by Boris CHETVERUSHKIN, RAS Corresponding Member, head of the Keldysh Institute of Applied Mathematics, Russian Academy of Sciences, Konstantin BRUSHLINSKY, Dr. Sc. (Phys. & Math.), Chief Research Associate of the Keldysh Institute

This is the birth centenary of Mstislav Vsevolodovich Keldysh, an outstanding Soviet scientist who has made a signal contribution in a variety of fields, mathematics and mechanics in particular. In 1961 through 1975 he headed the national Academy of Sciences. Dr. Keldysh was in for many kudos and awards. Thrice Hero of the Soviet Union (1956, 1961, 1971); winner of the Lenin Prize (1957) and two Stalin Prizes (1942, 1946). We find this information in encyclopedias and handbooks. Yet a good deal-perhaps the most important things-are not said or else downplayed there. To us who knew Keldysh very well and who worked under his guidance, he is above all the founder and the first director of our Institute that in 1978 was named for him. We could see and hear this man and feel his impact on the performance of our collective.

Keldysh was a man of extraspecial talents and marvelous capacity for work. A likable man of great charisma, he carried immense authority. He belongs to a cohort of scientists who chartered new trends in science that changed the course of human history. Although he did not live a very long life, he made a giant contribution to science and engineering, to our culture and history. And yet many from among the present generation of college and university students–even those majoring in applied mathematics–know but little about Keldysh. His life and work are covered in a collection brought out by Nauka Publishers (M. V. Keldysh: Creative Portrait). Prepared for the press by the Russian Academy of Sciences jointly with the Institute of Applied Mathematics and the Keldysh museum, this book appeared in 2001 and 2002 in two small prints. It carries articles and reminiscences of his contemporaries, the lead scientists Anatoly and Pavel Alex-androvs, Viktor Ambartsumyan, Lev Artsimovich, Ivan Vinogradov, Alexander Ishlinsky, Mikhail Lavrentyev, Boris Rauschenbach, Leonid Sedov, Andrei Tikhonov and many others. These materials collected by the Keldysh museum over 20 years draw a multidimensional portrait of this brilliant scientist, man and citizen, and reproduce an impressive picture of the "golden age" of national science.

Mstislav Keldysh was born on the tenth of February 1911 in the city of Riga into a family of Russian intellectuals of noble birth, a family of lofty civic virtues. Both of his grandfathers were army generals, one serving in the infantry, the other being a surgeon in the medical corps. His father, Vsevolod Keldysh, was likewise with the military, he was promoted to a rank of major-general in the Soviet years. A topnotch engineer, he was one of the first in this country to use ferroconcrete in the building industry. Besides, he was on the faculty of the Riga University as a lecturer. In 1915 the Keldysh family moved to Moscow. Vsevolod Keldysh, the father of the family, continued his career of a lecturer and then came to head academic chairs in the Academy of the Corps of Engineers transferred to Moscow from Leningrad (St. Petersburg) in 1932. As an experienced civil engineer he was involved in the famous projects of the day, such as the DnieproGES (the Dnieper Hydro-Power Station), the Moskva-Volga Canal and the Moscow underground, the Metro. He also supervised the construction of river bridges in Moscow. For a time he served as Vice-President of the Academy of Architecture of the USSR, reorganized in 1956 into the Academy of Construction and Architecture. The mother of the family, Maria Alexandrovna (née Skvortsova), devoted herself to homemaking. Braving the hard years of revolutionary turmoils of 1917 and Civil War (1918-1922), she reared seven children who, for all the rough and tumble of those days, made their way in life.

One of their sons, Mstislav, was a standout. One of the schoolteachers, Konstantin Vayev, the astronomer who taught mathematics, noticed the boy's bent for the hard sciences-he would "make the grade", the schoolmaster said. Yet the Keldysh boy was all set to follow in his father's footsteps and become a building engineer. As a sixteen-year high school graduate (he left school ahead of time), he could not qualify for admission to a civil engineering college. His older sister, Lyudmila, who was attending the Department of Physics and Mathematics at Moscow University (and who became a notable expert in geological topology and the set theory), talked

the young man into seeking enrollment in Moscow University where he found himself as a budding mathematician praised by eminent scientists.

Upon graduation in 1931 Mstislav Keldysh joined the famous TsAG1, the Central Aerohydrodynamic Institute, on Alexander Nekrasov's recommendation (a noted expert in theoretical mechanics and aerohydro-dynamics, Nekrasov was elected to the national Academy of Sciences in 1946). Mathematics and its applied occupations became his lifelong concern. At TsAGI he teamed up with Sergei Chaplygin and his group. Chaplygin assigned the young graduate to deal with an important task at hand, the destructive flutter and shimmy, or aircraft wing and chassis vibrations. Keldysh was quick in having it out and in what should be done to avoid snakebites. Keldysh joined hands with Lavrentyev, Sedov and Felix Frankl in theoretical multitasking in the field of mathematical aerodynamics.

