The Soviet Union led humanity into the heavens, sending the first satellite, man and woman into space, and all were duly celebrated by their country. The cosmonaut Yuri Gagarin, the first person to orbit the Earth, on April 12, 1961, received his nation’s highest award, Hero of the Soviet Union.

Two decades later, the cosmonaut Aleksandr A. Serebrov, who died on Nov. 12 at 69, earned the same honor. But by the time his country’s mighty rocket boosters had lifted him into space four times in the 1980s and ’90s, the heroics of its space program were mostly memory. Mr. Serebrov received little of the acclaim lavished on Colonel Gagarin.

Indeed, as the country’s economy sank — ultimately triggering the demise of Communist rule in 1991 — the space program could only stagger on, its budget severely cut. To help keep itself going, the program resorted to selling rides to Russia’s Mir space station, the only permanent space outpost at the time, finding customers among scientists and space programs in other nations.

And it offered novel space for advertising. An Italian insurance company placed an ad on the side of a booster rocket, while the manufacturer of New Dawn perfume bought space on a launching pad. Cosmonauts floating in space appeared in television commercials. Tourists with deep pockets were invited to visit what had long been ultrasecret space installations.