May 2, 2008 Aurora Flight Sciences has revealed the design of the aircraft it hopes will achieve the ambitious goals set out in DARPA's ambitious Vulture program: sustained uninterrupted flight for over five years at altitudes of 60,000-90,000 feet. Known as Odysseus, the solar-powered concept aircraft is as radical as the mission it is designed to accomplish, combining three self-sufficient “constituent aircraft” in a unique Z wing configuration that spans almost 500 feet (150 meters). The modular design provides several advantages - the shape of the aircraft can be adjusted to maximize the solar collection properties during the day and spread flat for aerodynamic efficiency at night-time, when energy stored in onboard batteries is used to drive the aircraft's electric motors. Because each of the constituent vehicles is capable of autonomously docking at altitude, the design also facilitates the replacement of one section of the plane whilst it is still aloft, meaning continuous flight can be maintained even if something goes awry.
Designed to fly in the stratosphere, Odysseus will be used for surveillance and reconnaissance, communications relay and environmental monitoring with the potential for roles in global climate change research and regional-scale telecommunications.
Each autonomous section of the plane has three high efficiency electric brushless motors turning Low Reynolds number propellers giving the aircraft the ability to cruise at 63 m/s during daytime and 45 m/s during nighttime and carry a payload of 500kg. The onboard batteries are designed to be recharged each day via double sided cells optimized for energy collection efficiency at high latitudes, and adding to the redundancy built in to the plane's architecture, Odysseus' electronics are adapted from spacecraft designs which have already proven their reliability in missions lasting several years.
One of three contractors recently chosen for the Vulture program (along with Boeing and Lockheed Martin), Aurora Flight Sciences will develop a half scale demonstrator followed by a full scale prototype aircraft in 5 years.
The company was formed in 1989 by the former head of the Daedalus Project, Dr. John S. Langford, and several colleagues from M.I.T. and Harvard. BAE Systems (sensors and concept of operations), C.S. Draper Laboratories (ultra-high-reliability electronic controls), and Sierra Nevada Corporation (the rendezvous and docking system) will also contribute to the Odysseus program.
