Solar Impulse Project
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This aircraft article is missing some (or all) of its specifications. If you have a source, you can help Wikipedia by adding them.Solar Impulse is a long-range solar plane project currently under study at the EPFL. The project is advertised by Bertrand Piccard, and aims at completely solar circumnavigation.
The aircraft is intended to be a one-seater, capable of taking off autonomously on its solar system, and to remain airborn for days. Once the efficiency of the batteries makes it possible to reduce the weight, a two-seater is planned to make circumnavigation possible.
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[edit] Project
[edit] Timesteps
- 2003: Feasibility study at the École Polytechnique Fédérale de Lausanne.
- 2004-2005: Development of the concept.
- 2006: Simulation of long-haul flights.
- 2006-2007: prototype.
- 2008-2009: prototype test flights
- 2009-2010: construction of the final plane
- 2011: several day-missions, crossing the Atlantic and trials circumnavigating the globe in five stages
Take-off should occur in May 2011, for a flight around the world near the equator, but essentially in the northern hemisphere. Five stops are planned to change pilots. Each leg will last three to four days, limited by the endurance of the pilot.
[edit] Aerodynamics
The wingspan of Solar Impulse is 80 metres, slightly wider than the wingspan of an Airbus A380, in order to minimise drag and offer a maximum surface for solar cells. Such light wing loading (8 kg/m²) creates greater sensitivity to turbulence. The ultra-light structure must use customised carbon fibres.
| Max. altitude | 12,000 m |
| Max. weight | 2000 kg |
| Average speed | 70 km/h |
| Wingspan | 80 m |
| Max. power of motors | 35 kW |
| Battery weight | 450 kg |
| Battery capacity | 200 Wh/kg |
| Photovoltaic efficiency | 0.2 |
[edit] Structure
While traditional sandwich composites have an area density in the order of 10 kg/m², those developed for Solar Impulse should weigh in the order of 0.5 kg/m². These materials could also have functionality integrated, such as integrity sensors, active control of the form, etc.
A layer of ultra-thin solar cells will be integrated to the wings. These cells are designed to be flexible enough to sustand deformations and vibrations.
[edit] Energy
Energy captured during the day will serve both to propel the plane and to recharge the batteries to allow fly at night. Energy is accumulated during the day in lithium batteries in the wings, the density of which must be close to 200 Wh/kg, in spite of temperatures ranging from +80 C to –60 C.
[edit] Propulsion
The average power provided to the engines is in the order of 12 HP, comparable to that of the Wright Flyer.
[edit] Cockpit
The cockpit will provide pressurisation, oxygen and various environmental support to the pilot to allow a cruise altitude of 12 000 metres.
[edit] Partners
The project is partially financed by private companies such as Deutsche Bank, Solvay, Omega and Altran. The EPFL, the European Space Agency (ESA) and Dassault provide technical expertise.
[edit] See also
- Helios Prototype, the NASA experimental unmanned solar aircraft.
