The Space Launch System Mobile Launcher. Built for the Ares family of boosters, the Mobile Launcher, after the cancellation of the Constellation program, seemed destined for the scrapyard when fate intervened. As NASA began development of the new heavy lift vehicle, Congress ordered that shuttle facilities, matured shuttle technologies and existing flight hardware were to be reused wherever possible to minimize the cost impact of the new design. Concerning the ML, it was determined that, with minor modifications to the tower and platform, several vehicle types and vehicle configurations could be accommodated. The task it was designed for was again in its future. The contract for the construction of the Mobile Launcher was awarded to Hensel Phelps of Orlando, Florida. The mobile launcher consists of the main support structure that comprises the base, tower and facility ground support systems, which include power, communications, conditioned air, water for cooling, wash-down, and ignition over-pressure protection. The tower of the Mobile Launcher has numerous platforms for personnel access and is 390 feet tall. Its construction occurred at the mobile launcher park site area located north of the Vehicle Assembly Building at the Kennedy Space Center in Florida. Special launch tables, configured for different launch vehicles, will extend the applications of the tower and platform over several vehicle types. The Space Launch System, or SLS, will use the repurposed mobile launcher. The SLS is designed to carry the Orion Multi-Purpose Crew Vehicle, as well as important cargo, equipment and science experiments to Earth's orbit and destinations beyond. Additionally, the SLS will serve as a back up for commercial and international partner transportation services to the International Space Station. The SLS rocket will incorporate technological investments from the Space Shuttle Program and the Constellation Program in order to take advantage of proven hardware and cutting-edge tooling and manufacturing technology that will significantly reduce development and operations costs. It will use a liquid hydrogen and liquid oxygen propulsion system, which will include the RS-25D/E from the Space Shuttle Program for the core stage and the J-2X engine for the upper stage. SLS will also use solid rocket boosters for the initial development flights, while follow-on boosters will be competed based on performance requirements and affordability considerations. The SLS will have an initial lift capacity of 70 metric tons. That's more than 154,000 pounds, or 77 tons, roughly the weight of 40 sport utility vehicles. The lift capacity will be evolvable to 130 metric tons -- more than 286,000 pounds, or 143 tons -- enough to lift 75 SUVs. The first developmental flight, or mission, is targeted for the end of 2017. This specific architecture was selected, largely because it utilizes an evolvable development approach, which allows NASA to address high-cost development activities early on in the program and take advantage of higher buying power before inflation erodes the available funding of a fixed budget. This architecture also enables NASA to leverage existing capabilities and lower development costs by using liquid hydrogen and liquid oxygen for both the core and upper stages. Additionally, this architecture provides a modular launch vehicle that can be configured for specific mission needs using a variation of common elements. NASA may not need to lift 130 metric tons for each mission and the flexibility of this modular architecture allows the agency to use different core stage, upper stage, and first-stage booster combinations to achieve the most efficient launch vehicle for the desired mission. The Space Launch System will be NASA's first exploration-class vehicle since the Saturn V took American astronauts to the moon over 40 years ago. With its superior lift capability, the SLS will expand our reach in the solar system and allow us to explore cis-lunar space, near-Earth asteroids, Mars and its moons and beyond. We will learn more about how the solar system formed, where Earth's water and organics originated and how life might be sustained in places far from our Earth's atmosphere and expand the boundaries of human exploration. These discoveries will change the way we understand ourselves, our planet, and its place in the universe. The U.S. Space Launch System (SLS) will provide an entirely new capability for human exploration beyond Earth orbit. It also will back up commercial and international partner transportation services to the International Space Station. Designed to be flexible for crew or cargo missions, the SLS will be safe, affordable, and sustainable, to continue America’s journey of discovery from the unique vantage point of space.