2007-11-11 - Solar Impulse updateSolar Impulse test aircraft built
Solarflugzeug im Bau<br /> The Solar Impulse project has entered a concrete phase with the construction of an initial prototype with a 61-metre wingspan, referred to by its registration number "HB-SIA".
Its mission is to verify the working hypotheses in practice and to validate the selected construction technologies and procedures. If the results are conclusive, it could make a 36-hour flight - the equivalent of a complete day-night-day cycle -Construction of the first prototype, the HB-SIA, began in June 2007 and will last until the summer of 2008. Test flights should start in autumn 2008, with the objective of completing the first night flight in 2009. Another plane will then be developed to attempt to fly several 24-hour cycles consecutively, leading to the first trans-Atlantic flight in 2011, and then the first round-the-world flight. This is a "basic" prototype airplane. The instrument panel will be reduced to the essentials, and with a non-pressurized cockpit it will be unable to fly above 8,500 m. It will be a first approach at optimizing the balance between energy consumption, weight, performance and controllability. The goal is not to try to fly around the world and indeed the HB-SIA is not built to do so.
The objectives at this stage are: To validate the computer simulation results, the technological choices and the construction techniques; to test an unexplored area of flight: never before has an airplane succeeded in flying with these size, weight and speed characteristics; to store sufficient solar energy during the daytime to demonstrate the feasibility of a day-night-day cycle (36-hour flight). Current solar airplanes are not designed to store energy and therefore have to land in cases of insufficient sunlight (clouds or night time). In so doing they mark the limits of solar energy. Other projects are seeking to fly remote controlled solar drones or hydrogen-powered airplanes. To demonstrate the formidable potential of renewable energies, Solar Impulse intends to place the bar much higher and have a piloted aircraft fly night and day without fuel.