STS-135

STS-135 closed a chapter of American spaceflight that had spanned thirty years. Since STS-1 in 1981, the Space Shuttle had flown 134 previous missions, built the International Space Station, deployed and repaired the Hubble Space Telescope, and survived two devastating losses of crew and orbiter. Atlantis's flight would be the program's last.

Commanded by Christopher Ferguson, the four-person crew, the smallest Shuttle crew in decades, launched on July 8, 2011, carrying more than four tons of supplies and spare parts to the International Space Station, a final resupply run meant to stock the station well ahead of the transition to relying entirely on smaller, uncrewed cargo vehicles for future deliveries. The small crew size reflected practical necessity: with no other Shuttle available to mount a rescue mission if problems arose, NASA planned for the crew to potentially need rescue via Russian Soyuz seats if Atlantis were damaged, and kept the mission's crew as small as safely possible.

Atlantis docked with the ISS on July 10, and the combined crews transferred cargo over the following days, filling the station with supplies intended to last through the early years of the post-Shuttle era. The astronauts also transferred failed hardware and unneeded equipment back to Atlantis for return to Earth, taking advantage of the Shuttle's unique cargo capacity one final time before it disappeared from NASA's fleet.

On July 21, 2011, Atlantis glided to a landing at Kennedy Space Center in the pre-dawn darkness, ending the Space Shuttle program after 135 missions, 30 years, and more than 542 million miles flown. Commander Ferguson's closing remarks to Mission Control, acknowledging the thousands of workers who had built and flown the Shuttle over three decades, marked the formal end of an era, as NASA turned toward developing new vehicles and increasingly toward commercial partners to carry astronauts to orbit.

STS-135 closed a thirty-year chapter in American spaceflight that had built the International Space Station, deployed and repaired the Hubble Space Telescope, launched countless satellites, and survived two devastating losses of crew, transforming and challenging NASA in equal measure.

The mission's final resupply run helped ensure the International Space Station could continue operating smoothly during the years-long gap before American crewed spacecraft flew again, a gap NASA bridged by relying on Russian Soyuz vehicles and, eventually, newly developed commercial spacecraft.

Pilot Douglas Hurley's later role commanding SpaceX's Demo-2 mission in 2020 created a direct symbolic thread between the Shuttle's final flight and the beginning of America's new era of commercial human spaceflight, connecting the program's end to what came next.