"The current debate has nothing to do with technical/programmatic issues, it is completely politically motivated and being driven by a few people in the current administration, e.g., Lori Garver, NASA Deputy Administrator, Jim Kohlenberger, Office of Science and Technology Policy Chief of Staff, and Paul Shawcross, Chief of the Science and Space Branch at the Office of Management and Budget. Their objective is to cancel the "Bush" program and punish the states (Alabama, Texas) that "didn't vote for us anyway".
Keith's note: Of course, Scott Horowitz, who certainly seems to enjoy the breeze of that revolving door, is utterly hypocriticial when it comes to deriding decisions as being "political" in Washington DC (ohmygosh, politics in Washington. I wonder who knew this was going on!?) given that he is still a registered lobbyist for ATK (paid $30K in 2008 and 2009, and $10K thus far in 2010), and has been interacting with NASA in that capacity. Does he bother to disclose this when he posts these little one-sided missives? Of course not. Pot, kettle, black, Scott.
Meanwhile, back in our universe ...
"The Constellation program has not yet developed all of the elements of a sound business case needed to justify entry into implementation. Progress has been made; however, technical and design challenges are still significant and until they are resolved NASA will not be able to reliably estimate the time and money needed to execute the program. In addition, cost issues and a poorly phased funding plan continue to hamper the program. Consequently, NASA is changing the acquisition strategy for the Orion project as the agency attempts to increase confidence in its ability to meet a March 2015 first crewed launch. However, technical design and other challenges facing the program are not likely to be overcome in time to meet the 2015 date, even with changes to scope and requirements."