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Okhotsimsky Dmitrii Evgenievich
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#REDIRECT Dmitrii Evgenievich Okhotsimsky
Dmitrii Evgenievich Okhotsimsky , an outstanding Soviet/Russian space scientist, pioneer of space ballistics in the USSR, author of fundamental works in applied celestial mechanics, control in space and robotics.
Biography
Okhotsimsky was born and lived his whole life in Moscow. His father Evgenii Pavlovich Okhotsimsky was an accountant/auditor, his mother a housewife. Okhotsimsky was very attached to his parents and always lived together with them. At the age of 15 he suffered dyphteria in a hard form and was prohibited from any sports or physical activity. Nevertheless he showed his whole life remarkable energy and good health, and was actively working until his death at the age of 84. He entered the Department of Mechanics and Mathematics of the University of Moscow in 1939. When the war broke, the department was temporarily closed. He participated in the building of defense installations around Moscow, worked at the munitions factory. In 1941 he was conscripted to the Red Army but was dismissed in 1942 for vision problems (severe nearsightedness, he would be almost blind without strong eyeglasses) and returned to the University. In 1946 he presented a paper about the optimization of the missile flight, where he was able to find an analytical solution using an original technique of variational analysis, a precursor in some respects to what was later formulated in a more general form as the Pontryagin maximum principle (Lev Pontryagin). In 1949 he joined the Mathematical Institute of the Russian Academy of Science, where was working in the department of Applied Mathematics lead by Mstislav Keldysh, the future President of the Russian Academy of Sciences. Keldysh was an active member of the think tank behind the space program and his support was instrumental for active integration of Okhotsimsky and his group in space projects. Later the department of Keldysh became a separate institute currently known as the and the group of Okhotsimsky became a department in this institute, which he was leading until his death.
Space ballistics
Since his first student work, Okhotsimsky was interested in analytical and numerical solution of variational problems to which the optimization of space mission can be reduced: how the mission can achieve its target with the mimimal total fuel consumption (possibly combined with other criteria and restrictions). Using first Soviet computers (such as Strela computer, an analog of a famous Eniac) he worked with his colleages to develop new generation of numerical methods and principles of programming. After the launch of the first satellite he published a few papers were the mathematical aspects of the launch and evolution of the orbit were analyzed. Okhotsimsky’s leadership was instrumental in the development within his department of the remarkable group of young talents collectively nicknamed “Keldysh boys”. Many of them became well-known, such as E.L. Akim, T.M. Eneev, A. K. Platonov, V.A Egorov, V. A Sarychev, M. L. Lidov, V.V Beletsky. Okhotsimsky contributed to the planning of multiple space missions including launches to Moon, Mars and Venus. His analysis of the first failed docking attempts on “Soyuz” spacecraft helped to quickly find a reason of mechanical instability and develop successful docking techniques. Together with E.F. Golubev and Yu.G. Sikharulidze he developed a concept of a dual-entry aerodynamically controlled landing algorithm of a spacecraft where the two-stage entry was used to reduce speed and achieve an accuracy of landing of a few km. He developed the methods on the passive stabilization of satellites using the gravity gradient and the non-sphericity of the tensor of inertia.
Robotics
In the middle of the 1970’s Okhotsimsky became interested in robitics, especially in the modeling and control of insect-like walking. A few successful models of 6-legged walking robots were created including systems with autonomous vision able to climb the stairs and handle complicated terrain. In the work of Okhotsimsky and his school realistic mechanical modeling of the motion was typically combined with sophisticated algorithms adapted to the context of a particular task. He usually advocated a “from the bottom up” approach aimed at first handling particular low-level problems and then moving to assembling a more general setup. He thought that this is the way the nature works in the making of live creatures. He organized first robot competitions in Russia called festivals "Mobile robots", which was named in 2003 after his close colleague professor Devianin.
Other work
Aside from his main field of interests, he also made remarkable contributions in gas/liquid dynamics. He determined resonance frequency of liquids partly filling cylindrical tanks, which had direct impact on the stability of launchers [ Okhotsimsky D.E. To the theory of the motion of bodies with cavities partly filled with fluids. Prikladnaia matematika i mekhanika, v. 20, 1, 1956, p. 3-20][. Another well known result was first numerical modelling of the spherical explosion wave in a real gas][Okhotsimsky D.E., Kondrashova I.L., Vlasova Z.P., Kazakova R.K. Numerical modeling of point explosion taking into account counterpressure. Works of the Steklov mathematical Institite, v.1][. Alltogether he authored about 200 papers and 3 books. ]
Positions and social activity
Okhotsimsky combined the talents of a scientist and an administrator. His career was closely linked to the section of Mechanics and Control of the Soviet/Russian Academy of Science, of which he was a deputy-secretary. He was also a president of the specialized council "Robotics".Parallel to his main work in the Keldysh Institute of Applied Mathematics, he was appointed in 1965 a chair of Theoretical Mechanics at the Department of Mathematics and Mechanics at the Moscow State University and performed both functions until his last days. He was always striving to find practical forms of cooperation between the Academy of Science and the University. Until his last days he remained a staunch supporter of the leading role of the Academy of Science as a center of fundamental research in Russia.
Awards and honors
* Member of the Russian Academy of Sciences since 1996 (full list of members: )
* Foreign Member of the Serbian Academy of Sciences and Arts (1998)
* USSR State Prize
* Lenin Prize of 1975 (for his contribution to the lunar mission "Luna-16")
* Hero of socialist labour in 1961, 2 Orders of Lenin and many other orders and medals
* Minor planet 8062 discovered by astronomer Nikolai Stepanovich Chernykh on March 13 1997 was called Okhotsymskij in his honor.
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