New solar panels unfurling on the International Space Station on 14th September 2006. The 11.6- metre-wide panels were installed on the new P3/P4 integrated truss segment two days earlier. This work was done over the course of three spacewalks by the crew of the space shuttle Atlantis during mission STS-115, which lasted from 9th-21st September. It was the first ISS construction mission since the loss of Columbia on 1st February 2003, although two Return to Flight missions had visited the ISS in July 2005 (STS-114) and July 2006 (STS-121). The construction work laid the foundations for the future expansion of the ISS.