Going Forward - GPS Declassified: From Smart Bombs to Smartphones - page 190

and the patterns since 1859 to try to predict the frequency of a Carrington-level
solar flare, with estimates ranging from once in two hundred to five hundred
years. 37
Sharp Elbows in Space
International conflicts on the ground seem increasingly likely to escalate to
space, given today's strategic reliance on navigation, surveillance, and com-
munication satellites. Even if governments avoid confrontations that threaten
satellites, avoiding accidents will require better systems and improved coop-
eration. An unclassified January 2011 summary of the National Security Space
Strategy prepared by the Department of Defense and the National Intelligence
Agency described the situation this way: “Space is becoming increasingly con-
gested, contested, and competitive.” 38 Since the Vanguard satellite launched
in 1958 (it is still orbiting), the number of man-made objects in Earth orbit that
the Defense Department tracks has increased to about 22,000, including
around 1,100 active satellites and about half as many rocket bodies. 39 The mil-
itary actively monitors objects ten centimeters (about four inches) in diameter
and larger because a direct hit could destroy a satellite. 40 However, nasa esti-
mates there are a half-million particles between one centimeter and ten cen-
timeters in diameter in low Earth orbit—below 1,250 miles (2,000
kilometers)—that could damage satellites, the Hubble telescope, or the Inter-
national Space Station in an impact. 41 Fortunately, gps satellites are in mid-
Earth orbits ten times that distance, but they will be just as vulnerable if
present trends creep to higher altitudes.
Debris has increased dramatically over the past few years because of satel-
lite breakups and collisions and an antisatellite (asat) test by China. In 2009
an inactive Russian government Cosmos satellite collided with an active U.S.
commercial Iridium satellite about 497 miles above Siberia, destroying both
and adding 1,500 to 2,000 pieces of space debris. 42 It was the first reported
collision between two satellites in orbit, although a rocket fragment struck and
damaged a French satellite in 1996. 43 After the 2009 incident the U.S. military
established a warning system for close approaches of all satellites it tracks, and
the European Union proposed an international code of conduct for outer
space. 44 U.S. opponents balked at any agreement that might limit military
options, but the Defense and State Departments eventually endorsed the con-
cept in January 2012, expressing confidence that they could create a code of
conduct that did not constrain national security-related space activities. 45 That