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The final flight of the Space Shuttle Discovery. STS-133 (Space Transportation System - mission 133) clears the launch tower of Launch Pad 39A from the Kennedy Space Center in Cape Canaveral, Florida. The late afternoon sun backlights the expanding exhaust plumes from the two solid rocket propellant engines. This mission marked both the 133rd flight of the Space Shuttle program and the 39th and final flight of Discovery.