upper surfaces with FRSI. Lightweight crew seats were installed and the Extended Duration Orbiter (EDO) package installed on OMDP-1 was removed to lighten Atlantis to better serve its prime mission of servicing the ISS. During the standdown period post Columbia accident, Atlantis went through over 75 modifications to the orbiter ranging from very minor bolt change-outs to window change-outs and different fluid systems. Atlantis was known among the shuttle workforce as being more prone than the others in the fleet to problems that needed to be addressed while readying the vehicle for launch, leading to some nicknaming it "Britney". Decommissioning NASA initially planned to withdraw Atlantis from service in 2008, as the orbiter would have been due to undergo its third scheduled OMDP; the timescale of the final retirement of the shuttle fleet was such that having the orbiter undergo this work was deemed uneconomical. It was planned that Atlantis would be kept in near-flight condition to be used as a spares source for Discovery and Endeavour. However, with the significant planned flight schedule up to 2010, the decision was taken to extend the time between OMDPs, allowing Atlantis to be retained for operations. Atlantis was subsequently swapped for one flight of each Discovery and Endeavour in the flight manifest. Atlantis had completed what was meant to be its last flight, STS-132, prior to the end of the shuttle program, but the extension of the Shuttle program into 2011 led to Atlantis being selected for STS-135, the final Space Shuttle mission in July 2011. Atlantis is currently displayed at the Kennedy Space Center Visitor Complex. NASA Administrator Charles Bolden announced the decision at an employee event held on April 12, 2011, to commemorate the 30th anniversary of the first shuttle flight: "First, here at the Kennedy Space Center where every shuttle mission and so many other historic human space flights have originated, we'll showcase my old friend, Atlantis". The Visitor Complex displays Atlantis with payload bay doors opened mounted at a 43.21° angle to give the appearance of being in orbit around the Earth. The mount angle pays tribute to the countdown that preceded every shuttle launch at KSC. A multi-story digital projection of Earth rotates behind the orbiter in a indoor facility. Ground breaking of the facility occurred in 2012. The exhibit opened on June 29, 2013. Crews A total of 156 individuals flew with Space Shuttle Atlantis over