Riding atop the huge crawler-transporter, space shuttle Discovery is expected to arrive at Launch Pad 39A between 11:30 a.m. and noon and then to be secured to the pad by about 1 p.m. today. It has been making a slow move to the pad this morning from the Vehicle Assembly Building at NASA’s Kennedy Space Center. Aug. 25 is the targeted launch date for Discovery’s STS-128 mission to the International Space Station.