US military's airship programs lose altitude: The US military has invested billions in blimp-like aircraft to track militants planting roadside bombs but the spyship experiment is losing altitude because of technical failures and changing priorities.
The lighter-than-air projects were billed as an innovative revival of an old aircraft design to conduct "unblinking" surveillance on the battlefield -- at a fraction of the cost of fuel-guzzling planes or helicopters.
The Pentagon invested $7 billion in airship programs between 2007 and 2012, but the funding has mostly dried up amid budget cuts and embarrassing setbacks.
Tethered balloons equipped with radar have been used routinely for surveillance by US forces over the past decade and are a common sight floating over American bases in Afghanistan.
But the big money went towards airships, which are a step up from the "aerostats" held by ropes. The airships fly on their own power similar to the zeppelins of the World War I era, while carrying more technology on board.
