Space Shuttle Program: Space Shuttle Atlantis is launched on STS-115 to resume assembling the International Space Station. It is the first ISS assembly mission after the Columbia disaster back in 2003.

Space Shuttle Atlantis is a retired Space Shuttle orbiter vehicle which belongs to NASA, the spaceflight and space exploration agency of the United States. Atlantis was manufactured by the Rockwell International company in Southern California and was delivered to the Kennedy Space Center in Eastern Florida in April 1985. Atlantis is the fourth operational and the second-to-last Space Shuttle built. Its maiden flight was STS-51-J made from October 3 to 7, 1985.

STS-115 was a Space Shuttle mission to the International Space Station (ISS) flown by Space Shuttle Atlantis. It was the first assembly mission to the ISS after the Columbia disaster, following the two successful Return to Flight missions, STS-114 and STS-121. STS-115 launched from LC-39B at the Kennedy Space Center on September 9, 2006, at 11:14:55 EDT.

The process of assembling the International Space Station (ISS) has been under way since the 1990s. Zarya, the first ISS module, was launched by a Proton rocket on 20 November 1998. The STS-88 Space Shuttle mission followed two weeks after Zarya was launched, bringing Unity, the first of three node modules, and connecting it to Zarya. This bare 2-module core of the ISS remained uncrewed for the next one and a half years, until in July 2000 the Russian module Zvezda was launched by a Proton rocket, allowing a maximum crew of three astronauts or cosmonauts to be on the ISS permanently.

On Saturday, February 1, 2003, Space Shuttle Columbia disintegrated as it re-entered the atmosphere over Texas and Louisiana, killing all seven astronauts on board. It was the second and last Space Shuttle mission to end in disaster, after the loss of Challenger and crew in 1986.