Dennis Tito, (born Aug. 8, 1940, Queens, N.Y., U.S.), American businessman who became the first private individual to pay for his own trip into space.

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Tito earned a B.S. in astronautics and aeronautics from New York University in 1962 and an M.S. in engineering science from Rensselaer Polytechnic Institute in Troy, N.Y., in 1964. He worked as an aerospace engineer in the National Aeronautics and Space Administration’s (NASA’s) Jet Propulsion Laboratory, where he helped to plan and monitor the Mariner 4 and 9 missions to Mars. In 1972 he moved from astronautics to finance when he helped found the American investment firm Wilshire Associates and created the Dow Jones Wilshire 5000 Composite Index, a measure of U.S. securities markets. He is credited with having innovated the now-established use of mathematical tools, borrowed from his work in astronautics, to determine financial market risks.

Throughout the 1990s Tito negotiated with space agencies in Moscow before securing passage on a 2001 mission to the space station Mir at the cost of $20 million. He began training in 2000 at the Yury Gagarin Cosmonaut Training Centre in Star City, Russia, but the mission was canceled when Russia allowed the Mir station to crash to Earth. Instead, on April 28, 2001, Tito joined two Russian cosmonauts, commander Talgat Musabayev and flight engineer Yury Baturin, on a supply mission, Soyuz TM-32, to the International Space Station (ISS). The move caused some controversy at NASA, which felt that Tito needed several weeks of training at NASA facilities before going to the ISS. Tito stayed six days aboard the ISS before returning aboard Soyuz TM-31. Tito and the Soyuz crew parachuted to Earth on May 6, landing in the steppes of Kazakhstan. Given the arduous training required for his mission, Tito objected to the use of the term space tourist, and since his flight the term spaceflight participant has been more often used to distinguish space travelers from career astronauts. After his historic flight, Tito returned to his position at Wilshire Associates.