Posted by Graham Warwick at 4/24/2009 12:17 PM CDT
An unmanned airship could be conducting weeks-long persistent ISR missions over Afghanistan within 18 months, if the US Army gets any takers for its latest sources sought notice. Space and Missile Defense Command (SMDC) is looking for a prototype of a hybrid airship called the Long Endurance Multi-payload Vehicle (LEMV). Requirements include a three-week endurance, station-keeping at 20,000ft altitude while carrying a 2,500lb, 16kW multi-INT payload.
At first glance the requirement looks a reasonable fit for something like Lockheed Martin's High Altitude Long Endurance Demonstrator (HALE-D) - a subscale prototype of the proposed solar-powered stratospheric High-Altitude Airship (HAA). Except for that reference to "hybrid airship", which normally connotes a vehicle combining lighter-than-air and heavier-than-air characteristics, and using buoyancy, aerodynamics and vectored thrust for lift. Think of DARPA's defunct Walrus uber-lifter program, or the Skunk Works' P-971, seen here:
The solar-powered HALE-D, which is already being funded by SMDC and is due to fly in August, is a pure airship designed to demonstrate station-keeping at 60,000ft, with the goal of exceeding two week's endurance. And it will carry only a 50lb payload. The full-size HAA would carry a 2,000lb/15kW payload at 65,000ft for more than 30 days - but is a long way from being built.
SMDC is also funding the HiSentinel solar-powered stratospheric airship demonstrator developed by Southwest Research Institute and Aerostar International, but that carries only an 80lb/500W payload. So where will the LEMV prototype come from? For a possible clue, check out Hybrid Air Vehicles Ltd. The latest incarnation of Airship Industries and Advanced Technologies Group, the UK-based company says it is flying a subscale demonstrator of a unmanned hybrid airship...
