The U.S. Defense Department continues to ignore prudent technology-development procedures by placing bets on unproven systems, a practice that too often leads to sharply higher program costs, reduced buying power or both, the U.S. Government Accountability Office (GAO) says in a report.

The report, “Defense Acquisitions: Assessments of Selected Major Weapon Programs,” evaluates 52 big-ticket U.S. military systems. It compares their latest cost estimates, delivery dates and procurement quantities with previous estimates.

The report, dated March 31, concludes that too many programs, including several major space systems, are approved before the key technologies have been demonstrated.

One of the principal findings comes in the response the Defense Department gave to GAO auditors before the report was published. According to the GAO, the Defense Department said it tests technologies “in at least a relevant environment before a program enters system development.”

The GAO says a better way is to assure that key subsystems are tested in an operational environment. “The cost of proceeding without the necessary knowledge can be dramatic,” the congressional watchdog agency concludes.

Ten of the 52 systems reviewed by the GAO are satellite or launch vehicle programs. Some are too early in development to show much change in expected cost. But even in these programs, the GAO often raises warning flags that subsystems central to the programs’ performance have not been sufficiently proven.

The following are examples of programs selected for review and GAO assessments:

Space Radar: A constellation of 22 satellites is being designed to track moving or fixed targets, with a rough total cost estimate of $22.3 billion. But the GAO says none of the five critical technologies needed for Space Radar have been fully proven.

“At this point, the program is expected to enter system development before any of the technologies are mature,” the GAO says.

In its response , the U.S. Air Force says it is implementing a strict risk-reduction program, and is weighing an in-orbit demonstration satellite as well.

“In 2007, the program plans to decide whether to develop on-orbit demonstration satellites to validate technology maturity and costs,” the GAO says.

Advanced Extremely High Frequency ( EHF) satellite system : The GAO says EHF, whose first satellite launch has slipped to 2008, “still faces schedule risk due to the continued concurrent development of two critical-path items.”

Delays in the delivery of cryptographic equipment by the U.S. National Security Agency have already added $800 million to the program’s total costs, and further delays are possible both for this gear and for command-post terminals, according to the GAO.

Evolved Expendable Launch Vehicle (EELV): This program financed development of the Atlas 5 and Delta 4 vehicles, which have completed 11 successful launches combined, the GAO says.

The EELV development model, based on commercial practices at a time when the commercial launch business was booming, has collapsed with the market decline.

The Air Force, in response to the GAO, says it could not furnish specific data on technology and design status because it has not contracted with its suppliers to provide this information.

GPS 2: The GPS navigation and timing constellation features second-generation satellites under development by Lockheed Martin and Boeing Co. While research and development costs have exceeded estimates by 20.4 percent, total program costs have been in line with the increased number of GPS 2F satellites ordered.

But the report warns that the space-qualified atomic clocks required for GPS satellites, while presenting no major technology-development hurdles, may pose challenges because of the declining number of U.S. companies capable of building them.

Mobile User Objective System (MUOS): Two of the nine technologies considered critical for MUOS are not yet ready , with a critical design review scheduled for March 2007, the GAO says.

The two immature technologies are a cryptographic chip for the ground-based satellite control facilities, and a converter to transform digital signals into analog format. Certain long-lead items will be purchased before the critical design review, a risky strategy that the U.S. Navy says is necessary because of schedule demands on MUOS.

“[T]he importance of the first MUOS launch date has increased due to the unexpected failure of a UHF Follow-On satellite in June 2005,” the GAO says.

Space Based Infrared System (SBIRS) High: Program contractors have long said the missile warning system presents technical challenges that have proved more difficult than predicted. In responding to the GAO report, the Air Force echoed that opinion, saying “the program suffered from a lack of military specifications with proper quality controls.”

With the program under fire in the U.S. Congress, the Air Force is expected to begin designs of a replacement system, with an initial plan to be presented in April , GAO said .

Wideband Gapfiller Satellites : The first satellite has been reworked, and two others inspected, following the discovery in 2005 that 148 fasteners had been improperly installed. There are more than 1,500 fasteners on each satellite.

A first launch is now scheduled for mid-2007, and Boeing has been obliged to finance the fastener-related inspections. In response to the GAO, the Wideband Gapfiller program office says that “the government and contractor are instituting increased levels of oversight on the supplier’s quality management program to avoid these types of problems on future satellites,” according to the GAO.