Image copyright: Solar Impulse 2014
Innovative plastics from Bayer MaterialScience have been used to construct parts of a futuristic aircraft that is aiming to be the first to complete a round-the-world flight without fuel in 2015.
The new, second-generation Solar Impulse aircraft is an advancement of the first prototype, which in 2010 demonstrated the feasibility to fly day and night using only solar energy. Since then it has successfully completed numerous flights, most recently a coast-to-coast journey across the United States.
On board are numerous products and solutions from Bayer MaterialScience that make the plane especially lightweight and energy efficient, including Baytherm Microcell, an efficient insulating material used for the cockpit.
The insulating performance of Baytherm Microcell is said to be as much as 10 percent greater than the current standard. Highly efficient insulation is particularly important for the aircraft because it must withstand temperature fluctuations between minus 40°C at night and plus 40°C degrees during the day.
Baytherm Microcell is used for the aircraft door, while the rest of the cockpit shell is made of a different type of rigid polyurethane foam from Bayer. The company also supplies a polyurethane/carbon fibre composite material for the door locks, and thin sheets of transparent, high-performance polycarbonate for the window. Although the cockpit is larger overall than in the first prototype, it is only minimally heavier.
Outside the cockpit, rigid polyurethane foam is used to insulate the batteries. Bayer also provides the raw materials for the silvery coating covering large portions of the aircraft and the adhesives that hold the textile fabric in place underneath the wings.
"The Solar Impulse initiative is both scientific and innovative. It is also philosophical, by its goal of raising awareness in society about the need to save our planet’s energy resources,” commented Bertrand Piccard, one of the solar Impulse project’s founders. “Without Bayer and its mission of conducting ‘Science For A Better Life’ this solar airplane would never have been light and efficient enough to be able to fly night and day without fuel.”
On its historic journey around the world, the plane is to be powered solely by the sun. The energy will be generated by roughly 17,200 solar cells on the wings, which at 72 metres have a span equal to that of the largest passenger airliners. The entire aircraft, however, only weighs 2.3 tonnes.
The second model will undertake a number of test flights this year as well, prior to setting off on its main mission in March 2015.