The idea of the U.S. government outsourcing astronaut transport to the private sector, which seemed farfetched not so long ago, has won a strong endorsement from an expert panel tasked by the White House in May to review NASA’s human spaceflight plans.

In a summary report released Sept. 8, the Augustine committee, named after its chairman, former Lockheed Martin chief executive Norm Augustine, outlined five options for NASA’s spaceflight future, three of which rely on the commercial sector for delivering crews to the international space station after the space shuttle retires in the next year or so. The report notes that commercially procured services have the potential to save money in both the near and long term while narrowing the post-shuttle gap in U.S. human spaceflight capability.

Entrepreneurial spaceflight advocates say the findings validate the notion that outsourcing of astronaut missions to low Earth orbit is an idea whose time has come. Indeed, they have won over a seemingly unlikely convert in Mr. Augustine, who hails from the biggest of the traditional government space contractors. In an August interview, Mr. Augustine said he had been surprised by the capabilities of the commercial spaceflight industry and that he now views it as a credible option for astronaut missions. So much so, in fact, that the two options in his report that feature NASA’s currently planned space shuttle replacement system — the Orion crew capsule and its Ares 1 launcher — entail scuttling the space station by 2016, a non-starter in all likelihood.

Entrepreneurial spaceflight companies like Space Exploration Technologies (SpaceX) certainly have come a long way in the last few years. SpaceX recently carried out its first successful satellite launch aboard its Falcon 1 small rocket and is preparing its larger Falcon 9 rocket for a debut late this year or early next year. The company also is developing its Dragon cargo vessel that will launch atop the Falcon 9, and, along with Orbital Sciences Corp., is under contract to carry out commercial logistics missions to the international space station after the space shuttle retires.

But this industry still has much to prove. SpaceX, for example, is already a year behind schedule on its first Dragon demonstration flight under NASA’s Commercial Orbital Transportation Services program. Moreover, launching cargo and launching astronauts are two different things: Claims by SpaceX founder Elon Musk that a crew-carrying variant of Dragon — and of Falcon 9 — could be flying within three years of a contract award at a cost of some $20 million per seat strain credibility, especially given the difficulties the company had on the far-less ambitious Falcon 1 program.

Of course, commercial in this context isn’t necessarily limited to startups like SpaceX. For example, Boeing and Lockheed Martin, whose space businesses live on traditional government contracts, could offer crew capsules launched atop Evolved Expendable Launch Vehicle rockets, which have a solid track record in unmanned missions but have yet to be qualified to carry astronauts. Lockheed, as prime contractor on Orion, could offer a stripped-down version of that vehicle launched atop an Atlas 5 or Delta 4.

But as Mr. Augustine noted in the interview, the large aerospace primes, while clearly capable of doing the job, tend to be “bureaucratic and process bound,” whereas entrepreneurial firms might not have that handicap. In other words, the Boeings and Lockheed Martins of the world might not offer the cost and time advantages of smaller startups like SpaceX.

Either way, as the summary report notes, outsourcing crew transportation services to and from low Earth orbit is not without risk. What the document doesn’t say, but history shows, is that commercial spaceflight ventures have a very low success rate, and the few privately developed vehicles that do make it into space invariably end up costing far more than originally projected.

Mr. Augustine and his colleagues have performed a valuable service. Most notably they have debunked as fantasy the notion that NASA can have a meaningful human space exploration program — no matter what approach it chooses — in the absence of a healthy increase over the administration’s current five-year budget projections. The report also has laid out some interesting exploration alternatives — again, feasible only with a funding increase — involving destinations other than the Moon.

What isn’t clear from the summary is how astronauts would actually get to these destinations, however: on one hand, the report says outsourcing low Earth orbit missions would allow NASA to pursue a deep space vehicle “based on the continued development of the current or modified Orion”; on the other, it expressed concern about Orion’s recurring costs but also said scaling down the vehicle would be an expensive proposition.

Among the questions Obama administration officials should ask members of the Augustine panel is precisely where Orion fits — in terms of budget and schedule — in the deep-space exploration options outlined in the summary report. Perhaps this will be spelled out more clearly when the panel submits its final, more-detailed report in the days ahead.

Of themselves, administration officials need to ask two more-fundamental questions: how important is it for the United States to have an independent human spaceflight capability; and to what extent are they willing to bet the future of this capability on an industry that, while dynamic, has never taken on anything nearly so demanding.