Prototype Missile Defense Satellites Primed for Test Flight
An artist's illustration of the new STSS missile defense demonstration satellites in orbit.
Credit: Northrop Grumman.

WASHINGTON - The second of a pair of long-delayed missile tracking satellites is packed up awaiting orders from the U.S. Missile Defense Agency (MDA) to ship out for launch later this year, according their Northrop Grumman builders.

The first of the two Space Tracking and Surveillance System (STSS) demonstration satellites has already been shipped to a to a payload processing facility near their Florida launch said, said Gabe Watson, Northrop Grumman's STSS program manager, in a recent interview. The satellites were slated to lift off in August, but the flight is expected to be pushed back in light of a space shuttle launch delay that has muddled the manifest at their spaceport in Cape Canaveral Air Force Station, Fla. 

When they finally blast off, the STSS satellites will be launched in a stacked configuration aboard a United Launch Alliance Delta 2 rocket. The MDA in May launched a classified STSS demonstration satellite that was also built by Northrop Grumman.

Rocky road to launch pad

The STSS satellites are designed to demonstrate the ability to track ballistic missiles in every stage of flight, something current U.S. space-based assets cannot do. Northrop Grumman had originally built the satellites under an experiment dubbed the Flight Demonstration System that was canceled in 1999. The program was given a new lease on life in 2002 when the MDA awarded Northrop Grumman an $868 million contract to prepare the satellites for launch. The total amount spent on the program since 2002 has been $1.35 billion, and the MDA has requested another $180 million next year to conduct testing activities, according to figures provided by agency spokesperson Debra Christman. 

MDA's director, Army Lt. Gen. Patrick O'Reilly, criticized the STSS program on May 21 in testimony before a House Armed Services subcommittee, saying technical issues with the program were responsible for more than half of the agency's $152 million budget overrun in 2008.

"I am concerned with lapses in quality management involving several of our industry partners that have impacted system element cost, schedule and performance," O'Reilly said. "There have been frequent schedule slips on the STSS program, some resulting in significant delays, due to quality issues caused by lack of discipline and detail in the procedures."

In an interview, Air Force Col. Jay Morgan, MDA's STSS program director, defended Northrop Grumman's performance, saying it "has been typical of first-article test development and commensurate with other Space and Missile Systems Center programs and contractors, maybe better."

Watson and Morgan declined to elaborate on the specific technical issues that were encountered during development.

"Those problems are largely behind us," Watson said. "We had successful acoustic testing in August in the stacked configuration, so we've aggressively worked those issues and are moving toward a launch this year. It would be difficult for me to go down that list of items. When these are on orbit, our projections are that all technical parameters will be satisfied."

Spotting missiles from space

Following a post-launch checkout phase expected to last three months, Northrop Grumman will operate the satellites from Schriever Air Force Base, Colo., through a six-month period of testing, in which at least two dedicated ballistic missile targets will be launched to test STSS. The satellites also will participate in at least two other tests of MDA systems such as the Aegis Ballistic Missile Defense system, Morgan said. The final test program is still in flux as the agency's overall test program is not yet set.

The satellites have a staring sensor similar to that on the Air Force's Defense Support Program and Space Based Infrared System satellites, but they also have a multiband infrared tracking sensor other missile warning satellites lack, Watson said.

"Even though the hardware was built in the 1990s, when the two STSS demonstrators are on orbit, they will bring a unique capability to the MDA," Watson said. "We can track missiles in every stage of flight, from launch to intercept, and do hit assessment as well. If the MDA wants to intercept missiles in the ascent phase, they will need additional data that [current missile warning satellites] don't provide."

Congress has repeatedly turned down MDA requests for funding to begin work on an operational version of the constellation, wanting to see the results from the demonstration satellites first. As such, the agency did not request funding to begin that work in 2010. MDA Executive Director David Altwegg said in May the agency plans to request funds for 2011 if the demonstration satellites prove their mettle.

The proposed follow-on system, dubbed the Precision Tracking and Surveillance System, is in the early phases of conception, Morgan said. Decisions on that program will be largely informed by the STSS demonstration's performance. While MDA has not ruled out making a sole-source contract award to Northrop Grumman for a follow-on system, the agency is likely to hold a competition, Morgan said.

Northrop Grumman's experience building STSS would be an advantage in a potential competition to build an operational missile tracking constellation, despite considerations of past performance, Watson said.

"The expertise and experience that we've gained over the past years here I believe would position us well to compete for a follow-on, if needed," he said.