Like any large-scale space development program, NASA’s Ares 1 and Ares 5 launchers – designed to launch astronaut crews and Moon-bound cargo, respectively – pose daunting challenges, both technical and financial. If that weren’t enough, NASA also must contend with constant second-guessing of its chosen space exploration transportation architecture – something that threatens to erode political support for the entire effort.

First, there were those who were unhappy with NASA’s choice of a space shuttle-based approach over one that would utilize hardware from the U.S. Air Force’s Evolved Expendable Launch Vehicle (EELV) program. Disgruntled proponents of the EELV-derived solution continued to push that concept – some quietly, some less so- long after NASA made its decision, much to the irritation of senior agency officials.

Now, just as that controversy seems to have subsided, along comes a group touting a different shuttle-derived solution, one that advocates argue is – please pardon the expression – faster, better and cheaper than Ares.

Publicly led by design technology company TeamVision Corp. and allegedly including numerous NASA engineers working on their own time, the group says NASA is not giving their Direct 2.0 transportation concept a fair hearing, and is taking its case to the press. The Orlando Sentinel, in a June 22 article – beneath the scandal- suggesting headline: “NASA remains silent on rocket that could save the Cape” – said Direct 2.0, also known as Jupiter, would preserve thousands of jobs in Florida and accused the space agency of “trying to stifle debate about alternatives” to the current Ares designs.

It is no secret the transition from the space shuttle to the Orion crew capsule and its Ares 1 launcher is going to result in the elimination of some 3,000 jobs in and around NASA’s . Unfortunately, this is part of the price of progress; NASA simply cannot afford to run its human spaceflight program the way it has for the past 27 years.

NASA, for its part, is doing everything it can to mitigate the job losses at the Kennedy. There will be new jobs associated with Orion and Ares 1 and 5, for example, and NASA Administrator Mike Griffin recently proposed making the center responsible for sustaining engineering for the new vehicles.

NASA disagrees with the assertion that Direct 2.0 is superior to Ares. The space agency has produced an internal study that concluded the alternative vehicles do not meet the agency’s performance specifications for a return of astronauts to the Moon. NASA also said claims that the Jupiter rockets could be fielded more quickly and at less cost than Ares are not backed up with concrete evidence.

TeamVision Chief Executive Stephen Metschan naturally questions the objectivity of NASA’s analysis and is calling for an independent review of Direct 2.0 versus the Ares architecture, with the aim of convincing the next Congress and presidential administration to set NASA on a new course as early as next year.

It is perfectly understandable that Mr. Metschan would be suspicious that NASA’s analysis was unfairly skewed in favor of Ares. But by the same token, it would be nave not to view the claims of Direct 2.0’s advocates with skepticism; as the saying goes, if something sounds too good to be true, it probably is. One has to wonder, for example, how this approach would save all those jobs at the and yet still be cheaper to develop and operate than the Ares vehicles.

Mr. Metschan’s request for an independent analysis might seem reasonable, but at this stage of the game it’s asking too much, regardless of the concept’s merits: Ares development is well under way already; a test flight of a prototype vehicle, Ares 1-X, is scheduled for spring 2009.

To be sure, technical issues have arisen on Ares, but to put the development effort on hold to review a potential alternative would at the very least cost hundreds of millions – if not billions – of dollars and delay the fielding of the space shuttle’s replacement for who knows how long. Scrapping Ares and starting over would mean writing off the time, effort and money expended to date, all for a concept that is sure to have its own costly technical hiccups and flaws hidden beneath the hype. That would be a true scandal.

There will always be technical disagreements among capable, well-intentioned engineers, but the time always comes to stop debating and start building. Ares is well past that point; if Congress and the White House cannot trust NASA’s judgment, then it is time to rethink the structure of the entire civil space program.

One way to kill a big program, especially during times of political and economic uncertainty, is to subject it to endless studies. The danger here is real, and if Ares dies it has the potential to take with it the entire space exploration strategy as laid out by President George W. Bush in the wake of the tragedy, leaving NASA’s human spaceflight program without a vision for the future. Anyone in Congress and the White House who does not want that to happen should resist the siren song of Direct 2.0.