With its selection of Boeing and Space Exploration Technologies Corp. to develop competing capsules to transport astronauts to and from the international space station, NASA took a big step toward restoring a human spaceflight capability the United States has lacked since the 2011 retirement of the space shuttle fleet.

In announcing the awards Sept. 16, NASA Administrator Charles Bolden acknowledged the difficulty of leaving Sierra Nevada Corp. Space Systems — the only commercial crew contender to propose a vehicle that would glide to Earth for a runway landing — high and dry. 

But NASA’s acquisition professionals are paid to make the choices that make the most sense for the nation’s civil space program.

Contrast that with the U.S. Congress, whose latest failure to perform its most basic function, passing a budget, effectively ensures that NASA’s effort to end its reliance on Russia for space station crew access will start off in a fiscal hole. Lawmakers, who have shortchanged the program from the beginning — while giving generously to a giant rocket and deep-space capsule whose only identified mission they have rejected — settled yet again for a continuing resolution that funds federal activities at prior-year levels.

That means that, at least through Dec. 11, when the current measure is slated to expire, the commercial crew program will be funded based on an annual level of $696 million, which is $152 million less than the $848 million requested for 2015 by the Obama administration. It remains to be seen whether lawmakers, who have adjourned for the November elections, will get serious about passing a real budget once they return.

Even if Congress eventually passes a targeted spending bill, the commercial crew program likely would receive no more than the $805 million proposed by Senate appropriators, compared with the $785 million recommended by their counterparts in the House. A 5 percent reduction from the request might not seem like a lot, but it’s enough to slow any program. 

Given the history of space development projects, Boeing and SpaceX will be hard pressed to debut their respective vehicles in 2017 as planned even under a fully funded program.

Congressional supporters of NASA’s heavy-lift Space Launch System and Orion deep-space capsule have traditionally been skeptical of the commercial crew program and of SpaceX, which unlike Boeing has no skin in the SLS/Orion game.

But SpaceX has been answering its critics of late, most recently with its successful Sept. 21 launch of cargo to the space station, the company’s sixth mission this year and second in less than a month. Meanwhile, and in contrast with SLS and Orion, the commercial crew program has a specific, well-defined mission whose importance is not in question, even among its critics on Capitol Hill. 

In the wake of the commercial crew contract awards, Rep. Lamar Smith (R-Texas), chairman of the House Science Committee, said the program offers the best bet for ending U.S. reliance on Russia for access to the space station. He’s absolutely right, and his acknowledgment of that fact is both welcome and encouraging.

At the same time, Mr. Smith suggested he plans to keep the program under the congressional microscope. That’s perfectly appropriate, just so long as the scrutiny doesn’t tie the hands of NASA and its contractors to the point that the program loses the advantages of commercialization.

But the best thing Mr. Smith and his colleagues on both sides of the Hill — and both sides of the aisle — can do to ensure, in his words, “safe and reliable transportation to the international space station” is to fully fund the commercial crew program. That begins with passing a budget for 2015.