NASA JSC Memo: Commercial-Crew Vehicle Transition Concepts 1 March 2010
"The President's 201 1 Budget Proposal which was unveiled on February 8, 2010, places an emphasis on commercial vehicles "to provide astronaut transportation to the International Space Station (ISS), reducing the sole reliance on foreign crew transports and catalyzing new businesses and significant new jobs." The following paper provides recommendations for the transition to a commercial-crew vehicle to the ISS which leverages the experience gained in the operation of the Space Shuttle, the ISS, and in the design of Constellation."



"The notion is that an evolvable shuttle-derived HLV could begin with a core that might be an in-line configuration of 4-segment SSRBs, coupled to an ET-sized core segment (strengthened and with a boat-tail at the bottom holding SSMEs, and a payload attachment/inter-stage carrying an accelerated Orion with LAS attached) which would become the "government-operated" LEO/ISS support capability, with a target IOC of 2013."
As good a description of DIRECT as one can get w/o using the 'D' word! Let's see. I think 'D' v.1.0 came out in 2006...