By Mary Grady, Contributing editor
Two large tethered helium blimps carrying surveillance gear will be deployed for testing by the North American Aerospace Defense Command, known as NORAD, somewhere near Washington, D.C.'s airspace by the end of September, Reuters reported this week. The blimps, each of them about 243 feet long, can reach altitudes up to 10,000 feet and stay aloft for up to 30 days at a time. They will carry radar and other surveillance gear that enables them to detect ground targets, manned and unmanned aircraft, boats, and cruise missiles at distances up to 340 miles. They cost about $450 million for the pair.
The test period is expected to last up to three years, according to Reuters. The blimps are tethered to mobile mooring stations. One of them carries surveillance radar with 360-degree capability, and the other one carries a fire-control radar. Raytheon, which builds the system, says expected costs to operate the pair of blimps should be about 5 to 7 times less than operating costs for large, fixed-wing surveillance aircraft. No location has been released for the blimps' deployment.