The dearth of U.S. government funding for space-related research and development has manifested itself yet again in U.S. Air Force’s decision to discontinue competitive design work on a prototype reusable rocket dubbed Pathfinder. The project was aimed at demonstrating a reusable first stage that returns to its launch site after completing its portion of a satellite-launching mission.

The Air Force budgeted $250 million for the Pathfinder project and last December awarded yearlong study contracts worth about $2 million apiece to Andrews Space, Boeing and Lockheed Martin. The service now says it will not award further Pathfinder task orders as previously planned due to “unexpected funding reductions.”

The only surprising thing about that development was the service’s use of the term “unexpected,” which these days would be more appropriate when funding for projects like Pathfinder survives the Pentagon’s internal budget deliberations. The Air Force’s Oct. 24 announcement that it would fly its fourth experimental X-51A Waverider hypersonic vehicle despite the disappointing results from the first three flights was unexpected, for example — heartening as it was.

Pathfinder was a prototype for an operational reusable booster system (RBS) that the Air Force envisioned as one day replacing its current fleet of expendable rockets to reduce the cost of launching national security satellites. In this budgetary environment, of course, the notion that the Air Force could actually afford to build such a system is pure fantasy; a recent National Research Council (NRC) report admonishing against major investments in an operational RSB is a bit like telling an anesthetized snail to obey the speed limit.

But the NRC also said the Air Force should continue investing in enabling technologies and singled out Pathfinder as an effort worthy of expansion to support development of multiple competitive prototypes. Indeed, even if a major reusable launcher development isn’t in the cards anytime soon, it makes sense to lay the technological groundwork for when that day finally comes. These kinds of efforts also have immediate benefits — keeping the nation’s aerospace engineering talent cultivated and interested.

This is not to lay blame on the Air Force for discontinuing Pathfinder — the Air Force, like the other military services, is struggling mightily in the current budget environment just to fund its operational priorities. It could be, moreover, that the service had no choice in the matter: The Pathfinder program was set up as an indefinite quantity, indefinite delivery contract arrangement, and according to one top U.S. industry official, task order awards under such contracting vehicles are barred by the continuing resolution that is keeping the U.S. federal government funded for the first half of fiscal 2013. But 30 years from now, when people lament the fact that rockets haven’t changed much since the dawn of the Space Age — this is a familiar complaint today — Pathfinder’s apparent fate will be among several examples of why that’s the case.