Jeff Faust has a nice write up on the DC/X reunion. The DC/X was a prototype rocket vehicle that operated the way God and Robert Heinlein intended, VTOL (Vertical Take-off Vertical Landing). It was a part of the Strategic Defence Initiative to support frequent, low cost access to space and was killed by anti-military elements in the federal bureaucracy. NASA is now busy reinventing expendable launch vehicles.

DC/X did prove the concept viable and others are working to build upon its legacy. Armadillo Aerospace and Blue Origin are entrepreneurial efforts to develop economical VTOL launch vehicles in the X Program tradition, build some prototypes, fly them to find the weaknesses, improve them and fly again.