Responding to a Government Accountability Office report on U.S. space capabilities and related congressional testimony, the Air Force said last week that it has "plans to mitigate risk and prevent a gap" in Global Positioning System (GPS) coverage.

"No, the GPS will not go down," said Col. Dave Buckman, the Air Force Space command official for position, navigation and timing at the Peterson AFB, Co.

However, Buckman acknowledged, "GAO points out, there is potential risk associated with a degradation in GPS performance."

Buckman's comments came during a May 20 session on the command's Twitter page.

The GPS constellation currently has 31 operational satellites. The Air Force is expected to spend over $6 billion over the next five years to maintain those satellites, launch new ones and keep ground control stations operating smoothly, according to budget documents.

"The current GPS constellation has the most satellites and the greatest capability ever," the service said in a statement on Friday. "We are committed to maintaining at least our current level of service, while striving to improve service and capability through ongoing modernizaton efforts. The Air Force will continue to pursue an achievable path maintaining GPS as the premier provider of positioning, navigation and timing for the military and civilian users around the world."

The Air Force was responding to a GAO report and May 9 testimony before a panel of the U.S. House Committee on Oversight and Government Reform.

"It is uncertain whether the Air Force will be able to acquire new satellites in time to maintain current GPS service without interruption," GAO acquisition Director Christina Chaplain said at the time.

However, Buckman said two satellite programs intended to upgrade GPS capability are on track and it's "very unlikely" that users will notice any degradation in performance. He said the next satellite is expected to launch in August.

In a report released earlier this month, GAO said 24 satellites are needed to keep GPS operational for civil, commercial and military use above a 95 percent probability of maintaining "acceptable performance standards." But, citing Pentagon officials, the report adds that the probability of maintaining 24 operational satellites is expected to fall to as low as 80 percent between fiscal year 2010 and 2014.

As a result, Chaplain said, there could be a degradation in accuracy of precision-guided munitions and an increase in delays and cancellations of commercial airline flights.

Buckman, however, assured reporters that "going below 24 won't happen."

"There's only a small risk we will not continue to exceed our performance standard," he said. "Since 1995, GPS has never failed to exceed performance standards."

The GAO recommended that Defense Secretary Robert Gates appoint a single authority to oversee GPS development to ensure greater synchronicity.

Boeing, the prime contractor for the next two GPS satellites set to launch, said this next iteration of the program "will deliver more capability and improved mission performance to military and civilian users."

In a statement issued May 20, a spokesman said the company "has taken aggressive steps to resolve the technical issues" that have caused schedule slips.

"Design changes were required to ensure performance over the satellite design life and have caused schedule delays, but these changes are in the final phase of implementation and a fully integrated satellite (SV1) has already successfully completed the thermal-vacuum test program--the most stressing system level test," the statement reads. "We are on track to deliver SV1 to the Air Force later this year for the...launch."