Space has become a critical part of the United States' warfighting capability and requires that future space systems become more responsive than the current systems of reusable and expendable launch vehicles. The US military relies on space assets for communication, navigation, and intelligence, surveillance, and reconnaissance. Our adversaries also recognize our reliance on space techlogy and are moving forward to deny us the use of those systems. To reduce our vulnerability to those threats, the United States must have the ability to responsively replace, supplement, and service its space assets. Although the development and operational use of systems that will support the evolving mission areas of space control and force application will be subject to political and fiscal leadership decisions, they will also require responsive spacelift capabilities and it is prudent to include those considerations in spacelift planning. An analysis was begun in March 2003 to look at alternative affordable launch-vehicle systems and determine if one of those could satisfy all the requirements of the various missions.