World Space Week: A Look at the Nations and People Who Have Journeyed Beyond Earth

Every year from October 4 to 10, the United Nations coordinates World Space Week, a global observance designed to highlight how space science and technology contribute to the betterment of life on Earth. The occasion brings together schools, space agencies, museums and astronomy clubs, which organize stargazing events, science lessons, exhibitions and public conversations with astronauts and researchers. The dates themselves are deliberately symbolic, marking two milestones that helped define the modern Space Age.

The first of those milestones occurred on October 4, 1957, when the Soviet Union placed Sputnik 1 into orbit, making it the first artificial satellite to circle the planet. That single achievement not only opened the Space Age but also ignited a fierce technological and ideological contest with the United States. A decade later, on October 10, 1967, the Outer Space Treaty came into force, a landmark agreement signed by the United States, the United Kingdom and the Soviet Union that declared space a domain to be explored and used for peaceful purposes and barred any nation from claiming it as sovereign territory.

The push to send humans beyond Earth's atmosphere began in earnest on April 12, 1961, when Soviet cosmonaut Yuri Gagarin became the first person to travel into space. Aboard the Vostok 1 capsule, Gagarin completed a single orbit at roughly 27,400 kilometers per hour (17,025 miles per hour) during a flight lasting 108 minutes, ejecting from the spacecraft before landing by parachute. His mission proved that the human body could withstand the rigors of launch, weightlessness and re-entry, handing the Soviet Union a significant early advantage in the Cold War competition.

The next major leap came less than two years after the Outer Space Treaty took effect, when NASA's Apollo 11 mission carried the first humans to the lunar surface. On July 20, 1969, Neil Armstrong stepped onto the moon, becoming the first person to walk on another world and fulfilling a goal set by U.S. President John F. Kennedy earlier in the decade. That achievement remains a defining moment in the history of exploration and a benchmark against which subsequent human spaceflight programs are measured.

One question that complicates any tally of space travelers is where, exactly, space begins. There is no universally accepted boundary. Most international organizations rely on the Karman line, set at 100 kilometers (62 miles) above Earth, while the U.S. military, NASA and the Federal Aviation Administration treat 80 kilometers (50 miles) as the threshold. Though the difference sounds minor, it can determine whether certain high-altitude flights are officially counted as reaching space.

By the Karman line standard, at least 746 people drawn from 52 countries have journeyed to space, a figure that includes career astronauts as well as private individuals who paid for the experience. The count is complicated by dual nationalities and by travelers who flew on behalf of nations that no longer exist, such as the former Soviet Union, whose cosmonauts are often grouped together with those of modern Russia.

Two nations continue to dominate the historical record. The United States has sent 369 people to space, while the Soviet Union and Russia together account for 138. China, which became the third country capable of launching humans on its own rockets, has sent 29. The remaining spacefarers are distributed among dozens of other countries, a reflection of both the spread of spaceflight capability and the growth of international cooperation aboard orbiting laboratories.

The demographics of those who reach space remain heavily skewed. Of the 746 individuals who have flown, only 112, roughly 15 percent, have been women, meaning about one in seven space travelers is female. The trailblazer was Soviet cosmonaut Valentina Tereshkova, who flew in June 1963. It took the United States another two decades to follow suit, with Sally Ride's first flight in June 1983.

That imbalance is slowly improving, in large part because of the rise of commercial spaceflight. More than half of all women who have traveled to space since 2020 did so as paying passengers or guests aboard Blue Origin's suborbital rocket. Private ventures have thus begun to reshape not only who gets to fly but also the reasons people go, shifting the profile of the typical space traveler away from government-selected professionals.

The typical space traveler, according to data on those who have flown, has tended to be in their 30s, though the full range spans from younger passengers on recent commercial flights to some of the oldest individuals ever to reach orbit. That broadening age profile underscores how access to space is no longer confined to a small cadre of military and scientific personnel chosen through rigorous national selection programs.