At long last, U.S. President Barack Obama has formally set in motion the process that will determine once and for all whether NASA’s current space shuttle replacement plan will survive his administration. In unveiling its proposed NASA budget profile for the next five years, the White House announced the creation of an independent panel that will weigh the merits of the current architecture, featuring the Orion crew capsule launched by the shuttle-derived Ares 1 rocket, against alternatives that presumably include a scaled-back version of Orion lofted by an existing Evolved Expendable Launch Vehicle (EELV) rocket.

The panel, led by Norm Augustine, the former chief executive of Lockheed Martin, is expected to report back its findings in 90 days.

Many no doubt believe the outcome is all but assured; that Mr. Augustine’s panel will determine that the EELV-launched Orion scheme is the least expensive and least risky of the two known options, thereby giving the White House the technical authority it needs to make the changes it has wanted all along. Indeed, given the guidelines the panel has been given for its review – most notably that it must adhere to NASA’s new budget profile while minimizing the looming five-year gap between the shuttle’s planned 2010 retirement and the debut of the new system – it is easy to envision the members reaching that conclusion: Fielding Orion and Ares 1 by 2015 was going to be a challenge under the budgets proposed by the previous administration, and Mr. Obama’s out-year budget profile is some $3 billion lower.

Mr. Augustine says his panel will not limit the scope of its recommendations to what is strictly affordable under the administration’s budget profile. In other words, if the best and most logical solution costs more money, the panel will say so.

This is appropriate, particularly given the fact that supporting astronaut missions to the Moon and other destinations beyond low Earth orbit is among the NASA objectives that the panel has been directed to take into consideration. While the shuttle needs to be replaced under any circumstances, this administration must not take its eye off NASA’s long-term strategic goal.

NASA recently tempered its lunar ambitions, backing away from previous statements about establishing a permanent outpost and talking up the merits of relatively short-duration visits. Former NASA Administrator Mike Griffin, on whose watch the current architecture was devised, cited the sustained presence as a driving requirement for Orion as currently scaled, the reason being that the vehicle would have to loiter in lunar orbit for months before bringing the crews back home. This, in turn, necessitates a powerful launcher like Ares 1, whose core stage is based on the space shuttle’s giant solid rocket boosters. It may well be that an Orion capsule small enough to launch atop an existing EELV is sufficient to support astronaut excursions to the lunar surface. Should the Augustine panel’s analysis conclude that this is indeed the case, and that such a system can be developed at far less cost than the Orion-Ares 1 combo – with a potential side benefit of freeing up cash for commercial space station logistics services – so be it.

Mr. Augustine, one of the space industry’s trusted wise men, can be counted on to take a fresh and unbiased look at the available alternatives. Nonetheless, given the stakes involved, there are bound to be suspicions that the deck has been stacked one way or the other. It therefore is imperative that this review be conducted in as open a manner as possible, something the Obama administration’s mantra of transparency dictates in any case. Rumors of staggering cost growth and intractable technical problems on Ares 1 have been swirling for months, for example, but to date nobody has produced any firm evidence of issues that are outside the norm for space development programs. One of the most – if not the most – critical tasks of Mr. Augustine’s panel will be to come up with a credible, independent cost and schedule estimate for Ares 1, one that can be backed up with documentation.

The panel also will need to clearly explain the implications dropping Ares 1 would have for the heavy-lift vehicle everyone agrees is needed to support astronaut missions to destinations beyond low Earth orbit. The vehicle NASA has in mind for that job is the Ares 5, which shares major components in common with the Ares 1, including the solid rocket boosters and the J-2X upper stage engine. If Ares 1 goes away, development work on this hardware will be have to be shifted to the Ares 5 program, raising its price tag considerably.

There were valid reasons for NASA’s shuttle-replacement hardware choices, particularly in light of the agency’s broader exploration mandate. But it also is true that NASA’s budget outlook is not the same as when the architecture was devised. Mr. Augustine’s challenge over the next 90 days is not only to point the way forward for NASA but also to present and support its recommendations in such a way that they do not lend themselves to the incessant second-guessing that can be just as lethal to good programs as to bad.