After nearly a decade of increases, U.S. military space spending had to tail off sooner or later, and if the White House’s 2011 defense budget request is any indication, that time is at hand. A quick look at proposed spending next year across the U.S. Air Force’s major unclassified space accounts shows a decline of some $500 million, or 6 percent from current-year levels.

This comes as no surprise following last year’s cancellation of the Transformational Satellite (T-Sat) communications system — the correct call given the program’s immense complexity and $26 billion price tag — and with the Advanced Extremely High Frequency system making the transition from development to production. It is also fair to point out that much of the spending growth seen in recent years has been driven by cost overruns on critical programs, most notably the Space Based Infrared System missile warning constellation.

Still, one could be forgiven for being a bit disappointed with some aspects of U.S. President Barack Obama’s request. It would have been nice if, for example, the request had included more funding for operationally responsive space, which in the absence of any major new satellite program starts is one of the few activities that can spur innovation by keeping the competitive side of the industrial base warm.

As it is, the budget supports the continued recapitalization of the operational U.S. military satellite fleets. If there was a surprise in the request, it was the White House’s decision to end a 15-year-old partnership between the Air Force and National Oceanic and Atmospheric Administration (NOAA) to develop a civil-military weather satellite fleet. That program had major problems due both to its complexity and a management structure where no one had clear authority to make key decisions.

While it’s hard to argue with the move, especially since the Air Force and NOAA have different schedule requirements for their new-generation polar-orbiting weather satellites, it’s hard to see how it will save money. NOAA’s proposed 2011 budget for its new program is more than $1 billion, which dwarfs the agency’s 2010 budget for the now-canceled program. The Air Force request for its go-it-alone system, at $352 million, is less than $40 million shy of its 2010 budget for the joint program; how that money will be spent is anybody’s guess at this point.

The inevitable down cycles in space spending are painful, but it is worth noting that money isn’t always well spent during times of plenty. The Air Force during the past decade spent billions of dollars between T-Sat and the Space Radar, two so-called transformational programs that were too technologically ambitious and beyond the service’s means — even in the days of soaring defense budgets. It remains to be seen whether the Air Force and industry will be able to utilize whatever new technology was developed under those now-defunct programs.

If there is an upside to the coming scarcity, it is that the Air Force will have to be more creative to get new capabilities deployed. That means taking advantage of opportunities, which often entails leveraging the capabilities of the commercial sector. One promising avenue is paying commercial satellite operators to host dedicated military |payloads.

In that regard, the Air Force was correct to continue an effort to place an experimental missile warning sensor aboard a commercial telecommunications satellite — even as the service scaled back the wider Third Generation Infrared Surveillance technology program. That hosted-payload arrangement is a pathfinder, in part because it entails placing highly sensitive technology aboard a satellite to be launched atop a non-U.S. rocket, a European Ariane 5. Also encouraging was a request for information from commercial satellite operators issued last year by Air Force Space and Missile Systems Center — as traditional a procurement shop as there is — in the wake of T-Sat’s cancellation.

Another tool at the Air Force’s disposal is small, low-cost spacecraft that can be launched on relatively short notice to fill in gaps in the service’s operational capabilities.

But these alternative ways of acquiring capability, while relatively inexpensive, still cost money, and it is not clear where that money will come from. A logical source of funding is the Operationally Responsive Space (ORS) Office, both for small dedicated spacecraft and for hosted-payload arrangements. But the administration’s budget request for that office appears sufficient only for projects already in the works, in particular a reconnaissance satellite needed to serve an urgent yet unspecified Pentagon need.

Obviously the Air Force cannot set aside funding for every possible contingency, but the ORS Office’s founding purpose is to respond quickly to meet new requirements or plug gaps in the existing space architecture as they are identified. That requires a funding pool that isn’t necessarily tied to existing projects.

Congress should scrutinize the Air Force’s budget request with an eye toward shifting money to the ORS Office. Among the space accounts, one place to look is the service’s request for weather satellites, which at $352 million is awfully large for an undefined program. It might make sense to steer a portion of that money to the ORS Office, which could set it aside as a reserve, to be tapped only when a specific need is identified.