Los Angeles Air Force Base   Right Corner Banner
Join the Air Force



Posted 6/3/2014 Printable Fact Sheet
Download HiRes


Deliver sustained, reliable GPS capabilities to America's warfighters, our allies and civil users. GPS provides positioning, navigation and timing service to civil and military users worldwide.


In 1989, the GPS IIR contract was awarded to Lockheed Martin for the development and production of 21 space vehicles (SVs). In August, 2000, the United States Air Force awarded Lockheed Martin a contract to modernize eight existing GPS IIR satellites. On 17 August 2009, the last GPS IIR-M (modernized) satellite was launched from Cape Canaveral AFS, Fla.


The GPS IIR/IIR-M program has entered into the sustainment phase with closeout of the original GPS IIR contract pending.

· Current contract: Sustainment
o Monitor GPS IIR satellites from Schriever AFB
o Support 2 SOPS in day-to-day control and maintenance
o Provide trending analysis
o Provide expertise in resolving anomalies/out-of-family conditions

· Production Contract: Closeout Contract Line Numbers (CLINs)
o Disposition of all GPS IIR/IIR-M material
o Verify and close remaining CLINs
o Continue to execute the on-orbit incentive plan
o Final contract actions

· Legacy signals: L1 C/A, L1/2 P(Y)
· Modernized signals: L2C (GPS IIR-M only), L1/2 M-Code (GPS IIR-M only)
· Navigation Message
· Orbit: Six orbit planes at 55 degree inclination
· Altitude: 10,898 nautical miles
· Design life: 7.5 years, 6-years MMD
· On-orbit weight: 2484 lb
· Size: 62 in wide, 77 in deep, 87 in high
· Position accuracy: 3 meters, with daily updates from the control segment

Electrical Power Subsystem
· Solar array: 144 ft2; high-efficiency silicon cells, 1040-watt capacity
· Battery system: NiH2, rechargeable
· Electronics: Central controller with redundant discharge converters and battery chargers

Attitude Determination and Control
· Design approach: Zero momentum, 3-axis stabilized, Earth-oriented, Sun-nadir pointing
· Attitude reference control: Static Earth sensor, Sun sensor, reaction wheels/magnetic coils

Propulsion Subsystem
· Design approach: Monopropellant N2H4
· Propellant capacity: 208 lbs
· Thrusters: Twelve 0.2-lb REAs and four 5.0-lb REAs

Total Navigation Payload
· Timekeeping subsystem: Multiple atomic frequency standards: Rubidium clocks, radiation-hardened design, high stability timing, automated integrity monitoring
· Mission Data Unit: 1750A central processor, ADA HOL, integral baseband processor, full message encoding and processing, real-time Kalman filter
· Crosslink transponder data: RF receive and transmit, precision inter-satellite ranging, full-frame modulation and mode control

Structure and Thermal
· Modular design: Six aluminum honeycomb panels mounted to a central aluminum core
· Passive thermal control: Blankets, thermal coatings, radiators, and electrically controlled heaters, new L-band panel with heat pipes for GPS IIR-M SVs
· Active thermal control: Electrically controlled heaters, relays, thermostats

Tracking, Telemetry, and Command
· RF links: Two S-band transponder using SGLS channel 6
· Security architecture: Encrypted data links, redundant 1750A control processor, centralized command decoding and telemetry communications
· Autonomy: On-board power and key component redundancy management

Prime Contractor:
Lockheed Martin

(Current as of March 2014)

 Inside LA AFB

ima cornerSearch

ima cornerSatellite Systems


tabJoin the Conversation!
Los Angeles AFB Facebook page  Los Angeles AFB Twitter account  Los Angeles YouTube page
tabFrequently used links
Be part of something BIG! Launch your career at the Schriever Space Complex with Space and Missile Systems Center at Los Angeles Air Force Base in El Segundo, Calif. For details, click this link.
Fort MacArthur Inn (Air Force Inns)
Airman & Family Readiness services at Los Angeles AFB
Los Angeles AFB Child Development Center
Click this button to donate to the Combined Federal Campaign of Greater Southern California
Los Angeles AFB Commissary
Exceptional Family Member Program
Army & Air Force Exchange Service
61st Force Support Squadron
Federal Voting Assistance Program
Los Angeles AFB Fitness Centers
General information about Los Angeles Air Force Base
Los Angeles AFB Medical Clinic (61st Medical Squadron)
Hometown News Release Online
ID Card Appointments
SMC Key Spouse program
Newcomer Information
Los Angeles Air Force Base Retiree Activities Office
Los Angeles AFB RideShare & Parking program office
Sexual Assault Prevention and Response (SAPR) program
Single Airmen Program
Tax Center
SMC Base Housing (Tierra Vista at Ft. MacArthur, San Pedro, Calif.)

Site Map      Contact Us     Questions     USA.gov     Security and Privacy notice     E-publishing  
Suicide Prevention    SAPR   IG   EEO   Accessibility/Section 508   No FEAR Act