Satellite Substitutes Save the Day

The U.S. Department of Defense has known for several years that it cannot afford sufficient satellites to meet the growing demand for communications satellites. The commsats cost at least $250 million each, and even the much touted micro-sats still cost about ten percent of that. One of the more imaginative alternatives turned out to be things like weather balloons equipped with satellite commo gear. The high altitude "satellite replacement" balloons are based on existing weather balloon designs, but carrying communications gear instead of weather sensors. As long as you can pick up and broadcast the same kind of signals commsats handle, you can put the equipment in a high altitude (up to 100,000 feet) balloon, or even a bomber or tanker that spends hours circling the battlefield. Much of the satellite communications needed by combat troops is with other people in the same general area. So the commsat replacement (a balloon or B-52) can do the job, passing off the long distance stuff to the real commsat.

A balloon can cover troops needs for about a thousand kilometers in all directions. A B-52 or KC-135 tanker can deal with a smaller area, but is even cheaper than $25,000 balloon, which is often only good for a few missions. Once launched, the balloon turns on its battery powered transponder when it has reached the proper altitude, maintaining its position like a hot air balloon, using computerized controls. It acts like a very low flying satellite until the battery runs out after 8-12 hours. Then the balloon deflates, a parachute brings it to earth in one piece, and a GPS beacon makes it possible for the equipment to be recovered for reuse.

One of the more useful aspects of balloons is that they are easy to carry, and can be inflated and launched by a Special Forces team out in the middle of nowhere. Special Forces recon teams often want to send back live video of whoever they are keeping an eye on. These balloon sats make that easier, because they can also carry satellite grade sensors (various types of night and day cameras).

The major cause of more commsat use is live video being generated by the increasing number of vidcams on the battlefield. These vids are being exchanged by the units cooperating in an operation. Since that's all local, a "satellite substitute" (a balloon, or aircraft carrying the comm. Gear) will work. To that end, there are even plans to put the comm gear in UAVs, including special UAVs that just fly circles high in the sky, acting as satellite substitutes. These substitutes cost less than ten percent, per hour in use, of what satellites cost.

The satcomm shortage problem began during the 1990s, when 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, not all 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 substitutes are becoming more common, simply because there is neither the money, nor the time, to get sufficient satellites into orbit.