GPS-2R [Lockheed Martin]
GPS-2R (Global Positioning System) or Navstar-2R (Navigation System using Timing And Ranging) are the third evolution stage of the second generation of the GPS satellites.
The GPS-IIR replenishment satellites are produced by General Electric Astrospace (later Martin Marietta and Lockheed Missiles & Space) under a contract issued in 1989, which included 21 satellites based on the commercial AS-4000 bus. These provided improved navigation accuracy and longer autonomous satellite operation than earlier model GPS satellites. The satellites were three-axis stabilized and operated at downlink frequencies of 1572.42 MHz and 1227.6 MHz (L-Band) and 2227.5 MHz (S-Band). Lockheed was responsible for launch and flight operations support of the GPS-IIR through 2006.
Block IIR satellites provided dramatic improvements over previous blocks. They could determine their own position by performing inter-satellite ranging with other IIR vehicles. They also had reprogramable satellite processors enabling problem fixes and upgrades in flight, increased satellite autonomy, and radiation hardness.
Additionally, the Block IIR could be launched into any of the required GPS orbits at any time, assuming a 60-day advanced notice, and required many fewer ground contacts to maintain the constellation. All of these improvements result in increased accuracy for GPS users and a cost 33 percent less per satellite than the previous generation of Block IIA satellites. Up to 12 Block IIR satellites were to be modified to use the new military M-code on both the L1 and L2 channel as well as the more robust civil signal L2C on the L2 channel. The M-code signal was to enable GPS operations in a higher jamming environment and reduce vulnerability of military GPS-based systems. The first modified Block IIR (or IIR-M) is planned for launch 2004.
|Type / Application:||Navigation|
|Power:||2 deployable solar arrays, batteries|
|Orbit:||20200 km × 20200 km, 55.0°|
|GPS-2R 1 (Navstar 42)||16.01.1997||CC LC-17A||F||Delta-7925|
|GPS-2R 2 (Navstar 43, USA 132)||23.07.1997||CC LC-17A||Delta-7925|
|GPS-2R 3 (Navstar 46, USA 145)||07.10.1999||CC SLC-17A||Delta-7925|
|GPS-2R 4 (Navstar 51, USA 150)||11.05.2000||CC SLC-17A||Delta-7925|
|GPS-2R 5 (Navstar 44, USA 151)||16.07.2000||CC SLC-17A||Delta-7925|
|GPS-2R 6 (Navstar 41, USA 154)||10.11.2000||CC SLC-17A||Delta-7925|
|GPS-2R 7 (Navstar 54, USA 156)||30.01.2001||CC SLC-17A||Delta-7925|
|GPS-2R 8 (Navstar 56, USA 166)||29.01.2003||CC SLC-17B||Delta-7925||with XSS 10|
|GPS-2R 9 (Navstar 45, USA 168)||31.03.2003||CC SLC-17A||Delta-7925|
|GPS-2R 10 (Navstar 47, USA 175)||21.12.2003||CC SLC-17A||Delta-7925|
|GPS-2R 11 (Navstar 59, USA 177)||20.03.2004||CC SLC-17B||Delta-7925|
|GPS-2R 12 (Navstar 60, USA 178)||23.06.2004||CC SLC-17B||Delta-7925|
|GPS-2R 13 (Navstar 61, USA 180)||06.11.2004||CC SLC-17B||Delta-7925|
|GPS-2R 14 (Navstar 53)||converted||→ GPS-2RM 1|
|GPS-2R 15 (Navstar 52)||converted||→ GPS-2RM 2|
|GPS-2R 16 (Navstar 58)||converted||→ GPS-2RM 3|
|GPS-2R 17 (Navstar 55)||converted||→ GPS-2RM 4|
|GPS-2R 18 (Navstar 57)||converted||→ GPS-2RM 5|
|GPS-2R 19 (Navstar 49)||converted||→ GPS-2RM 6|
|GPS-2R 20 (Navstar 48)||converted||→ GPS-2RM 7|
|GPS-2R 21 (Navstar 50)||converted||→ GPS-2RM 8|