Going Forward - GPS Declassified: From Smart Bombs to Smartphones - page 184

with the signals. Assuming the United States and Great Britain resolve the pat-
ent issues discussed in the preceding chapter, gps iii will introduce a fourth
civilian signal (l1c) that is interoperable with Europe's Galileo, Japan's qzss,
and potentially with China's Beidou. 2 Navigational accuracy will be three times
better than with the Block iif satellites. The gps iii's user range error over
twenty-four hours will be within one meter, versus the current three meters. 3
gps iii will broadcast military signals three times more powerfully, making
jamming by an adversary more difficult.4 4 Lockheed Martin's subcontractor on
the navigation payload, itt, has participated in building that component in
every generation of gps satellites for more than thirty years. 5
How soon the new satellites will deliver these capabilities depends not only
on the launch schedule and completion of the new ocx ground control system
but also on fielding new receivers designed to take advantage of the new fea-
tures. gao in March 2012 warned, “User equipment is not expected to be fully
fielded to the warfighters until many years later, possibly as late as 2025.” 6
Lockheed Martin, which built twenty-one Block iir satellites and “modern-
ized” the last eight of them (iir[m]), designed gps iii from the start to insert
new capabilities as future space vehicles (svs) are built. 7 Although the Air Force
to date has ordered eight gps iii satellites, the 2008 contract has an option for
up to a dozen. Lockheed Martin publicity materials indicate the Air Force may
build as many as thirty-two gps iii satellites. 8 The ninth and later svs will sup-
port the Distress Alerting Satellite System, a nasa-led international program
using gps and Galileo satellites to relay signals from emergency beacons to
search- and- rescue teams. 9 By replacing a current analog component with a
digital waveform generator, gps iii satellites will be equipped to generate new
types of signals after they are already in orbit. 10 Each gps iii will carry three
rubidium atomic frequency standards but will have an open slot for a fourth
atomic clock. For the first time, ground controllers will be able to turn on and
monitor this backup clock separately from the operational clocks, giving them
the ability to study experimental designs, such as a hydrogen maser. 11 These
expandable features are important because the design life of each gps iii sat-
ellite is fifteen years. The record of technological change during any fifteen-
year period since the satellite age arrived suggests how quickly high-tech
equipment can become obsolete. If gps iii longevity matches that of earlier
generations, some satellites launched in the 2015-16 period could still be orbit-
ing and operational in 2038 or beyond.
gps iii satellites may repeat the pattern of gps iia, iir, iir(m), and iif, with