About three years late, the U.S.
Department of Defense is ready to launch its first new communications
satellite. These WGS (Wideband Gapfiller Satellite) are actually modified
versions of the Boeing 702 communications satellite. Boeing has orders for 19
of these, which are built on the earlier, and very successful, 600 series communications
Seemed like a slam-dunk, basing needed military
commo birds on a solid civilian model. A few tweaks and additions to deal with
military security needs, and off we go. The Department of Defense wants to
build six WGS birds, at a cost of some $220 million each. The WGS has ten times
the throughput (three gigabits) of the earlier DSCS III commo satellites. The
first WGS bird in orbit would more than double the transmission capacity of the
Department of Defense satellite system.
There is a growing need for more commo birds.
Between 2000 and 2002, Department of Defense satellite bandwidth (data
transmission demand) doubled, and more than doubled every 18 months after that.
Back in 2000, some 60 percent of Department of Defense satellite capacity had
to be leased from commercial firms. While the Department of Defense had it's
own communications satellite network (MILSAT), it underestimated the growth of
demand. Greater use of the internet and reconnaissance aircraft and UAVs using
video cameras quickly used up MILSATs capacity and forced the military to lease capacity on commercial satellites. This
was done on the "spot market," meaning the Department of Defense had
to pay whatever the market would bear at that moment. Since the military needed
more capacity because of combat operations, the media was also in the market
for more capacity to cover the war. The Department of Defense paid more than
ten times as much as it would have if it had leased (for one to fifteen years)
satellite capacity earlier. The situation was made worse by the fact that it
was an emergency situation, so every heavy user of satellite communications was
making their own deals. This resulted in some users (air force, or, say, the
Atlantic Fleet) having some extra capacity when someone else, like Army Special
Forces, was still short.
During the 1990s, the U.S. armed forces moved to
satellite communications in a big way. This made sense, especially where troops
often have to set up shop in out of the way places and need a reliable way to
keep in touch with nearby forces on land and sea as well as bases and
headquarters back in the United States. At the time of the 1991 Gulf War, there
was enough satellite military communications capacity (commonly known as
"bandwidth") in the Persian Gulf for about 1300 simultaneous phone
calls. Or, as the geeks put it, 100 mega (million) bits per second. But while
the military has a lot more satellite capacity now (the exact amount is a
secret), demand has increased even faster. UAV reconnaissance aircraft use
enormous amounts of satellite capacity. The Global Hawk needed 500 megabits,
and Predators about half as much. The major consumer of bandwidth is the live
video. UAVs have other sensors as well, as do aircraft. A voice radio connection
only takes about 2,000 bits per second, and each of the multiple channels
needed to control the UAVs use about the same. But it adds up, especially since
the military wants high resolution video. At the moment, the U.S. has far more
demand for satellite communications than it can support. As a result, less than
half the Predator and Global Hawk UAVs in combat zones have sufficient
bandwidth to send their video back to the United States. Data compression and
using lower resolution is often necessary, or using satellite substitutes
(aircraft carrying transponders) to send the video to local users.
With the growing number of UAVs, ship, ground
vehicle and aircraft requirements for bandwidth, the Department of Defense
expects to need more than 16 gigabits (thousand megabits) by 2010. Thus the rush
to get those WGS birds up.
Attempts to get capacity from civilian satellites
was complicated by the fact that there was a shortage there as well. This was
created by the tremendous overbuilding of fiber optic cable networks on the
ground (and under oceans) in the late 1990s. This provided cheaper bandwidth
for civilian uses and has meant fewer communications satellites being put up.
In fact, the fiber optic glut reduced planned satellite launches by some 60
percent for the first few years of this decade.
The solution was the WGS birds, with the first one
going up in 2004. But there were design problems, manufacturing problems, and
scheduling problems getting an American launcher (having a Russian or Chinese
rocket put these birds into orbit was not an option, for security reasons.)
These problems have been solved, and two WGS birds will be launched this year,
with another next year, and the remaining three by 2013. That will provide
nearly 20 gigabits of capacity, which will still not be enough.