Following STS-118 in August 2007, NASA managers decided to make modifications to the external tank to be used on STS-120, and modify the liquid oxygen feed-line brackets. The change involved a new low-density foam application, and thinner gaskets. Shuttle Program Managers decided to do this to reduce the foam loss from the area that had been noted since STS-114's "Return to Flight" mission in 2005. STS-118 had a small gouge on the belly of the orbiter due to a chunk of foam that impacted during launch in August 2007. The week of 17 September 2007, NASA managers decided to delay "Discovery's" rollover to the Vehicle Assembly Building (VAB), due to a hydraulic fluid leak from the right main landing gear strut. The strut repair was successfully completed on 19 September 2007. "Discovery" then moved to the VAB, and was mated to the External Tank and Solid Rocket Boosters. Perched atop the mobile launcher platform, "Discovery" arrived at Launch complex 39A on 30 September 2007.