 Lockheed Martin experienced delays during the production changes to make new external tanks with all the enhancements recommended by the Columbia Accident Investigation Board, making it impossible for them to produce two tanks for the STS-125 mission–one for "Atlantis", and one for "Endeavour" for an emergency rescue mission, if necessary–in time for the original August launch date.The first rollout to Launch Pad 39A occurred on 4 September 2008.On 27 September, the Science Instrument Command and Data Handling (SIC&DH) Unit on the Hubble Space Telescope failed.