Oleg Ivanovsky, a Soviet rocket scientist who played a central role in developing satellites at the dawn of the Space Age, including the first vehicle to carry a human being in orbit around the Earth, died Sept. 18. He was 92.
His death was announced by Roscosmos, the Russian space agency.
The cause and location were not reported.
Ivanovsky worked for many years as a top engineer at the secret Soviet space facility known as Star City, where he helped design Sputnik, which was launched on Oct. 4, 1957. The unmanned satellite, only 23 inches in diameter, circled the globe for three months and prompted alarm in the United States that the Soviets had taken the lead in engineering, rocketry and the Cold War in general.
A month after the first Sputnik launch, the Soviets sent Sputnik 2 into space, this time with a dog on board. The dog, named Laika, died after a few hours in orbit, apparently from heat exhaustion, "but she gave much to biology," Ivanovsky later said.
"We didn't know if an animal could survive for longer than a few minutes in weightlessness," he said. "But from the data from Sputnik 2, we could see that she moved, and even ate, after the launch."
Encouraged that a mammal could survive in space, at least for a short time, Ivanovsky took a leading role in building a capsule that could carry a Soviet cosmonaut into orbit. A 27-year-old pilot, Yuri Gagarin, was chosen to fly the spacecraft, called Vostok 1.
In 1960, an explosion at the Soviet launchpad in Kazakhstan killed 126 people, and there were other technical setbacks along the way.
Ivanovsky and other engineers estimated the chances of a successful manned flight at no more than 50-50.
Gagarin wrote a farewell letter to his wife, in case he would not return from his mission, but he blithely sang a folk song as he climbed into the cockpit on April 12, 1961. His heart rate stayed at a steady 64 beats per minute while awaiting liftoff.
Ivanovsky accompanied Gagarin to the cockpit.
"There were all kinds of wild fears that a man could lose his mind in zero gravity, lose his ability to make rational decisions," Ivanovsky told The Associated Press in 2011.
Concerned that an agitated or deranged cosmonaut might try to fly the Vostok manually, Soviet engineers built in a system requiring that Gagarin enter a three-digit security code before he could assume the controls. The code was inside a sealed envelope, to be opened only in an emergency.
As they walked to the space capsule, Ivanovsky whispered the three-digit code in Gagarin's ear: 1-2-5. Gagarin smiled and said his flight instructor had already told him the numbers.
Ivanovsky helped Gagarin onto the ladder and into the cockpit of Vostok I, patted him on the helmet and then secured the hatch to the capsule. But a light indicating that the hatch was properly closed failed to go on.
In the midst of the countdown, Ivanovsky and two assistants hurried to replace 32 bolts by hand to secure the hatch.
"You should have seen yourself while you were working on the hatch," an unperturbed Gagarin later told Ivanovsky. "Your face had all the colors of tarnished metal."
Gagarin orbited once around the Earth, in a flight that lasted 108 minutes.
Less than a month later, Alan Shepard became the first American in space, during a 15-minute suborbital flight. It wasn't until Feb. 20, 1962, when astronaut John Glenn orbited the Earth three times, that the United States began to catch up with the Soviets in the space race.
No information about his survivors was available. Gagarin, who died in a plane crash in 1968 while on a routine military training flight, was soon hailed as a hero throughout the Soviet Union after his historic trip into space. But his arrival back on Soviet soil was hardly auspicious.
Wearing an orange space suit, he leaped out of the spacecraft, as planned, and parachuted into a remote part of rural Russia.
An elderly woman and her granddaughter who were nearby started to flee, fearing that a U.S. spy had landed in the Soviet hinterlands.
"Hey, where are you going?" Gagarin shouted. "I'm one of us!"