Yury Razoumny
Doctor of Technical Sciences
Professor, Director of Academy of Engineering,

It's not enough to find mathematical description of the phenomenon, to discover its internal regularities and make the formulas beautiful is the aim. 


Diploma in Engineering of St. Petersburg Mozhaisky Military Space Academy, Specialty — Astrodynamics.

1980 - 1983

Engineer, Senior Engineer at Remote Space Mission Control Center, Town of Ussuriysk, Primorsky Region.

1983 - 1996

Junior Scientific Researcher, Senior Scientific Researcher, Head of Scientific Laboratory, Deputy Head and Head of Scientific Department for Space Mission Design at Tichonravov Central Research Institute of Space Means.


PhD Certificate, issued by Supreme Examination Board under Council of Ministers of USSR, Specialty — Dynamics, Ballistics and Spacecraft Motion Control.


Senior Researcher Certificate issued by Supreme Examination Board under Council of Ministers of USSR, Specialty — Dynamics, Ballistics and Spacecraft Motion Control.


Grand PhD Certificate issued by State Supreme Examination Committee of Russian Federation, Specialty — Space Navigation, Means and Methods. Theme — Fundamentals of Theory for Satellite Constellation Design for Discontinuous Earth Coverage.

1998 - present

Academician of Tsiolkovsky Russian Academy of Cosmonautics.

1996 - 1998

Head of Department at State Committee for Military Technical Cooperation of Russian Federation, Head of Department at Ministry for Foreign Economic Affairs of Russian Federation.

1997 - 2001

Professor of department for world economics at Russian State Trade-Economic University, currently Plekhanov Russian University of Economics (author’s course «International Trade of Armament»).

1998 - 2007

Professor of Department for Ballistics and Aerodynamics at Bauman Moscow State Technical University.


Diploma of Professor issued by Ministry of Education and Science of Russian Federation at the instance of Bauman Moscow State Technical University, Specialty — Ballistics and Aerodynamics.

2007 - 2011

Professor and First Deputy Head of Department for Dynamics and Flight Control of Rockets and Spacecraft at Bauman Moscow State Technical University.

2011 - 2012

Head of Centre for Space and Rocket Systems Quality Assurance and Space Mission Design at Central Research Institute for Machine Building.

2012 - 2017

Professor of Department for System Analyses at Moscow Aviation Institute.


Correspondent Member (2006) and Academician (2010) of International Academy of Astronautics (IAA).


Lifetime Associate Fellow (2008) of American Institute of Aeronautics and Astronautics (AIAA).

2014 - present

Co-Editor of Acta Astronautica, Great Britain.

2015 - 2016

Head of Department for Space Flight Mechanics of Institute of Space Technologies at RUDN University.

2016 - present

Professor and Head of Department for Mechanics and Mechatronics, Head of Academy of Engineering at RUDN University.

2013 - present

Member of Astrodynamics International Program Committee of the International Astronautical Federation.

2019 - present

Vice-Chair of Commission 3 for Space Technology and System Development at International Academy of Astronautics.


He reads a series of disciplines to undergraduate and graduate students of the RUDN University:

  • «Space Flight Mechanics»
  • «Satellite Orbit and Constellation Design»


  • Yury N. Razoumny took part in the management of the Russian orbital grouping of automatic and manned spacecraft and in the ballistic justification of promising space technology for various purposes. Yury N. Razoumny developed and implemented new methods of spacecraft control, created the foundations of the theory of optimization of orbits and orbital structures of satellite systems based on the characteristics of the Earth.
  • Yury N. Razoumny developed and implemented a systematic approach to managing the promotion of domestic space and military products to foreign markets within the framework of military-technical cooperation between the Russian Federation and foreign countries.
  • Yury N. Razoumny conducts research in the field of creating key elements of a new generation of space infrastructure: for controlling the movement of spacecraft, optimizing the orbits and orbital structures of satellite systems for various purposes, ensuring the safety of space activities in conditions of space pollution, creating and using satellite systems for remote sensing of the Earth. Yury N. Razoumny heads the international research team of the International Academy of Astronautics to develop a new generation of advanced space infrastructure based on the concept of maintenance of spacecraft in orbit (IAA Study Group 3.22).

