takes all the station trajectory and navigation data directly from the station, and based on coordinates of the targets calculates the required tilt angles of the pointing platform and the optic axis, and tilts the platform.
Presenter: The pointing platform SOVA -228 is installed on the 228 mm porthole of the Service Module and provides the capability of rotating the imaging equipment mounted on it through 180 degrees about the axis of the line of sight and pointing with no less than 20 degrees angle of deflection in one plane from the optical axis of the porthole. Platform 426 will be installed on the 426 mm porthole in both Service Module Zvezda and Multi-purpose Laboratory Module Nauka and will provide the capability of turning the imaging equipment about two mutually perpendicular axes with deflection angles of no less than 30 degrees.
M.Y. Belyaev, professor, research supervisor of space experiments: Of course, the current SOVA works perfectly well for both spectrometry hardware and for Earth surface imaging, but with small lenses. As for equipment with large lenses, I think that after some time in zero gravity the resolution may deteriorate, which would make worthwhile the use of special actuators in these new platforms.
Presenter: The orbital station is the platform with the required environments, where space technologies are being developed. Such a platform make it possible to introduce prompt changes into designs that are being developed. Eventually, a similar technology for pointing video and spectral equipment, after having been developed onboard the ISS, may find its way into unmanned Earth remote sensing satellites. This space ‘owl’, SOVA, will make it possible to change the sight axis without changing the attitude of the spacecraft itself, which, in its turn, will save propellant required for keeping the spacecraft in its orbit, and, thus, will increase the spacecraft life in orbit.

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