STS-119 was a space shuttle mission that launched on March 15, 2009. The primary goal was to deliver the S4 truss segment to the International Space Station (ISS). This truss was essential for supporting solar arrays, which provide power to the station. The mission was conducted by the Space Shuttle Discovery, which completed a total of five spacewalks during the mission. STS-119 lasted 13 days, and the crew successfully installed the truss, enhancing the ISS's capabilities for future missions and research.