As it stands now, NASA will retire the remaining Space Shuttles—Discovery, Endeavour and Atlantis—sometime in 2010 in order to make way for the Orion Crew Exploration Vehicle (CEV) and a launch vehicle known as Ares I. By shutting down the Shuttle program, NASA will be able to divert precious economic, human and material resources to the CEV program. But there are problems with this plan, and Americans are only now realizing what scuttling the Shuttle could mean.

The first problem, as deputy NASA administrator Shana Dale explained earlier this year, is this: “Our best estimates still maintain an initial operational capability for the Orion and Ares I of March 2015.”

That leaves a gap of five years, during which the U.S. will have no way of delivering personnel into space on U.S. spacecraft.

How will we bridge the gap? That leads us to a second problem. The U.S. will purchase “crew and cargo services from Russia and our international partners,” in Dale’s worrisome words.

Any doubts about the dangers of this predicament were obliterated by Russia’s blitzkrieg battering of Georgia.

And that leads to a third problem with shutting down the Shuttle program before a replacement is ready: Even if Vladimir Putin didn’t act like a latter-day czar, hitching a ride with the Russians could undermine America’s international standing and national security posture.

As a consequence, some policymakers propose not retiring the Shuttle until the CEV is operational. Presidential contenders Barack Obama and John McCain have voiced support for extending Shuttle flights, although it is unclear for how long. At some $4 billion per year, according to estimates cited by the Orlando Sentinel, that prospect carries a high cost.

In August, citing Russia’s invasion of Georgia, McCain asked President Bush to “direct NASA to take no action for at least one year from now that would preclude the extended use of the Space Shuttle beyond 2010.” In September, Obama asked NASA to “take no further action that would make it more difficult or expensive to fly the Shuttle beyond 2010.”

In a word, both candidates want flexibility. The next administration got a little wiggle room at the end of September, when Congress passed a measure that pays for an extra Shuttle flight and for costs associated with delaying the planned retirement of the fleet. Congress also extended a waiver allowing NASA to buy seats for American astronauts on Russian rockets—something the U.S. space program will need after the Shuttle flies its last mission.

What few Americans realize is that Russia began carrying American crews and cargo to the International Space Station after the Columbia disaster. According to NASA administrator Michael Griffin, “NASA’s current contract with Russia is worth almost $780 million through 2011.”

Of course, collaborating with Russia by choice is far different than counting on Putin and his puppets out of necessity.

To his credit, Griffin called U.S. dependence on Russian rockets “unseemly in the extreme” long before Russia plowed into Georgia. “It is dangerous for the United States to find itself dependent upon any external entity for a strategic capability,” he warned in early 2008.

His words were prescient, as became clear during the August war in Georgia. Griffin told The International Herald Tribune that he ordered NASA to explore contingency plans for using the Shuttle beyond 2010 “about five minutes after the Russians invaded Georgia.”

New resources, like those added to NASA’s 2009 bottom line by Congressional action, may help add a Shuttle mission or two at this end and speed completion of the CEV system at the other. But because building new spaceships and retiring old ones is not like flipping a light switch, it is going to be very difficult to close the gap completely.

According to Griffin, “It is essentially unfixable now.” This is due to the transfer of personnel and resources to the post-Shuttle program, the closing out of contracts, and the conversion of systems and facilities.

All of this means that for some period of time the U.S. will either a) rely on Russian rockets to deliver American astronauts and equipment into space, or b) not send its own into space.

To be sure, the U.S. is not going to cease to be a space-faring nation during these gap years. The Pentagon will continue to be active in space. In fact, it is estimated that space programs directly related to national security receive two times the funding NASA receives.

But it pays to recall that the Shuttle has served more than scientific and civilian purposes. Many Shuttle missions have been military missions, some of them highly classified.

In addition, the Shuttle in specific—and U.S. manned space flight in general—serves as evidence of American strength and technological prominence. Thus, in a realm beyond yet related to America’s security, surrendering the ability to carry astronauts into space promises to be a blow to America’s prestige. Remember, we already live in an era when America is perceived as a nation in decline.

Investing more money in NASA may help, but it won’t make up for the bipartisan under-funding the space agency has endured since the Apollo era ended. Besides, there isn’t much more to invest. America has spent a lot these last several years—some of it necessary ($800 billion waging the war on terror), some of it questionable ($39 billion a year for Medicare Part D), some of it wasted ($2 billion in post-Katrina fraud), some of it all of the above ($700 billion bailing out bad decisions on Wall Street and Main Street).

Governing is often about choosing the least bad option. The next president will certainly understand this as he grapples with the future of America’s space program.