NASA and a team of aerospace contractors reached a milestone in defining a second-generation reusable space transportation system with the release today of a status report on the first year of the effort. At present, some 15 different concepts are being hotly studied. The plan to develop a replacement for the Space Shuttle — a first generation system — is being carried out under NASA’s Space Launch Initiative (SLI). The announcement took place at NASA Headquarters in Washington, D.C. “We feel we’re on our way to enabling the development of a second generation reusable launch vehicle,” said Dennis Smith, program manager of the SLI at NASA’s Marshall Space Flight Center in Huntsville, Alabama.