Going Mainstream - GPS Declassified: From Smart Bombs to Smartphones - page 147

“selective deniability.” This means the ability to deny adversaries the use of
gps signals in specific areas where U.S. troops are engaged in operations, with-
out affecting the signals elsewhere. At the same time, U.S. forces or allies must
be able to continue using the military signals and to overcome any adversary's
attempts to block them through jamming. gps signals from space are very faint
and can easily be jammed using inexpensive equipment. The 9/11 attacks has-
tened development of sophisticated antijamming techniques and electronic
warfare countermeasures. 194
At 9:25 a.m., September 11, thirty-nine minutes after the first plane struck
the North Tower, Ben Sliney, the national operations manager at the faa's com-
mand center in Herndon, Virginia, ordered a full nationwide ground stop. No
flights, private or commercial, could take off. It was the first time anyone had
given such an order, and it was his first day on the job. 195 Twenty minutes later,
after Flight 77 crashed into the Pentagon, Sliney ordered every plane in U.S.
airspace—nearly 4,500 of them—to land. 196 Within an hour about three-
quarters of them were on the ground, and by 12:16 p.m. the only planes in the
air were military aircraft or emergency flights.197 197 Controllers diverted hundreds
of international flights en route to the United States. The faa halted civil avia-
tion for two full days and lifted restrictions gradually, starting with airlines and
then charter and corporate flights. General aviation restrictions remained until
mid- December. 198 Despite these unprecedented circumstances, authorities at
no time disrupted the gps Standard Positioning Service. On September 17, 2001,
the Interagency gps Executive Board (igeb) posted a statement on its website
reaffirming that the U.S. government had “no intent to ever use sa again.” 199
Some nations, however, continued to chafe at their growing dependence on
gps, fearing that the United States could “wreck their economies with the flick
of a switch.” 200 One month after the igeb notice, international aviation offi-
cials gathered for the icao conference in Montreal pressed the United States
on unresolved gps issues, and the Europeans in particular pushed for some
type of binding international regime. 201 While Russia's glonass system, which
attained a full complement of twenty-four satellites in 1995, had deteriorated
by 2001 to just six operational satellites, the eu forged ahead with its plans to
have thirty Galileo satellites in place by 2008. 202
This emerging competition for global navigation satellite superiority raised
political and security concerns about whether Galileo's signals would interfere
with gps's military bandwidth. 203 After protracted negotiations, with the Iraq
War raging in the background, the State Department announced in June 2004