Description These are video simulations depicting the Mars rover, carrying the Athena science payload, landing on and exploring the Martian surface. LAUNCH * Each Mars Exploration Rover will be launched on a Delta II launch vehicle from Cape Canaveral, Florida. * The Delta II stands about 100 feet tall and the rover is housed in a payload fairing that sits on top of the rocket. The first MER spacecraft launches in the daytime and the second one at night. * The Delta II engines produce more than 140000 pounds of thrust to break the grip of Earths gravity. * Nine solid rocket boosters ring the Delta launch vehicle. Six are ignited at launch and then discarded after they use up their fuel. The remaining three boosters are ignited in mid-air. * After the first stage of the rocket stops firing, it is discarded. Then the second stage engine ignites. * The payload fairing separates and reveals the MER spacecraft. * Small rockets are fired to spin up the third stage. The spinning motion helps to stabilize the spacecraft, acting like a gyroscope. * A burn of the third stage pushes the spacecraft out of Earth orbit and on a trajectory to Mars * The spacecraft must be de-spun so that it can achieve its proper cruise orientation. A set of weights called yo-yos are released from the spinning vehicle on flexible lines. They slow the spin of the spacecraft in much the same way that an ice skater decreases the velocity of a spin by extending his or her arms * The MER spacecraft separates from the <b>...</b>
