Decisions by Presidents George W. Bush and Barack Obama to retire NASA's space shuttle and cancel the Constellation program were both received with much—and varied—emotion among my fellow astronauts, the NASA family and others nationwide. Regardless of those sentiments, these choices have brushed in broad strokes the landscape on which our future as a spacefaring nation must be painted. That backdrop reveals a stark reality: As of Atlantis's final flight last July, our nation has no means to launch humans into Earth orbit from U.S. soil. Period.

Whether considered from a geopolitical, economic or technological perspective, recovering that capability should be a national strategic priority. NASA's Commercial Crew Program (CCP) represents the fastest and most cost-effective path to that end.

That program and its cargo-carrying precursor, called COTS, for Commercial Orbital Transportation Services, are NASA initiatives to reduce costs and invigorate the American space industry. To do that, they use competitive, fixed-priced, milestone-based agreements to develop spacecraft and launch vehicle systems, rather than the traditional cost-plus-fee structure. This effort should be lauded. A recent government study using the NASA-Air Force Cost Model concluded that design, development, test and evaluation of SpaceX's Falcon 9 rocket would cost about $925 million (in fiscal 2010 dollars) under the conventional approach, compared to just $300 million under a firm, fixed-price contract.

Whence all the savings? Stable design requirements, leaner management and less government oversight all contribute. This last factor has made some wonder aloud whether this could mean a decrease in safety. Specifically, they cite NASA's perceived inability to include safety requirements in Space Act agreements, the contract vehicle used for the first three phases of the CCP.

In fact, NASA did write such specifications into Space Act agreements under COTS. More significantly, last year NASA published standards by which commercial crew competitors will be judged, regardless of acquisition strategy. NASA will not select a system that does not meet its safety requirements, and each of the competing teams is keenly aware that the degree to which they meet them will directly affect whether they win NASA's business. Furthermore, some of NASA's best and brightest—former astronauts and mission-operations and launch personnel—have joined these companies in program management and safety roles. My former colleagues are among the nation's premier space operators. Safety is their highest priority, and I would trust my life to them now, just as I did before.

A different and somewhat contradictory criticism was revealed at recent congressional hearings. This time, the complaint was that SpaceX and Orbital Sciences' upcoming COTS launches are well behind their original schedules. History is littered with examples of complex systems that were late, including every first launch of a manned vehicle by NASA and almost every major weapon system. That's just a fact. But there is a big difference under COTS: The providers must bear the costs of delays, because NASA's contribution is fixed. In fact, the government can even save money by recovering performance penalties.

When industry does launch COTS flights, it should hope for the best but be ready for less. The SpaceX mission will be an aggressive combination of two planned test flights, with a long list of objectives. Accomplishing all would be a home run, but a base hit is still a success. Like in any test flight, SpaceX will be wringing out its systems, to ferret out potential problems.

What is more, COTS and the commercial crew effort are better structured to absorb technical glitches than traditional, single-string procurements. With multiple competitors in each program, no system design or approach is exactly duplicated. Redundancy, specifically dissimilar redundancy, is a hallmark of safety and reliability. NASA has appropriately resisted recent attempts to mandate a premature down-selection in the “integrated capability” phase of the Commercial Crew Program. Its evaluation team, from rocket scientists to financial analysts, is uniquely positioned to assess the recently received proposals and make selections to ensure program success given the budgetary framework.

That framework—the level of NASA funding for CCP—will directly affect the speed with which we restore U.S. independent human access to Earth orbit. This capability is not only a national strategic imperative. It is crucial to protecting our $100 billion investment in the International Space Station. The commercial program meets this objective sooner than any other approach, cost-effectively while keeping safety paramount. Congress should join the administration in leaning forward to ensure the U.S. preserves its human-spaceflight leadership.