SolarStratos aircraft
The plane is covered in solar cells that power the craft's propellorsSolarStratos

Swiss engineers have developed a plane that they claim is capable of reaching the edge of space using solar power alone. The stratospheric aircraft, created by engineering firm SolarStratos, can fly at an altitude of over 82,000 feet using only the sun's energy and can remain airborne for more than 24 hours.

SolarStratos wants its 8.5 metre-long aircraft to be the first manned, solar-powered plane to penetrate the stratosphere, the outer fringes of the atmosphere that separates the sky from space. The two-seater plane has a wingspan of 24.8 metres and is covered in 22 square metres of solar panels, which harness sunlight to power the craft's electric engine.

This in turn powers a single four-blade propeller at the front of the craft, which, combined with a 20kW/h lithium-ion battery, makes the aircraft entirely emission-free.

Project head Raphael Domjan is the brains behind PlanetSolar, the first solar-powered boat to circumnavigate the globe in 2012. "Our goal is to demonstrate that current technology offers us the possibility to achieve above and beyond what fossil fuels offer," he said in a statement.

"Electric and solar vehicles are amongst the major challenges of the 21st century. Our aircraft can fly at an altitude of 25,000 metres and this opens the door to the possibility of electric and solar commercial aviation, close to space."

SolarStratos and pilot
The pilot will be required to wear a space suit as the plane isn't pressurisedSolarStratos

Domjan will pilot the first flight to the earth's outer reaches in 2018, reports Digital Trends. The five-hour mission will involve a two-hour climb to the stratosphere, where the plane will spend a further 15 minutes before making the three-hour descent back to the ground. Domjan will be required to wear a pressurised space suit throughout the journey.

The SolarStratos aircraft was unveiled by its creators on 8 December in Payerne, Switzerland, in front of 300 guests that included representatives from the Swiss government.

Roland Loos, CEO of parent company SolarXplorers, said: "We are extremely pleased with the positive feedback and encouragement that we have received. Our project brings hope and makes both children and adults dream. It also opens the door to new scientific knowledge – at an affordable price, exploration and the peaceful use of our stratosphere."