STEPHEN TRIMBLE / WASHINGTON DC
The US Missile Defense Agency (MDA) is reviewing potential sensor and communications payloads for a solar-powered high-altitude airship (HAA).
Lockheed Martin has been awarded a $40 million contract to complete designs of a prototype airship that can provide cruise missile detection, border security and coastal surveillance. A demonstration effort could begin next summer under an additional $50 million contract, including a first flight in mid-2006. Sensor and datalink technologies have not been defined, however.
MDA envisages a network of around a dozen airships hovering for up to a year above 65,000ft (19,800m). "As you can imagine, some types of surveillance, communications and other payloads are likely candidates, but there's been no specificity in terms of what we might be looking at," says Ron Browning, Lockheed Martin's HAA business development director.
A key challenge for payload designers is reliability, Browning adds. The prototype's payload must operate for a minimum of 30 days without maintenance, and MDA hopes to extend continuous flying to up to a year. "There's a challenge here for long-term reliability when you're on station," Browning says.
Another area of technology that is still emerging is the airship's power supply - a non-metallic, photovoltaic (PV) skin wrapped across the top half of its 160ft diameter frame. PV suppliers have proposed designs, but the airship programme would be the first test of the technology on such a scale. Other PV applications include a wearable skin on a soldier's uniform.
The HAA would be parked in an altitude band ranging from 65,000ft to 72,000ft - beyond commercial airspace and most wind currents. Lockheed Martin's team is led by its Maritime Systems and Sensors unit in Akron, Ohio, which produces commercial airships.
Source: Flight International
