Launch Target: May 12, 2009 Orbiter: Atlantis Mission Number: STS-125 (126th space shuttle flight) Launch Window: 60 minutes - rendezvous dependent Launch Pad: 39A Mission Duration: 11 days Landing Site: KSC Inclination/Altitude: 28.5 degrees/304 nautical miles Primary Payload: Hubble Space Telescope Servicing Mission .