The Air Force has delayed the launch for its first Global Positioning System (GPS) III satellite and further delayed navigation payload delivery due to continued payload development challenges.
Air Force Space Command (AFSPC) spokeswoman Capt. Connie Dillon told Defense Daily in an email the navigation payload issues encountered by prime contractor Lockheed Martin [LMT] and subcontractor Exelis [XLS] have pushed payload delivery back until this summer. Lockheed Martin said in January it expected navigation payload delivery in “early” 2014. Exelis, developer of the navigation payload, said in September delivery was originally scheduled for late 2013.
Dillon said the navigation payload delivery delay does not allow sufficient time for the program to meet the current launch date, which launch provider United Launch Alliance (ULA) said in January was originally contracted for fourth quarter 2015 (Defense Daily, Jan. 10). ULA deferred requests for comment to the Air Force. ULA is a joint venture of Lockheed Martin and Boeing [BA].
Signal crosstalk, or interference, seems to remain a problem for the GPS III industry team. Exelis said in September it delayed navigation payload delivery to assure there was no crosstalk within the mission data unit. Lockheed Martin spokesman Chip Eschenfelder said Monday in an email the two companies last year identified navigation payload development issues that needed further work. Eschenfelder said significant testing with flight-like engineering units and the first GPS III satellite’s flight hardware indicates that the known technical issues are being resolved. He added the payload hardware is built and currently in testing.
Lockheed Martin said it has made progress with the second GPS III satellite, GPS III-2, as it recently turned power on to the bus and network communications equipment payload, according to a company statement. Lockheed Martin said this is a major production milestone that demonstrates the satellite’s mechanical integration, validates its interfaces and leads the way for electrical and integrated hardware-software testing.
Lockheed Martin said the propulsion core for GPS III-2 was delivered to the company’s Colorado-based GPS processing facility in early November from a company facility in Mississippi where it was made. The core, which Lockheed Martin calls the structural backbone of the satellite, contains the integrated propulsion subsystem that allows the GPS III satellite to maneuver on orbit immediately after launch, as well as conduct repositioning maneuvers throughout its mission life.
Lockheed Martin is currently under contract for production of the first six GPS satellites with the first four funded under the original contract and the fifth and sixth recently fully-funded by an Air Force-exercised option on Dec. 13. Lockheed Martin had previously received advanced procurement funding for long-lead components for the fifth, sixth, seventh and eighth satellites. DoD also announced Monday the Air Force awarded Lockheed Martin $14 million for long-lead material for GPS III-7 and GPS III-8.
AFSPC chief Gen. William Shelton last September said the program was on decent footing, despite manufacturing and process issues with the navigation payload (Defense Daily, Sept. 18). Shelton’s spokeswoman did not respond Monday to a request for comment. Shelton will be in Washington Friday to speak at an Air Force Association (AFA) breakfast seminar on space.
GPS III is a next-generation Air Force positioning, navigation and timing (PNT) program that will replace aging GPS satellites in orbit, improving capability to meet the evolving demands of military, commercial and civilian users.