|
Delta
2 Launches GPS 2R-9
|
More
Information: |
|
(source: USAF) |
A Delta 2-7925
successfully launched Global Positioning Satellite (GPS) 2R-9 from
Cape Canaveral, pad 17A, at 22:09 UTC on March 31. GPS 2R-9 (SVN
45) will be deployed into the GPS constellation's Plane
D, Slot 3. It is expected to enter service within a month of
launch. The satellite will be placed in a MEO orbit at an
altitude of 20,200 km (10,900 nmi) inclined at 55 degrees. The
launch is priced at US$50 million. GPS 2R-9 will replace GPS 2-5 (SVN
17). Controllers plan to shift GPS 2-5 toward the D1 slot, making
it a "close pair" with GPS 2A-11. GPS 2-5 is over 13
years old and has been operating on three of four reaction wheels
since December 2000. A satellite requires three reaction wheels to
maintain attitude control and to perform the GPS missions. Except
for some risk associated with the three remaining reaction wheels,
GPS 2-5 is in relatively good condition. Today, the orbiting
system has 27 craft that are considered healthy.
This
is the ninth Block 2R satellite, of a block order of 21, to be
supplied by Lockheed Martin. The 2032 kg (4478 lbm) satellite
design is based on Lockheed Martin’s AS-4000 series satellite
bus, with a design life of 10 years. The Block 2R satellites offer
improvements over the previous blocks of satellites, having the
ability to determine their own position by performing
inter-satellite ranging with other 2R vehicles, adding
reprogrammable satellite processors to enable problem fixes and
upgrades in flight, and increased satellite autonomy and radiation
hardness. Block 2R spacecraft have the ability to be launched into
any of the required GPS orbits at any time with a 60-day advanced
notice and requires far fewer ground contacts to maintain the
constellation. These improvements result in increased accuracy for
GPS users with a cost reduction of 33 percent per satellite over
the previous generation of Block 2A satellites. Block 2R
satellites will replace Block 2/2A satellites as they reach the
end of their service life. Block 2R satellites cost US$42 million.
The GPS
system is separated into six orbital planes, requiring a minimum
of four satellites in each, to operate.
Table
1: GPS Satellite Planes/Slots
Click
on individual cells for more information on the satellite.
Note:
Nomenclature used in this table: Block number (2, 2A or
2R), satellite within block. In parentheses, USAF space vehicle
number of GPS satellite. GPS 2R-1 (42) was destroyed in a
Delta launch failure on January 17, 1997.
 The Global
Positioning System (GPS) network is operated by the U.S. Air Force
to provide highly accurate position, speed and timing information
to military forces around the world, and is used by a growing
number of commercial products. The NAVSTAR Global Positioning
System is managed by the NAVSTAR GPS Joint Program Office at the
Space and Missile Systems Center, Los Angeles Air Force Base,
California. The USAF
50th Space Wing located at Falcon Air Force Base, Colorado,
operates and controls the system.
NAVSTAR
GPS stands for Navigation Signal Timing and Ranging Global
Positioning System.
Copyright 2001 - Andrews Space & Technology
Andrews Space & Technology Privacy
Statement and Copyright Information
SPACEandTECH Digest is a weekly roundup of the latest industry news of interest
to the space professional. SPACEandTECH Flash! is an internet push
service offered by Andrews Space & Technology to bring the
latest on orders, launches, and important breaking news to your
desktop. SPACEandTECH Digest and SPACEandTECH Flash! are part of
the Andrews Space & Technology www.spaceandtech.com
website, a website designed to serve the information needs of the
space industry.
If you would like to subscribe to the SPACEandTECH
Flash!
(currently a free service), contact the www.spaceandtech.com
Editor-in-Chief, Joe Hopkins, at editor@spaceandtech.com
|
