The Apollo-Soyuz Test Project brought Soviet cosmonauts and Nasa astronauts together in the first international human spaceflight.
Some 225km above France, American astronauts opened a spacecraft hatch and found themselves face to face with cosmonauts from the Soviet Union.
“Glad to see you,” Colonel Alexei Leonov spoke in accented English
to Brigadier General Thomas Stafford of Nasa.
“Ah, hello, very glad to see you,” Stafford responded in his own accented Russian.
The two men then shook hands.
Today, Russian and American astronauts routinely share rides to the International Space Station, no matter the geopolitical conflict that divides their nations. But in the summer of 1975, seeing two men from rival nations greet each other in orbit across a bridge between their docked spacecraft was a powerful and unprecedented gesture witnessed by millions on the world spinning below.
The handshake, which occurred 50 years ago on July 17, defined the Apollo-Soyuz Test Project, the first international human spaceflight. That simple symbol of partnership between bitter competitors remains an enduring legacy of the mission.
“It’s amazing to think that two diametrically opposed countries with different systems and cultures, essentially ready to destroy each other, can somehow co-operate and do this highly technical, complicated mission,” said Asif Siddiqi, a professor of history at Fordham University and an expert on Russian space history.
A generation after the orbital handclasp, the Soviets and the United States would come together to build the ISS. The ageing space outpost’s days are finite, and there are no immediate plans for Russia and the US to sustain their co-operation in human spaceflight. The US also sees itself as competing with China for dominance in space. But experts like Siddiqi see reasons for hope on the 50th anniversary of the Apollo-Soyuz mission.
“Whenever people tell me that this would never happen today, I always think, Well, that’s what people said in the late ’60s,” Siddiqi said.
“Androgynous” dock
Early in the space age, as America raced to catch up to the Soviet Union, a partnership in space had been proposed. In September 1963, speaking before the United Nations General Assembly two months before his assassination, President John F. Kennedy floated a joint mission to the moon.
“Why therefore should man’s first flight to the moon be a matter of national competition?” he asked. “Surely we should explore whether the scientists and astronauts of our two countries – indeed of all the world – cannot work together in the conquest of space.”
This dream was deferred, and the US would overtake the Soviets in the moon race with the successful Apollo 11 mission in 1969.
Oddly, the American moon landing may have created a new window for co-operation. Public support for the Apollo missions fell, and the programme was cut short after the Apollo 17 mission in 1972. That left the US space programme without an immediate objective.
In parallel, both nations’ reputations were tarnished abroad, the Soviet Union by its invasion of Czechoslovakia, and America by its involvement in the Vietnam War. That created an additional motivation to jointly reassert each country’s status atop the global hierarchy.
“They needed to lift themselves up and cooperate with each other to show the rest of the world: We are as super and as great as ever before. We’re doing things which no country can do in a similar capacity,” said Olga Krasnyak, an associate professor of international relations at the National Research University Higher School of Economics in Moscow.
This mutually recognised opportunity for prestige led to tentative talks between the country’s officials in 1970. From the get-go, it was clear that the mission faced immense diplomatic, technical and cultural obstacles. There was no smooth glide path to launch.
“How do we communicate with people who speak entirely different languages, and who think differently about engineering and problem-solving?” Brian C. Odom, Nasa’s chief historian, said. “On paper, it seems easy. You launch, we launch, we come together, we shake hands, we go our separate ways. But making that happen, where you don’t have five people dying in orbit, is incredibly difficult.”
The sudden switch from enemies to partners, at least in this limited case, caused whiplash for the public and politicians alike (a scenario that was dramatised in the Apple TV alternative history series For All Mankind).
Zbigniew Brzezinski, who later served as Jimmy Carter’s national security adviser, criticised the Nixon and Ford administrations for the mission, calling it a “technological giveaway”. Soviet space officials, who long worked in secrecy, had to overcome wariness about loosening the flow of information to an adversary. The country’s diplomats had to ensure that plans could be discussed without divulging anything sensitive to national security.
Both sides were suspicious of the safety of the other’s flagship spacecraft. The three astronauts selected for Apollo 1 perished in a fire during a rehearsal in 1967, while the three cosmonauts of Soyuz 11 died in space in 1971 when their cabin depressurised. Snipes about the superiority of one side’s spacecraft over the other rankled insiders of the mission. American astronauts were used to a much more hands-on guidance system with Apollo, whereas Soyuz was largely automatic and controlled from the ground.
The vehicles even used different atmospheres in their interiors. Soyuz simulates the familiar conditions of Earth, with a nitrogen-oxygen air mixture and a pressure equivalent to our planet at sea level. Apollo, in contrast, used a pure oxygen atmosphere at a much lower pressure.
This discrepancy was solved by the development of a docking module with airtight hatches at each end. Once the module connected the two craft, crew members from one vehicle could enter, ensuring that both hatches were closed while it pressurised to match conditions of the other side. When that process was complete, the hatch to the other vehicle could be opened, allowing crews to safely enter without risking “the bends,” a condition caused by rapid depressurisation.
