The Soviet Union seemed predominant in the early years of the space race. Mr. Chertok’s systems guided the rocket that bore Sputnik 1, the first artificial satellite to orbit Earth, into space on Oct. 4, 1957; and, on April 12, 1961, the rocket that took the first man into space, Yuri Gagarin. (Less than a month later, Alan B. Shepard Jr. became the first American in space.)
The Soviets embellished their earlier feats. In August 1962, they launched two manned space capsules that would orbit at the same time. On June 16, 1963, they sent the first woman into space, Valentina Tereshkova. In October 1964, three cosmonauts orbited Earth; it was the first space mission with a multiperson crew, five months before a two-man American flight.
By 1969, however, the United States stepped up to the challenge issued by President John F. Kennedy on May 25, 1961, to send an American to the moon by the end of the decade.
When Neil Armstrong stepped onto the lunar surface on July 20, 1969, an unmanned robot probe that Mr. Chertok and his colleagues had launched a week earlier was stuck in orbit around the moon, stalled by a technical problem. It later crashed into the surface.
In his memoir, Mr. Chertok called the American moon landing a “personal defeat” for his country.
Boris Yevseyevich Chertok was born in Lodz, now part of Poland, on March 1, 1912, the son of an accountant. The family later moved to Moscow. Information about his survivors was not available.
Mr. Chertok was an electrician at 17, and by 1930 was working in an aircraft factory. He graduated from the Moscow Energy Institute in 1940. After World War II, he was a member of a team of experts sent to Germany to mine records of the German rocketry program. Another member of that team was Mr. Korolev. They brought back the blueprints of the German V-2, which became the basis for the Soviet missile and space programs.
Mr. Chertok longed to go into space.
In 2001, a Soyuz-U booster blasted two Russian astronauts and an American millionaire, Dennis A. Tito, into orbit for a rendezvous with the International Space Station. Mr. Tito paid $20 million for the trip.
Interviewed at Russia’s mission control center at the time, Mr. Chertok said, “I am a little bit under 90, and if someone presented me with $20 million I would gladly spend it on a ticket to space.”