In the Payload Hazardous Servicing Facility, the shipping container is lifted off the components of Mars Exploration Rover-1, the aershell and cruise stage. Each rover , aeroshell and lander will undergo a full mission simulation while at KSC. All flight elements will then be integrated. After spin balance testing, each spacecraft will be mated to a solid propellant upper stage booster that will propel it out of Earth orbit. The rovers will serve as robotic geologists to seek answers about the evolution of Mars, particularly for a history of water. The rovers will be identical to each other, but will land at different regions of Mars. Launch of the MER-1 is scheduled for May 30. MER-2 will follow June 25.