Tuesday, March 16, 2010

NAVSTAR

IOC: 1978
Total Production: 84
Total Program's Cost: USD$7.6 billion

GPS Block IIR

IOC: 1996
Production: 21

Also Known As
GPS IIR-M (Series of eight improved satellites)

Origin
United States of America

Contractor/s
Lockheed Martin

Family Members
GPS Block I
GPS Block II
GPS Block IIF
GPS Block III

Description: The GPS satellites developed under the NAVSTAR program allows any properly equipped user to determine precise time, velocity and worldwide latitude, longitude and altitude to within a few meters. Originally was designed to be an accurate guidance and navigation tool for the military services but it has been adopted by civil and commercial customers for transportation, surveying and rescue operations.

The first GPS Block I spacecraft was put into orbit on February 22, 1978. In the past, the GPS constellation spacecrafts fluctuated from 2-18 to 21 but currently the GPS constellation owned by the United States Air Force consists of 27 satellites (24+3 spares). As of 2004, the US Air Force GPS constellation consists of six planes, each one containing at least four satellites operating 24/7. Redundant satellites are being launched as spares to counterbalance attrition.

The GPS Block IIR is an improved version of GPS Block II spacecraft with an automated operation mode independent of the ground control segment. The spherical error probable was cut to 7 meters, the satellite features re-programmable micro-processors and civil/commercial signal was added. Lockheed-Martin Block IIR satellites were launched beginning in 1996 and continuing through 2004.

On June 23, 2004, the US Air Force launched successfully the GPS IIR-12 spacecraft aboard a Delta II launch system joining a constellation of 28 operational GPS satellites. GPS IIR-12 is the 11th GPS IIR satellite put into orbit successfully. GPS IIR-13 was put into orbit November 6 2004 totaling 30 satellites on orbit.

Lockheed-Martin is developing the GPS IIR-M upgrade that will incorporate two new military signals for enhanced accuracy and a second civil signal on a different frequency to eight existing GPS IIR spacecraft already built and held in storage. In addition, the modernized series will offer a modernized antenna panel that provides increased signal power to receivers on the ground, enhanced encryption and anti-jamming capabilities for the military.

The first upgraded GPS IIR spacecraft, designated GPS IIR-M1 or GPS IIR-14 (M), was launched by a Delta II rocket on 25 September 2005 at Cape Canaveral Air Force Station, Florida. Lockheed Martin and the US Air Force cleared the GPS IIR-14 (M) delivering civilian and military signals for operational use on December 19, 2005. The GPS IIR-15(M) was launched successfully by a Delta II rocket on 25 September 2006 from Cape Canaveral Air Force Station, Florida.

Specifications
Dimensions: Height 1,900 mm, Length 1,930 mm, Width 1.5 m

Weights: Max Weight 1,075 kg (2,370 lb)

Performance: CEP 7 m (23 ft), Orbit 20,200 km (10,907 nm), Service Life 10 yr

News
Raytheon to Develop Next-Generation GPS Control Segment

GPS IIR-19M Satellite Begins Operations

US Air Force 6th Modernized GPS Satellite Successfully Launched from Cape Canaveral

Boeing GPS Ground Control System Keeps Navigation Satellites Operational

Delta II Rocket with GPS Block IIR-M Payload Successfully Launches

Raytheon to Design Next GPS Control Segment for Precision Navigation and Timing

GPS IIR-17M Spacecraft Declared Operational

US Air Force Launches Fourth GPS Block IIR-M Satellite

First GPS Block IIR Satellite Marks 10 Years in Service

Lockheed Martin Delivers Eighth and Final GPS IIR-M Spacecraft

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Operators

United States of America / 21