Garry Lyles, Chief Engineer, Marshall Space Flight Center, AL

Garry Lyles: It’s the heavy launch system that is designed to take humans and cargo beyond lower Earth orbit. It is the next big capability with the Orion MPCV (Multi-Purpose Crew Vehicle). The Space Launch System is being designed as an evolvable technology. It’s starting out with capability of [carrying] 70 metric tons to lower Earth orbit, which is kind of a reference point for us. It is a drop-off point that allows us to design against a certain set of requirements. Then we have an evolved capability to greater than 100 metric tons, and then greater than 130 metric tons for the future long-term missions and missions that require capability that we’ve really never had before: the capability to send humans to Mars.