The first solar-powered aircraft that could fly around the world is now under construction. If all goes well, the Solar Impulse will make its first flight in 2009, with a second version attempting circumnavigation in 2011.
"It's no longer a concept. It's concrete," said the company’s Phil Mundwiller at EBACE. "We raised 65 million Swiss francs [$53 million]. The global budget is 100 million, so we have 65% of the budget."
The prototype started construction in April and will be completed by summer 2008, he says, and ready for a 36-hour flight in 2009. "We will build the full airplane in 2010."
The final flight in 2011 will travel near the equator in four or five legs of three days each, with a new pilot on each leg and publicised receptions at each landing.
The 61m (200ft) wingspan is covered with flexible ultra-thin monocrystalline silicon solar panels, as is the broad tail, and a "tortuous flight path" will navigate around cloud cover at 38kt (70km/h) on average.
The Solar Impulse will gain altitude during the day and descend during the night with power from advanced lithium batteries weighing 450kg (990lb). Power directly from the Sun generates 12hp (9kW) on average across a day and night – the same power available to the Wright brothers in 1903.
The unpressurised cockpit will hold one hearty pilot who will endure temperature and pressure changes at elevations up to 12,000ft. The final model will be pressurised, with wings 80m across and a total weight of 2,000kg. Most of the aircraft is made of carbonfibre.
Solvay, Omega and Deutsche Bank are the primary partners of the Lausanne, Switzerland-based team. Altran is the engineering partner. Mundwiller points out that the projected timeline may need to be flexible. "Nobody knows, because we are building something no-one has built before."
Source: Flight Daily News