Side by side with applied works on mechanics, Keldysh was also closely concerned with theoretical problems of mathematics, his old passion of the university days. He combined his work at TsAGI with research at the Steklov Institute of the Academy of Sciences. The results he obtained in the theory of analytical functions, polynomials and in the spectral theory of non-conjugate linear operators were rewarded by academic degrees, M. Sc. (1935) and doctorate (1938). Those were ground-breaking discoveries opening up new avenues in science.

Keldysh left a signal trace in this country's higher education, the world's best according to expert opinion. Science veterans who attended his lectures at Moscow University (e.g. on the theory of complex variables) are pleased to think back to those days. In 1946 Keldysh, a 36-year-old member of the Academy of Sciences wielding a good deal of prestige and authority, took part in setting up a Department of Physics and Technology at Moscow University, a department that grew into the famed Phiztekh, the Moscow Institute of Physics and Engineering where he took charge of the Thermodynamics Chair.

During the Great Patriotic War of 1941-1945 Keldysh as head of the TsAGI's Department of Dynamic Strength was closely involved with the problem of vibration survival capability. He often visited aviation plants. His findings and recommendations helped prevent flutter-related emergencies and crashes.

In 1943 Keldysh was elected to the USSR Academy of Sciences as corresponding member. He continued his hands-on research in the aerospace industry. In 1944 he founded and headed a Department of Mechanics in the Steklov Institute. His seminars gave birth to a new line of research, rocket dynamics and celestial mechanics...

In 1946, Keldysh, then a full member of the Academy of Sciences, got a new job at NII-1 (Research Institute) of the Ministry of the Aviation Industry (Keldysh Research Center today) where he supervised rocket engineering.

Yet another line was born at the Mathematics Institute soon after World War II as the physicist Yuli Khariton* and colleagues from the secret Design Office No. 11 at Sarov asked Acad. Ivan Vinogradov, head of the Steklov Institute, to send them a mathematician for A-bomb calculations. He did not hesitate and recommended Keldysh as one "conversant best of all with any maths applications". In the fall of 1946 a Calculation Office was set up at Sarov, with Keldysh as deputy director in charge of applied problems supervising the activities of this office.

This project was instrumental in creating the nation's missile-nuclear shield in good time. In 1953 the Steklov Institute of Mathematics established an Applied Mathematics Department, actually doubling as a research center in its own right; Keldysh became its organizer and first director. Incorporating the above Calculation Office and two laboratories of the Geophysics Institute of the Academy of Sciences, it pooled efforts on the mathematical modeling of processes in nuclear physics. This job was guided by such lead mathematicians as Mstislav Keldysh, Andrei Tikhonov, Alexander Samarsky and Israel Gelfand together with the physicists Yuli Khariton, Yakov Zeldovich, Igor Tamm, Yevgeny Zababakhin, Andrei Sakharov, David Frank-Kamenetsky, Yuri Trutnev and Yuri Babaev who would come regularly from secret "objects", or the research centers at Sarov and Snezhinsk.

* See: V. Lukyanov, "A 'Nuclear Hermitage' at Sarov". Science in Russia, No. 3. 2009; A. Vodopshin, "On a Visit to Khariton", Science in Russia, No. 5. 2009.–Ed.

Affiliated with these departments were the teams of Dmitry Okhotsimsky, an expert in celestial mechanics, and Anatoly Dorodnitsyn, an eminent mathematician, geophysicist and mechanic. They joined hands on a variety of tasks geared to the nascent space research program. They employed the noisy Mercedes electromechanical calculating machines of German make that resembled, both in look and size, regular typewriters. In 1954 to 1955 this laborious and time-consuming job was delegated to STRELA and BESM-1, the first home-made fast electronic computers in service at the Department of Applied Mathematics and at the Institute of Fine Mechanics and Computation Technology of the Academy of Sciences. These machines were employed for the first time in this country for computations on a large scale like that. The work collective, mostly college and university graduates, had to learn how to handle these computers and master associated software. Simultaneously, they lent a hand in developing numerical methods of computing. This laid a groundwork for present-day computing mathematics and spurred progress in allied fields of the basic sciences, in particular, differential equations and mechanics of continuous media. The Keldysh-led collective was ushering in a new era in the life sciences. The techniques thus evolved facilitated computing and modeling operations and even replaced costly experiments now and then. Today this methodology is known as a mathematical modeling of processes, in physics above all.

Meanwhile Keldysh and his team were pushing ahead with space-related work begun at the Steklov Institute. By October 1957 as this country launched the world's first artificial satellite of the earth, the famous sputnik*, they had obtained essential results on rocket parameters and flight control characteristics. For one, they came forward with the idea of a ballistic descent of a space vehicle from orbit to earth, and devised a system of passive stabilization of orbiters. In the 1950s the Department of Applied Mathematics (elevated to the status of a research institute in 1966) formed a school involved with space flight dynamics, the school that gained international recognition.

