CRS-4

Mission Summary: This will be flight four of five for the Dragon as part of the CRS program. The launch sequence begins at T-30 seconds, where the internal computer takes control of the flight and the vehicle starts up. Once the sequence reaches T-3 seconds the 9 main engines of the vehicle will ignite and come to full thrust. Once the count reaches T-0 the hold down systems release the vehicle and the main ascent sequence begins. The first stage will continue to burn until the allotted ascent fuel is used, at which point the first stage will jettison. The second stage will ignite and continue the ascent to orbit. Meanwhile the first stage will unlock the reserve fuel tank, turn around, then ignite 3 of the 9 engines to reverse the trajectory back to the launch site. After the burn the vehicle then will flip around once again and extend the air brakes to slow the craft and give more control. Once at the proper altitude the center engine ignites and the landing legs extend. The center core then touches down. By that time the craft will be in orbit. Dragon then will rendezvous with the ISS and remain there for 30 days. After that time the crew will undock aboard the Dragon and return to the surface on parachutes. The landing will be cushioned by the thrust of the SuperDraco engines. After splashdown the vehicle will be recovered.