Initiated in 2014 by the Swiss pilot Raphaël Domjan, the SolarStratos project aims to achieve a technological exploit: to reach the strato- sphere at an altitude of 25,000 metres with an airplane powered exclusively by photovoltaic solar energy. The goal of this adventure is to prove that, using today’s technology, it’s possible for vehicles to per- form beyond the potential of fossil fuels. Electric and solar-powered vehicles are among the greatest challenges of the 21st century, and the SolarStratos project paves the way for tomorrow’s mobility.
SolarStratos is a two-seat airplane designed by Calin Gologan from the company PC-Aero GmbH. It is powered by two electric 19 kW motors that rotate a three-blade propeller with a 1.75-meter diameter. The wings are covered with 22 m2 of the latest-generation solar cells, whose conversion rate is between 22 and 24%. They charge lithium- ion batteries with a total capacity of 14 kWh, extendable to 21 kWh.
But for the record-setting flight, the plane will leave the hangar with uncharged batteries, which will be recharged by solar energy before departure and upon landing. At the end of the flight, they should have stored at least as much power as at take-off in order to attest that the entire flight was effectively 100% powered by solar energy. A new pro- peller will also be installed, optimised for the ascent into the strato- sphere.
The stratospheric flight is scheduled for 2023. In the meantime, SolarStratos aims to beat the current record for a fully electric and solar flight set by Solar Impulse in 2014 at an altitude of 9,400 meters. According to the website SolarStratos.com, the mission in the strato- sphere should last approximately 6 hours, including a 3-hour ascent toward space (“15 minutes with our head in the stars”, then 3 hours to come back down to Earth). Both the aircraft and the pilot Raphaël Domjan will be subject to extreme temperatures, in the region of -70°C.
