The air in the voids could have expanded due to the high temperatures generated during ascent thus breaking the foam. The reviews considered a rollback as an option since the defect could not be set right in the pad. Later, the tank was cleared for launch as is without any additional inspections. Launch attempts The first launch attempt was delayed by 24 hours due to weather concerns, including multiple weather violations in NASA's launch rules beginning over 2 hours before the scheduled launch. During the second attempt on Wednesday morning, a problem with a LH2 fill-and-drain fuel valve inside Discoverys aft compartment led to another scrubbing. The problem arose when sensors did not detect the closure of the valve when commanded to do so. The issue was thought to be with the sensors rather than the valve itself. After inerting the orbiter's tank, which involved draining it, tests were conducted on the valves. Despite the valves working normally, another delay was called for to have more confidence in the system, and to give the console operators who performed the test some rest. The launch team evaluated the issue, passing on a possible launch window on August 27, 2009, at 01:10 EDT. The launch was delayed until 23:59 EDT, August 28, 2009, to allow the engineers to be fully satisfied with the vehicle. Later the mission was cleared for launch which involved a flight rule waiver for cycling the valve and a discussion to analyze the test failure of an Ares-1 booster that was similar to the SRBs used for the mission. NASA feared another delay when storms formed near the Kennedy Space Center on August 28, 2009, but the weather cleared in time for a successful launch of Discovery at 23:59 EDT. Mission timeline August 28 (Flight Day 1 – Launch) After launch at 23:59 EDT, Discovery opened her payload bay doors. Once the doors were opened the crew deployed the Ku-band antenna and activated the Shuttle Remote Manipulator System (SRMS). Once the Ku-band antenna was deployed and activated, the crew then down-linked photos from the External Tank Umbilical Well Camera system, so controllers on the ground could see how the tank performed and how much if any foam was shed during ascent. August 29 (Flight Day 2 – TPS survey) During Discoverys first full day on orbit, the crew used the SRMS to grapple the Orbiter Boom Sensor System