Fifty Years of Human Spaceflight

Piercing Soviet Secrecy

U.S. officials needed timely and accurate information on the Soviet space program, but it was difficult to obtain because of the secrecy surrounding it. Only the U.S. intelligence agencies could provide the information needed. Their worldwide network of ground stations, ships, and aircraft tracked Soviet rockets and spacecraft and intercepted signals sent between them and ground controllers. Analysts evaluated the data to assess the current and future Soviet space program.

Intercepting Soviet Signals

Soviet spacecraft with animal and human passengers transmitted a variety of data, including biomedical information such as body temperature, heart and respiration rates, and blood pressure. Many capsules sent television pictures of the animal or human. Cosmonauts and ground controllers also talked with one another.


Laika's Heartbeat

The first Soviet biomedical data intercepted from space was from Laika, the dog Sputnik 2 carried into orbit in November 1957. These are excerpts of the U.S. tapes that recorded Laika's heartbeat (top) and blood pressure (bottom).
National Security Agency

Laika, the first living being launched into orbit.

Laika, the first living being launched into orbit. She didn't return from her mission, but she paved the way for the first human in space.

This is one frame of the television pictures of Yuri Gagarin.

This is one frame of the television pictures of Yuri Gagarin that the United States intercepted and processed early in his flight. Based on these photos and intercepted voice transmissions between the cosmonaut and ground controllers, the U.S. government knew—even before Gagarin landed—that the Soviets had successfully placed a human in space.
National Security Agency

Other Sources of Intelligence

U.S. intelligence agencies collected information on the Soviet space program by other means as well. These included reviewing public information sources, tracking of Soviet spacecraft, and overhead photography.


An April 1962 Izvestia article on cosmonauts.
An April 1962 Izvestia article on cosmonauts.

U.S. intelligence agencies monitored the Soviet press and radio broadcasts for information on the space program. However, the media was tightly controlled. The few public statements—even those announcing successful missions—were often vague and incomplete.

The Millstone ultra-high frequency radar

This is the Millstone ultra-high frequency radar built by Lincoln Laboratories in Westford, Massachusetts, in the mid-1950s. It was one of several U.S. radars around the world that tracked Sputnik 1 and other Soviet spacecraft. Modern radars at the site still conduct space surveillance today.
MIT Lincoln Laboratory, Lexington, Massachusetts

A launch pad in the Tyuratam complex

A launch pad in the Tyuratam complex, photographed in 1959 by a U-2 spy plane. The Soviets used Tyuratam to launch all their crewed flights and many other spacecraft. The site was a frequent target of U-2s from 1956 to1960 and of photoreconnaissance satellites thereafter.

Reporting to U.S. Policy Makers

U.S. intelligence agencies published their evaluations of the Soviet space program in National Intelligence Estimates and many other reports provided to high-level civilian and military officials. NASA's leadership regularly received these and other intelligence reports to learn what the U.S.S.R. was doing in space.

CIA Estimate - Soviet Space Program

This National Intelligence Estimate—the last one published before Yuri Gagarin's flight—predicted the U.S.S.R. would be capable of sending a human into orbit and recovering him from space within the next year. Monitoring of subsequent Soviet test flights confirmed this assessment.
Central Intelligence Agency

CIA Estimate - Soviet Space Program