Scientific interests

  • System analysis, mechanics and control processes, mathematical methods of optimization of complex technical systems.
  • Mechanics of space flight, methods for controlling the movement of spacecraft, methods for designing orbits and orbital structures of satellite systems, methods for creating and applying satellite systems for remote sensing of the Earth, the problem of space debris and methods for ensuring the safety of space activities under existing risks and restrictions.
  • Management methods in social and economic systems.
The problem of satellite constellation design for Earth coverage using elliptic orbit is considered. Whereas various researchers in this field have mainly considered optimization of the orbital structures of constellations, this paper deals with a previously insufficiently studied problem of optimizing the orbital geometry by coverage characteristics, that is, selecting the form of an elliptic orbit (semimajor axis and eccentricity) to provide the best performance in terms of coverage. From this point of view the class of the so-called locally geostationary orbits is suggested and substantiated. It is shown that optimization in the class of locally geostationary orbits, while the problem of Earth coverage on elliptic orbits is considered, leads to maximum duration of the satellite visibility zones. It is shown that this class of orbits includes the geostationary orbit, the only circular orbit in the class, and known Molniya-type elliptic orbit, as well as an infinite domain of elliptic orbits corresponding to the maximum visibility zone duration among all possible elliptic orbits. The general mathematical relations and optimal solution peculiarities for locally geostationary orbits design are presented.
The way to solve the problem of satellite constellation design was outlined in the 1960s, recognizing the importance of satellite coverage (continuous or periodic) function and allowing interpretation of the operation of different types of space systems. Due to the fact that Earth periodic coverage optimization is extremely complex, for many years, the solutions of this problem have been searched for among a priori fixed constellation types successfully implemented before for continuous coverage, with continuous coverage seeming to be much easier than periodic coverage. In this study, it is shown that the technological advance in satellite constellation design for periodic coverage could be achieved by considering it as a unique and separate problem. The introduction in the route theory for satellite constellation design for Earth periodic coverage that aims at creating methods for optimization of arbitrary constellations, which is an alternative to the traditional approach that considers narrow classes of constellations to be analyzed, is described. The so-called route constellation is presented as a mathematical abstraction for approximation of arbitrary satellite constellation. The theory elements of the optimization procedure in the infinite domain of route constellations are introduced. Previously unknown regularities in Earth periodic coverage and in localization of optimal low-Earth-orbit satellite constellation parameters are presented and illustrated.
The design of constellations with big number of satellites is recently of interest to increase redundancy in communications, to provide updated high-resolution Earth's images, to provide internet from space, to take rapid decisions in emergency situations, and to increase coverage and accuracy in Earth observation. Large companies are now moving from planning to invest several billions of dollars and seriously considering the opportunity to design very large constellations. This paper investigates the problem of designing very large satellite constellations for Earth coverage - the constellations with big number of satellites (hundreds and thousands of satellites) in circular orbits. This is done using the Flower Constellations theory together with the elements of Route Constellations theory to have all satellites on the geosynchronous orbits moving along one or several repeated tracks on the Earth surface. Geosynchronous orbits are orbits whose orbital period is synchronized with the period of a rotating frame. This implies a relationship between the location of the satellites (in term of mean anomalies) and the R.A.A.N. value. The satellite trajectories in the constellation are designed such that they have not self-intersections. This condition, embedded in the theory, provides specific upper bounds for orbit inclination. These bounds can be increased by selecting inclinations maximizing the minimum distance. The examples of Flower Constellation configurations made with 2000, 3000, and 4000 satellites are presented. The configurations are independent from the orbital altitude, which is defined based on other constraints (resolution, communication power, van Allen belts).
Estimates of the maneuvers of active space objects are considered. We propose analytical and numerical-analytical algorithms to estimate short-term and long-term one-impulse maneuvers for the case where the initial and final orbits are determined with errors. Both coplanar and noncoplanar maneuvers are considered. Special attention is given to the velocity and reliability of the solution of the problem. The process to find the solution has a geometrical interpretation. We provide examples of estimates for maneuvers of spacecraft located at geosynchronous orbits. The results obtained by the proposed method are compared with the results obtained by the traditional approach, excluding errors of orbit determination.
The paper overviews the current status of optimization methods which are aimed, or could be partially used, for the solution of the problem of satellite constellation design for continuous near-Earth space global coverage. It reviews current basic terms and definitions as well as introduces new ones relevant to the problem mentioned. The new mathematical approach and methodology of optimization the compound, two-Tier Walker Delta Pattern constellations to provide continuous near-Earth space coverage is presented. The examples of its practical implementation are presented as well. The advantages of two-Tier Walker Delta Patterns, in comparison with classic one-Tier Walker Delta Patterns, are shown for the problem discussed.
