Mike Griffin made another defense of his rocket vehicle projects in a speech (pdf) today in Washington: Griffin’s latest defense of Constellation - Space Politics.

Rand Simberg comments here: Making The Case One Last Time - Transterrestrial Musings

As Rand states, Griffin has never backed up his claims about the superiority of the Ares I by providing the documents from his group's study and stating clearly their initial assumptions. Why some NASA engineers, for example, would know with such certainty the relative safety of the Ares I, which is still in development, vs Atlas V, which has been flying for several years, remains a mystery. Furthermore, subsequent to NASA's decision to go with Ares I, Lockheed Martin has studied a crew version of the Atlas V and indications in conference papers are that LM engineers, who are after all the experts on the vehicle, believe it could be implemented safely.

The thing that stands out to me in the speech is that the Ares V heavy lifter is the real goal. The Ares I is crucial because it will develop and maintain production lines for various components needed for the Ares V, which will not begin flying till late in the next decade. Griffin's assumption that a heavy lift vehicle is absolutely essential for deep space exploration is one that should be revisited if the new administrator asks for a review of Constellation. The Ares V will be extremely expensive to develop and, since it will only fly 3 or 4 times a year at most, it will have enormous operational costs. Alternatives involve some combination of multiple launches of medium lift vehicles, on orbit storage of fuel, and in orbit assembly. A strong argument can be made that economies of scale with a high flight rate will bring launch costs down significantly and fuel depots/orbital assembly capabilities are required anyway for a genuine spacefaring infrastructure.

Unfortunately, because of jobs, politics and institutional inertia, NASA will probably continue with Ares I/V/Orion in the next administration, regardless of a new NASA chief. However, I expect that costs will eventually force their cancellation.