— Even as the first two sensors in the U.S. Air Force’s new missile warning system perform well on orbit, where they are hosted aboard a classified spacecraft, software issues continue to dog the long-troubled program and threaten to further delay the launch of the first dedicated satellite.

A new report by the U.S. Government Accountability Office (GAO) says the Air Force has only a 50 percent chance of meeting its launch schedule for the first geosynchronous-orbiting Space Based Infrared System (SBIRS) satellite. According the congressional watchdog agency, that launch currently is slated for December 2009.

The Sept. 30 GAO report, “DoD’s Goals for Resolving Space Based Infrared System Software Problems Are Ambitious,” said the aggressive schedule for developing new software to fix the problems leaves little room for error. The Defense Department has introduced risk to the program by requesting and receiving waivers to skip “important software development processes,” the report said.

The software issue, the latest in a long line of problems that have led to lengthy delays and skyrocketing costs on the SBIRS program, was brought to light in a September 2007 memo written by Mike Wynne, who at the time was Air Force secretary. The memo said the SBIRS satellites have a design similarity to an unidentified government satellite that failed due to a faulty safe-hold mechanism. Safe hold refers to measures a satellite takes automatically to protect itself from further damage when something goes wrong on orbit. The memo also pointed to a problem with the “timing loop” on the SBIRS computer architecture.

SBIRS prime contractor, Lockheed Martin Space Systems Co. of Sunnyvale, , had anticipated delivering two new blocks of software intended to fix the problems by the end of August. The first block has been delivered. Lockheed Martin spokesman Steve Tatum said via e- mail Oct. 1 that the second block has taken longer than expected and will not be completed until November.

An interim version of the software will be delivered in time for an integrated system test before the end of October, and the final version will be delivered prior to thermal vacuum testing of the first dedicated SBIRS satellite, Tatum said.

In a written response to questions Oct. 2 about the GAO report’s warning of another delay, Tatum said the company continues to “work closely with the Air Force to support the projected [fiscal year 2010] launch readiness date.” He declined to be more specific about the launch date.

The GAO warned that if the software does not fix the problems, or if more problems occur during testing and integration, the result could be another $400 million per year in cost growth on SBIRS, whose price tag is now more than $10 billion. The GAO recommended that the Defense Department revise its cost and schedule estimates to increase confidence in success, and require Lockheed Martin to adhere to disciplined software practices to reduce risk.

In its written response, the Defense Department partially agreed with the recommendation to revise cost and schedule estimates, saying the current plan is aggressive but achievable. It concurred with the recommendation to require Lockheed Martin to adhere to disciplined software practices.

Gary Payton, deputy undersecretary of the Air Force for space programs, said Sept. 25 the SBIRS program is doing much better than in years past, but acknowledged the software problems are serious. Speaking with the media during an event here hosted by the Space Foundation, Payton did not place all of the blame on Lockheed Martin, saying some of the safeguards that could have prevented this type of problem were removed as a result of a 2005 program restructuring.

“I would say we’ve still got problems with SBIRS,” Payton said. “So finding problems with a program is never good, but I’d rather find it on the ground than in space. The [safe hold], that’s a big one. But the program, setting that aside, has been doing much better. But I can’t set that aside, the software question.

“But we are doing a much better job of meeting milestones and keeping costs under control and discovering all the problems prior to launch.”

Meanwhile, the first SBIRS payload, which is hosted aboard a classified satellite in a highly elliptical orbit, now is delivering “outstanding” operational data to the military, Col. Roger Teague, the Air Force’s SBIRS wing commander, said in a Sept. 10 interview.

While the legacy Defense Support Program constellation was designed only for missile warning, the SBIRS data now is satisfying that function as well as battlespace characterization and technical intelligence functions, Teague said.

The second highly elliptical orbiting payload is also on orbit and performing well, he said. That sensor is undergoing check-out and will be declared operational early next year.

“Their performance meets or exceeds all of our specifications, and they’re delivering outstanding results to our operational users,” Teague said.

In spite of the ongoing software issue, confidence in the SBIRS program has grown to the point that it looks as though the Air Force will wind up buying at least five SBIRS satellites as originally planned. Lockheed Martin’s original SBIRS contract called for the company to deliver five dedicated geosynchronous satellites, with one to serve as a ground spare, and two sensors to be hosted by classified satellites. But the number of dedicated satellites was pared to as few as two satellites, and no more than three, in the 2005 restructuring, which was ordered to curb runaway cost growth on the program.

The Pentagon last year approved the procurement of a third geosynchronous satellite and two more highly elliptical payloads, and in September it approved a fourth geosynchronous satellite.

The 2009 defense appropriations bill signed into law Sept. 30, funds SBIRS at $2.2 billion next year, and language in the accompanying report directs the Pentagon to include funds to buy a fifth satellite in its 2010 budget request. Lockheed Martin currently is under contract for two geosynchronous satellites and long-lead items for a third.

“Procurement of this geosynchronous fourth satellite will complete the SBIRS constellation that was originally envisioned,” Teague said. “This was again more good news for the mission area. It validates a lot of the great work and really assures our posture going forward.”

Jeff Smith, Lockheed Martin’s SBIRS vice president and program manager, said in a Sept. 10 interview that the first SBIRS satellite was slated to undergo acoustic testing in October. The second satellite’s core structure and propulsion subsystems have been integrated, and testing of the payload now is being performed in , by payload subcontractor Northrop Grumman Electronic Systems.