As they delve into the Pentagon’s 2009 budget request in the coming weeks and months, the relevant congressional committees should take a close look at the U.S. Air Force’s Evolved Expendable Launch Vehicle (EELV) program, whose costs seem to be, well, skyrocketing.

Not only does planned spending on the program rise substantially over the next several years; the projections are being revised upward. In its 2009 budget request, for example, the Air Force said it envisions spending some $6.58 billion on the program from 2009 through 2013 — about $725 million more than the service was projecting at this time last year.

The Air Force says the higher estimate is due in part to the addition of three new launches to the EELV manifest: a third Advanced Extremely High Frequency satellite and a pair of classified satellites. Fair enough, but the U.S. National Reconnaissance Office (NRO), which owns most of the classified satellites in the U.S. fleet, maintains a separate account for EELV launches, which means the program’s cost has climbed even higher than the Air Force numbers indicate.

EELV prime contractor United Launch Alliance (ULA), for its part, has attributed the rising budget curve to large block buys of Atlas 5 and Delta 4 rockets that were made in past years but whose bills will come due in the years immediately ahead.

Two recent EELV contracts have shed a bit more light on matters. In late January, the Air Force awarded ULA — technically, the contracts were signed with ULA parent companies Boeing and Lockheed Martin — $505 million for three Delta 4 launches, two of the vehicle’s heavy-lift variant. That’s not an out-of-this-world number; in fact, compared to what the Air Force was paying for launches aboard its previous heavy-lift vehicle, the Titan 4, it looks downright attractive.

But that’s only part of the story. Those contracts covered only the marginal costs of the three launches — in other words, the hardware, goods and services directly associated with the missions. EELV program overhead, the cost of maintaining two rocket production lines and associated infrastructure regardless of whether there are any launches, is paid for separately under the so-called Launch Capability contract. On Feb. 12, the Air Force announced it has extended the Boeing and Lockheed Martin EELV Launch Capability contracts by four months — at a combined cost of about $500 million. The total value of the sustainment contracts, which now cover the 10-month period from October 2007 through July of this year, is $1 billion.

There might well be a perfectly reasonable explanation for this, but $500 million for four months — which translates to $1.5 billion over a year — is a lot of money, especially when you consider that the development phase of the EELV program has long since passed. And again, this figure doesn’t even include the marginal costs of actually launching satellites. Congress should be curious as to why a 10-month EELV sustainment contract consumes virtually the entire unclassified portion of the program’s budget for 2008. The fact that the NRO contributes funding separately might explain how there could be enough money left over for actual launch services, but that’s not necessarily the point: The point is that based on the publicly available information, it appears as though U.S. taxpayers are paying more for launch services then they were a decade ago.

When the EELV program was hatched during the 1990s, the idea was to cut the U.S. government’s satellite launching bill by 25 to 50 percent. Obviously too much has changed since then to hold the Air Force to that ambitious goal. But the service does have an obligation to clearly explain why the numbers have climbed to where they are today — and whether they can be expected to come down anytime soon.

It is U.S. policy to maintain two lines of comparable launch vehicles with enough distinct components such that one can keep flying even if the other is grounded. This is perfectly rational given the critical role satellites play in military operations and intelligence gathering. But there has to be a cost threshold above which it makes sense to explore different means of assuring that U.S. national security and scientific satellites can be launched in a timely fashion.

2010, the year when the U.S. national space launch policy calls for a revisit of the so-called assured access strategy, isn’t that far off. Now is a good time to begin gathering information that includes a full accounting of EELV program costs, how the money is being spent, and the prospects that these costs will come down once the Atlas 5 and Delta 4 production facilities are more fully consolidated. This information is needed if the nation hopes to chart a course in space transportation that is sustainable over the long haul. One has to wonder whether that is the case for the current program.