Discovery’s STS-128 mission has concluded, setting the launch date for Tuesday, Aug. 25 at 1:36 a.m. EDT08/24/09 01:58:28 AM...Main engine start (T-6.6 seconds) 01:58:35 AM...SRB ignition (LAUNCH) STS-128 Aug. 24 at 1:58 a.m The Space Shut…