In 1957 Keldysh and his men expanded the range of their research activities sizeably. In particular, they worked on finding and correcting the flight path trajectories of orbiters, and pinpointing orbits from optical observation data. Subsequently a Ballistic Center was instituted there that became part and parcel of flight control and monitoring (catering, for one, to the Soviet orbital complex MIR). Simultaneously the moon project** was proceeding apace alongside Mars*** and Venus**** flight programs. The selection of lunar fly-by trajectories and taking pictures of the back side of the moon was a great achievement, too. The Okhotsimsky-initiated studies in robotics and mechanotronics (involved with movable-electrode tubes) were likewise geared to lunar and interplanetary studies. The newly developed walking rangers were meant to tackle an essentially new class of tasks of controlling sophisticated automatic hardware. This area of science and engineering has gained recognition worldwide.

Carried away by a new line of creativity, young specialists picked up quickly to become big scientists. The Institute's structure changed accordingly. New laboratories sprung up to handle kinetic equations and related problems oriented to transfer processes in nuclear reactors, neutron physics and atmospheric optics as well as problems of computing astrophysics and geophysics. Some of the research staff moved to the Computing Center of the national Academy of Sciences, the Institute of Space Research and to Novosibirsk, the seat of the Siberian Branch of the USSR Academy of Sciences*****. This way the Keldysh Institute's traditions spread far and wide.

Although not personally concerned with plasma physics, Keldysh watched developments in this sphere holding good prospects for space studies. That is why he

* See: G. Grechko, "Satellite Going Into Orbit", Science in Russia, No. 5, 2007.–Ed.

** See: Yu. Avsyuk, "Focus on Lunar Studies", Science in Russia, No. 6, 20О6.–Ed.

*** See: L. Zelyony, K. Pichkhadze, "From Magnetosphere of the Earth to Martian Satellite", Science in Russia, No. 5, 2005.–Ed.

**** See: E. Galimov, "Prospects of Planetary Studies", Science in Russia, No. 6, 2004.–Ed.

***** See: N. Dobretsov, "First Regional Branch", Science in Russia, No. 4, 2007.–Ed.

and his Institute attached much significance to mathematical support of works in controlled thermonuclear fusion launched in the late 1950s by Acad. Igor Kurchatov* and Mikhail Leontovich. For instance, our computations contributed to the creation of a powerful multipurpose plasma accelerator and of low-thrust stationary engines that came into use in 1971 for correcting the orbits of Soviet satellites.

Keldysh came to play an ever greater part in outer space research. He supervised research and expert examination councils, and was one of the organizers of the Soviet space program when the first Soviet sputniks were put in orbit and the first space flight with man on board took place.** In 1961 he became head of the Academy of Sciences of the USSR. What with the rowing role of science in society and in the national economy, Keldysh had to be involved in politics as deputy to the national legislature, the Supreme Soviet, and member of the CPSU Central Committee.

Throughout the 20th century a new characteristic feature of advanced civilization came to light: progress is due not so much to lone wolves, the solitary great minds, as to big creative collectives capable of showing their best if led by highly motivated and can-do chiefs. Only a few are able to measure up. They should combine a wide background, singleness of purpose and respect. Only then will it be possible to channel work toward a desired target. Keldysh belonged to this cohort of the makers of our civilization blazing its trail by their dedicated work.

Following cardiovascular surgery Keldysh at his urgent request was relieved of his duties of President of the Academy of Sciences of the USSR. This happened in 1975. Still he carried on to the end of his days as member of the Academy's presiding body, chairman of the Committee on Lenin and State Prizes and as director of the Institute of Applied Mathematics.

The Soviet state and scientific public gave great credit to the services of Acad. Keldysh. He was in for every kind of awards and honors at home and abroad. He was elected foreign member of sixteen academies and doctor emeritus of six universities abroad. His monuments were put up in Moscow and Riga, and memorial plaques are dedicated to him on buildings where he lived and worked. His name is given to research institutes and other places. A square in Moscow, a research ship, and one of the minor planets of the solar system are named for him. The Russian Academy of Sciences has instituted a Keldysh Gold Medal for outstanding works in applied mathematics and mechanics, and for theoretical works on the exploration of outer space. We are hoping that the name and work of Mstislav Keldysh will live on to inspire new generations of men and women choosing science as their lifetime vocation.

* See: Ye. Velikhov, "He Dreamt of a Sun on Earth", Science in Russia, No. 1, 2003.–Ed.

** See: Yu. Markov, "Step out Into Open Space", Science in Russia, No. 2, 2005.–Ed.