The U.S. Air Force recently announced that the long anticipated new
generation of military communications satellites, planned for first launch in
2013, would be delayed another six years. The problem is a common one. The TSAT
(Transformational Communications Satellite System) depends on a lot of new
(some not yet invented) technologies, and lots of unwritten software. That
produces uncertainty, and more delays.
the last decade, the U.S. Department of Defense has been trying to design,
build and put into orbit a new generation more powerful military communications
satellites. This has not gone well. Four years ago the Department of Defense
came up with TSAT. This was basically a satellite based military Internet. It
was optimized for speed. Right now, it takes about two minutes to get a UAV
image to another user via satellite. TSAT would do that in a second or two.
This kind of speed is needed if all the air, land and sea weapons are linked
together, to act as observers and shooters for each other. The only drawbacks
with TSAT is that such a system will cost nearly $20 billion, and take over a
decade, to build. While this has many of the brass ready to sign on, others are
casting about for cheaper and faster solutions, using existing technology to
work up to the TSAT gold standard year by year.
the Department of Defense is trying to deal with demand by putting a bunch of
WGS (Wideband Gapfiller Satellite, since renamed as Wideband Global Satcom)
birds in orbit. These are 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 satellites.
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.
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 its 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.
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.
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, and the
TSAT system developed and in orbit.
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
solution was the WGS birds, with the first one going up in 2007. 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, sort of, and the second WGS bird will be launched in 2009, and the
remaining four by 2013 (maybe). That will provide nearly 20 gigabits of
capacity, which will still not be enough.