You would think the U.S. Missile Defense Agency (MDA), having spent upward of $1 billion to refurbish and launch a pair of missile-tracking demonstration satellites left over from a canceled program, would have big plans for the craft once they were safely in orbit. But you’d be wrong.

In fact, the MDA is still revising its plan for the Space Tracking and Surveillance System (STSS) satellites more than five months after their September launch — this after numerous delays due to difficulties with both the spacecraft and their Delta 2 launcher.

The STSS satellites, built by Northrop Grumman Corp. with sensors supplied by Raytheon Co., are designed to track missiles as they coast through space during the midcourse phase of flight. The demonstration is intended to prove the viability of a constellation of satellites capable of cuing missile defense interceptors and radars with greater precision than current terrestrial and space-based systems.

The STSS satellites have taken longer than expected to get checked out on orbit due to a software issue, but the MDA doesn’t seem to be in any great hurry to find out what the spacecraft can do. As of late January, the agency said it had no specific timeline to begin the demonstration.

Worse, it’s far from clear at this point what the test program will entail. Last May, the MDA submitted a 2010 budget request that included funds for two target missile launches dedicated to the STSS demo, and the satellites also were to observe at least two other tests of other agency systems. But shortly thereafter, MDA completed an Integrated Master Test Plan that eliminated the dedicated tests.

MDA officials have pointed a finger at Congress, which trimmed $139 million from the agency’s $966.7 million budget request for tests and targets in 2010, citing what lawmakers characterized as a “premature request.” In addition, the 2010 Defense Appropriations Act specifically axed one test, FTS-01, that was to involve the STSS satellites.

But blaming Congress ignores the fact that the MDA, by its own admission, eliminated the two dedicated tests well before Congress weighed in. Work on the defense spending bill wasn’t completed until last fall; the measure was signed into law in December.

But that hardly gets Congress off the hook. These same lawmakers denied the MDA’s request for 2009 funding to design an operational missile-tracking satellite constellation, citing the lack of STSS demonstration results needed to inform such work. That’s valid reasoning, but the logic falls apart if Congress — which year in and year out approved funds for the STSS satellites — then turns around and guts the budget for the actual demonstration.

These shenanigans only reinforce long-standing concerns over the justification for investing in the STSS demonstration, in large part because of the age of the technology involved. The satellites and sensors were originally designed in the early to mid-1990s under the Flight Demonstration System program; construction was just about finished when the program was canceled in 1999 due to large cost overruns and technical difficulties. The shelved hardware got new life in 2002 when the MDA awarded Northrop Grumman an $868 million contract to refurbish it for a 2007 launch.

The demonstration’s actual cost since 2002 is probably closer to $1.5 billion judging from annual spending rates on the program. Meanwhile, the U.S. Government Accountability Office in 2003 questioned the logic of investing in technologies that in some cases would reach obsolescence before they reached orbit.

The MDA nonetheless forged ahead with the full complicity of Congress, but now that the satellites are finally in orbit, neither seems terribly concerned about getting anything out of them. Last year, Senate appropriators put the cost of two dedicated launches for STSS testing at $37 million, a marginal sum compared with the full investment in the program.

If the MDA and Congress have simply decided that dedicated tests are unnecessary, it raises the question of why they were planned in the first place. And if, as Senate appropriators argued, the STSS demo hardware bears little resemblance to the MDA’s proposed operational system, one must wonder why the program continued to get funded at an average annual rate of between $200 million and $300 million given that the Government Accountability Office made the same point almost seven years ago.

Unfortunately, little about the STSS demonstration program has made much sense in recent years; about the only thing that has added up is its cost. This hardly inspires confidence that the $67 million the MDA has requested next year for design work on an operational missile-tracking constellation will be put to better use.