Friday will feel like launch day for the seven astronauts of Discovery’s STS-128 mission. Almost. The crew will suit up in their orange launch-and-entry ensembles and climb into the Astrovan at NASA’s Kennedy Space Center in Florida. They’ll get taken out to Launch Pad 39A and technicians will help them into their seats. The countdown clock will roll backward and the astronauts will run through their launch-day protocols of radio checks and liftoff procedures. Then, it’ll all be over. The clock will stop and the crew will practice a few skills they hope to never need: emergency evacuation. Called the Terminal Countdown Demonstration Test, it’s a routine exercise for shuttle crews. It also caps the astronaut’s visit to Kennedy that began Wednesday. As for Discovery, the “Leonardo” supply module full of supplies and equipment for the International Space Station was being loaded into its payload bay Thursday. With launch targeted for Aug. 25, technicians at Kennedy will spend the next couple of weeks prepping the craft for its real liftoff.