The United States Marine Corps is testing a personal satellite radio in Iraq. The 24 ounce ETCS (Expeditionary Tactical Communications Systems) uses the Iridium satellite phone system, and the marines want to see how effective such a radio is. Satellite phone technology is expensive to use (even buying bulk, it still costs about 25 cents a minute for U.S. Department of Defense users), and the marines want to see if the troops find it useful enough to justify the expense. Most existing military radios are FM, meaning they broadcast a line-of-sight signal that can be blocked, or weakened, by hills, or even buildings. But satellite phones are also line-of-sight, except that everyone sends and receives signals from the satellites overhead. In this case, you always have some problems when you take your satellite radio indoors, or underground.