This paper opens a series of articles expounding the fundamentals of the route theory for satellite constellation design for Earth discontinuous coverage. In Part 1 of the series the analytical model for Earth coverage by satellites’ swath conforming to the essential of discontinuous coverage, in contrast to continuous coverage, is presented. The analytic relations are consecutively derived for calculation of single- and multi-satellite Earth surface latitude coverage as well as for generating full set of typical satellite visibility zone time streams realized in the repeating latitude coverage pattern for given arbitrary satellite constellation. The analytic relations mentioned are used for developing the method for analysis of discontinuous coverage of fixed arbitrary Earth region for given satellite constellation using both deterministic and stochastic approaches. The method provides analysis of the revisit time for given satellite constellation, as a result of high speed (fractions of a second or seconds) computer calculations in a wide range of possible revisit time variations for different practical purposes with high accuracy which is at least on par with that provided by known numerical simulating methods based on direct modeling of the satellite observation mission, or in a number of cases is even superior to it.
The method for synthesis of satellite orbits and constellations, optimized by given criterion (minimum of required number of satellites in the constellation, or minimum revisit time, or minimum of the satellites' swath width required) for fixed parameters of on-board satellite equipment and constraints for unused criterion parameters of a list of mentioned above is presented. The numerical results demonstrate the possibilities of the method developed basing on analyzing the given satellite constellation revisit time values distributed on the Earth coverage area, and for synthesizing the satellite constellations to minimize revisit time in comparison with the traditional approaches based on constellation design in a priori fixed classes used for continuous coverage. Particularly, it is shown that the suggested synthesis method, basing on the simplest type of Route Constellations considered – Secure Route Constellations, directly leads, as result of high-speed calculations for given Earth region coverage (seconds, or minutes as a worst case), to the optimized satellite constellations which provide consistently high performance and are better, or at least on the same level, in comparison with the best Walker constellations for discontinuous coverage. In order to have comprehensive coverage picture, both deterministic, and stochastic approaches are considered for estimation of the coverage characteristics of the given region of arbitrary shape, basing on the results of Earth coverage analytic emulation.
Continuing the series of papers with description of the fundamentals of the Route Theory for satellite constellation design, the general method for minimization of the satellite swath width required under given constraint on the maximum revisit time (MRT), the main quality characteristic of the satellite constellation discontinuous coverage, is presented. The interrelation between MRT and multiplicity of the periodic coverage – the minimum number of the observation sessions realized for the points of observation region during the satellite tracks’ repetition period – is revealed and described. In particular, it is shown that a change of MRT can occur only at points of coverage multiplicity changing. Basic elements of multifold Earth coverage theory are presented and used for obtaining analytical relations for the minimum swath width providing given multifold coverage. The satellite swath width calculation procedure for the multifold coverage of rotating Earth using the iterations on the sphere of stationary coverage is developed. The numerical results for discontinuous coverage with minimal satellite swath, including comparison with some known particular cases and implementations of the method, are presented.
Basing on the theory results considered in the previous papers of the series for traditional one-tiered constellation formed on the orbits with the same values of altitudes and inclinations for all the satellites of the constellation, the method for constellation design using compound satellite structures on orbits with different altitudes and inclinations and synchronized nodal regression is developed. Compound, multi-tiered, satellite structures (constellations) are based on orbits with different values of altitude and inclination providing nodal regression synchronization. It is shown that using compound satellite constellations for Earth periodic coverage makes it possible to sufficiently improve the Earth coverage, as compared to the traditional constellations based on the orbits with common altitude and inclination for all the satellites of the constellation, and, as a consequence, to get new opportunities for the satellite constellation design for different types of prospective space systems regarding increasing the quality of observations or minimization of the number of the satellites required.
Over the last years many organizations in different countries have been involved in development of various technical aspects of on-orbit satellite servicing, which to a great extent predetermines the characteristics of next-generation space systems. One of the main problems to be considered for developing next-generation space systems basing on on-orbit-servicing concept is developing the special methods for optimization of orbital structure of the servicing space-based system equipped with detached units meant for providing on-orbit-servicing of the given multi-satellite infrastructure, as well as simultaneous optimization of the unit maneuvers parameters during the on-orbit-servicing process. The problem mentioned is considered in the present paper. The method suggested combines the questions of servicing system orbit optimization and detached units maneuvers optimization. The optimization of orbital structure of the servicing system is based on using so-called nodally-synchronized circular and elliptic orbits (without relative nodal regression). This kind of orbits for the satellites of the servicing system provides minimum angular shift between servicing satellite's and arbitrary chosen serviced satellite's nodes, which leads to minimization of the average Delta-V (fuel) for orbital maneuver of the unit detached from the servicing satellite and transferring to its destination - the fixed serviced satellite. The special optimization of the concrete unit maneuver is implemented by the criterion of minimum Delta-V (fuel) with constraint on the maneuver duration. Main features of the method are illustrated by the numerical results presented. Particularly it is shown that the method suggested provides rational design of the servicing space-based system orbits with optimal on-orbit-servicing maneuvers of the detached units.