For this particular mission, the Soyuz was kept at a lower pressure than normal to ease transitions between vehicles. The docking module was also purposefully designed to be androgynous to ensure that neither spacecraft was perceived as “female,” or passive.
As the mission planners navigated these headaches, a deep and abiding friendship flourished between the astronauts and cosmonauts. The Apollo side, headed by Stafford, also included Donald “Deke” Slayton and Vance Brand. Leonov flew on the Soyuz side with Valery Kubasov.
The crews learned each other’s languages, though Leonov jokingly called Stafford’s drawling pronunciation “Oklahomski”. They trained together at Nasa Johnson Space Center in Houston and at Star City, the Russian space centre outside Moscow. During these meetings, the space travellers hunted, drank and partied together. They shared steam baths and got into snowball fights.
The two commanders remained particularly close for the rest of their lives: Leonov helped Stafford adopt two children from Russia, and Stafford gave a eulogy in Russian (or, rather, Oklahomski) at Leonov’s funeral in 2019.
The crews were “setting an example, by being friendly and demonstrating co-operation,” said Brand, the last living member of the mission, in a 2000 interview with Rebecca Wright of Nasa’s Johnson Space Center Oral History Project.
“We actually came to have a very close relationship with the Soviet crew,” he added.
Strawberry juice and borscht
Against all odds, the crews finally reached their launchpads during the summer of 1975. On July 15, the Soyuz crew blasted off from Baikonur Cosmodrome in Kazakhstan, followed by the Apollo crew, which launched about seven hours later from Kennedy Space Center in Florida.
The lead-up to docking was relatively smooth, though the Apollo crew discovered a “super Florida mosquito” had stowed away with them, and Stafford joked that a juice spill had turned the Apollo into a “strawberry-coloured spacecraft”.
The spaceships successfully docked at 12.12pm Eastern time July 17, high above the Atlantic Ocean. Hours later, the historic handshake was broadcast live to millions of viewers. The mission even inspired a cocktail called the Link Up, with equal parts Southern Comfort and vodka mixed with lime and ice, served at London’s Savoy Hotel.
The crew spent the next two days exchanging gifts, dining together (including borscht toasts), listening to music and conducting experiments. The ships parted ways July 19.
After all the mutual worries about spacecraft safety, it was Apollo that ended up experiencing a serious incident, as toxic fumes filled the capsule during re-entry. Brand lost consciousness and the crew was hospitalised after splashdown.
Despite this frightening conclusion of the mission, the astronauts quickly recovered and the mission was hailed as a diplomatic and technical success.
“A little bit messy”
A second Apollo-Soyuz mission was planned, but it never panned out. US-Soviet tensions rose again during the late 1970s and into the 1980s. The countries did not directly team up again for years. However, both superpowers fostered new collaborations with their allies. During the 1980s, Nasa space shuttle crews included Canadian, European and Japanese astronauts, while the Soviet Union launched cosmonauts who came from Cuba, Poland, Vietnam, Afghanistan and other countries.
After the collapse of the Soviet Union, Americans and Russians again joined forces in space, first aboard the Mir space station in the early 1990s. The American-Russian partnership is now the backbone of the ISS, which has remained continuously inhabited since the year 2000.
That outpost is in its twilight years. Russia is discussing building its own separate successor space station, and the US is seeding commercial outposts in orbit – efforts that can make Apollo-Soyuz seem like a distant memory.
But Krasnyak, the Russian international relations expert, said that the legacy of this mission, and co-operative space exploration in general, remains important to Russians 50 years later. Whether the US and Russia partner on future human spaceflights or not, she noted that the two powers continue to be world leaders shaping international deliberations on space.
Siddiqi, the historian of Russian spaceflight, views the 1975 US-Soviet mission as a forerunner for the complex international partnerships that characterise modern spaceflight, even if it’s in a “roundabout way”.
“It was a little bit messy, but the road leads back to Apollo-Soyuz,” he said. “Other historians would see it differently, as a kind of rupture or as a one-off, but I see a lot of continuities.”
Odom, Nasa’s chief historian, does not see Apollo-Soyuz as a direct progenitor of the ISS, or of other subsequent space collaborations. From his perspective, the mission’s legacy is grounded more in the context of a time when two feuding powers extended an olive leaf into orbit, with repercussions for how their citizens viewed each other back on Earth.
“The people who were involved come away from it thinking about what co-operation really might mean,” Odom said. “If we can co-operate with the Soviet Union in this way, we can co-operate with anyone.”
The direct communication and interpersonal relationships were a powerful spinoff from the mission, Odom added.
“The thing that they really come away with is that ‘oh, you’re human beings just like us,’” he said. “You’re not the monsters that we imagined or feared that you would be. You’re just people trying to do a job and go about your daily life.”
This article originally appeared in The New York Times.
Written by: Becky Ferreira
©2025 THE NEW YORK TIMES
